| characterization of a spinach psbs cdna encoding the 22 kda protein of photosystem ii. | an intrinsic 22 kda polypeptide is found associated with the oxygen-evolving photosystem ii (psii) core complex in all green plants and cyanobacteria so far examined, although it does not appear to be required for oxygen evolution. amino acid sequence information obtained from the purified 22 kda protein was used to construct a probe that was employed to isolate a full-length cdna clone encoding the 274-residue precursor of the 22 kda protein. hydropathy plot analysis predicts the existence of f ... | 1992 | 1451805 |
| isolation and characterization of a sucrose carrier cdna from spinach by functional expression in yeast. | active loading of the phloem with sucrose in leaves is an essential part of the process of supplying non-photosynthetic tissues with carbon and energy. the transport is protein mediated and coupled to proton-symport, but so far no sucrose carrier gene has been identified. using an engineered saccharomyces cerevisiae strain, a cdna from spinach encoding a sucrose carrier was identified by functional expression. yeast strains that allow the phenotypic recognition of a sucrose carrier activity were ... | 1992 | 1464305 |
| isolation and kinetic properties of acetohydroxy acid isomeroreductase from spinach (spinacia oleracea) chloroplasts overexpressed in escherichia coli. | acetohydroxy acid isomeroreductase catalyses a two-step reaction, an alkyl migration and a nadph-dependent reduction, in the assembly of the carbon skeletons of branched-chain amino acids. detailed investigations of acetohydroxy acid isomeroreductase aimed at elucidating the biosynthetic pathway of branched-chain amino acids and at designing new inhibitors of the enzyme having herbicidal potency have so far been conducted with the enzymes isolated from bacteria. to gain more information on a pla ... | 1992 | 1472001 |
| iron-sulfur centers as endogenous blue light sensitizers in cells: a study with an artificial non-heme iron protein. | the possible involvement of fe-s clusters in photodynamic reactions as endogenous sensitizing chromophores in cells has been investigated, by using an artificial non-heme iron protein (anhip) derived from bovine serum albumin and ferredoxins isolated from spinach and a red marine algae. ferredoxins and anhip, when exposed to visible light, generate singlet oxygen, as measured by the imidazole plus rno method. irradiation with intense blue light of the anhip-entrapped liposomes caused severe memb ... | 1992 | 1508984 |
| immobilized ferredoxins for affinity chromatography of ferredoxin-dependent enzymes. | an immobilized ferredoxin more stable than the conventional immobilized spinach ferrodoxin was prepared by reacting cnbr-sepharose with ferredoxins isolated from barley and synechococcus vulcanus, a thermophilic blue-green alga. the dissociation constants of immobilized ferredoxin from spinach, barley and s. vulcanus for spinach ferredoxin-nadp reductase were 0.922, 2.505 and 5.209 microm, respectively, whereas those for barley ferredoxin-nadp reductase were 1.159, 0.579 and 2.851 microm, respec ... | 1992 | 1517310 |
| molecular cloning and bacterial expression of cdna encoding a plant cysteine synthase. | cysteine synthase (csase) [o-acetyl-l-serine acetate-lyase (adding hydrogen sulfide), ec 4.2.99.8] catalyzes the formation of l-cysteine, the key step in sulfur assimilation in plants, from o-acetyl-l-serine and hydrogen sulfide. we report here the isolation and characterization of cdna clones encoding cysteine synthase from spinach (spinacia oleracea l.). internal peptide sequences were obtained from v8 protease-digested fragments of purified csase. a lambda gt10 cdna library was constructed fr ... | 1992 | 1518833 |
| variable intron content of the nadh dehydrogenase subunit 4 gene of plant mitochondria. | the gene nad4, encoding subunit four of the mitochondrial nadh dehydrogenase complex i, has been isolated and characterized from turnip, brassica campestris. the 8 kb turnip nad4 gene contains four exons, which potentially encode a nad4 polypeptide of 495 amino acids, and three large group ii introns. northern analysis identifies an abundant 2 kb transcript that most likely serves as the nad4 mrna, while several larger transcripts (putative splicing intermediates) are also detected. analysis of ... | 1992 | 1525869 |
| over-expression and refolding of beta-subunit from the chloroplast atp synthase. | we established a bacterial system for high-level over-expression of the spinach chloroplast atpb gene which encodes the atp synthase beta subunit. upon induction, atpb was expressed as at least 50% to 70% of total cell protein. although the over-expressed beta polypeptide formed insoluble inclusion bodies, more than fifty percent of it was restored to a functional form by solubilizing the inclusion bodies with 4 m urea and slowly removing the urea by stepwise dialysis. the resulting beta subunit ... | 1992 | 1531962 |
| nuclear-encoded chloroplast ribosomal protein l12 of nicotiana tabacum: characterization of mature protein and isolation and sequence analysis of cdna clones encoding its cytoplasmic precursor. | poly(a)+ mrna isolated from nicotiana tabacum (cv. petite havana) leaves was used to prepare a cdna library in the expression vector lambda gt11. recombinant phage containing cdnas coding for chloroplast ribosomal protein l12 were identified and sequenced. mature tobacco l12 protein has 44% amino acid identity with ribosomal protein l7/l12 of escherichia coli. the longest l12 cdna (733 nucleotides) codes for a 13,823 molecular weight polypeptide with a transit peptide of 53 amino acids and a mat ... | 1992 | 1542565 |
| pre-steady-state kinetics of the activation of rabbit skeletal muscle myosin light chain kinase by ca2+/calmodulin. | myosin light chain kinase is activated by ca2+/calmodulin. insights into the kinetic mechanism of this activation by ca2+/calmodulin have now been obtained using extrinsically labeled fluorescent calmodulin, a fluorescent peptide substrate, and a stopped-flow spectrophotofluorimeter. we employed spinach calmodulin labeled with the sulfhydryl-selective probe, 2-(4-maleimidoanilino)naphthalene-6-sulfonic acid, to measure changes in the fluorescence intensity of the 2-(4-maleimidoanilino)naphthalen ... | 1992 | 1544916 |
| enzyme supplementation, degradation and metabolism of three u-14c-labelled cell-wall substrates in the fowl. | an experimental model is described that was used for assessing in vivo effects in fowls of exogenous enzyme supplementation on the degradation of plant cell walls to metabolizable monosaccharide residues. it was based on tube-feeding u-14c-labelled cell-wall substrates, cellulose, spinach (spinacia oleracea) or festuca, with and without enzyme treatments, and monitoring recovery of 14c radioactivity in exhaled carbon dioxide and excreta in the following 8 h. normal digestion of cell-wall polysac ... | 1992 | 1547205 |
| rna editing in tobacco chloroplasts leads to the formation of a translatable psbl mrna by a c to u substitution within the initiation codon. | the psbl gene which codes for a 38 amino acid peptide of photosystem ii, together with the photosynthetic genes psbe and psbf, is contained in a conserved position of many species of higher plant plastomes. the alignment of the psbl nucleotide sequences from ten species shows strong conservation, which is indicative of a functional gene. the tobacco and spinach psbl genes have, however, an acg codon instead of the initiator atg codon observed in the homologous position of the other eight species ... | 1992 | 1547774 |
| molecular characterization of ferredoxin-nadp+ oxidoreductase in cyanobacteria: cloning and sequence of the peth gene of synechococcus sp. pcc 7002 and studies on the gene product. | the peth gene encoding ferredoxin-nadp+ oxidoreductase (fnr) was cloned and sequenced from the cyanobacterium synechococcus sp. pcc 7002. the deduced amino acid sequence of the fnr protein (402 amino acids) is approximately 110 amino acids longer at the n-terminus than fnr proteins which have been characterized from other cyanobacteria. n-terminal amino acid sequence analysis of the protein confirms the assigned translational start codon and shows that the initiator methionine is not removed. ma ... | 1992 | 1554697 |
| activities of two dissimilar thioredoxins from the cyanobacterium anabaena sp. strain pcc 7120. | thioredoxin is a small redox protein that functions as a reducing agent and modulator of enzyme activity. a gene for an unusual thioredoxin was previously isolated from the cyanobacterium anabaena sp. strain pcc 7120 and cloned and expressed in escherichia coli. however, the protein could not be detected in anabaena cells (j. alam, s. curtis, f. k. gleason, m. gerami-nejad, and j. a. fuchs, j. bacteriol. 171:162-171, 1989). polyclonal antibodies to the atypical thioredoxin were prepared, and the ... | 1992 | 1556078 |
| cloning and sequencing of a cdna encoding ascorbate peroxidase from arabidopsis thaliana. | a cdna clone encoding ascorbate peroxidase (ap, ec 1.11.1.11) was isolated from a phage lambda gt11 library of cdna from arabidopsis thaliana by immunoscreening with monoclonal antibodies against the enzyme, and then sequenced. the cdna insert hybridized to a 1.1 kb poly(a)+ rna from leaves of a. thaliana. genomic hybridization suggests that the cdna obtained here corresponds to a single-copy gene. the n-terminal amino acid sequence of arabidopsis ap was determined by protein sequencing of the i ... | 1992 | 1558944 |
| a gene homologous to chloroplast carbonic anhydrase (icfa) is essential to photosynthetic carbon dioxide fixation by synechococcus pcc7942. | to understand the co2-concentrating mechanism in cyanobacteria, a genomic dna fragment that complements a temperature-sensitive high-co2 (5%)-requiring mutant of synechococcus pcc7942 has been isolated. an open reading frame (orf272) encoding a polypeptide of 272 amino acids (mr, 30,184) was found within the genomic region located 20 kilobases downstream from the genes for ribulose-1,5-bisphosphate carboxylase/oxygenase (rbcls). insertion of a kanamycin-resistance gene cartridge within the orf27 ... | 1992 | 1584776 |
| immunochemical and immunohistochemical detection of s-100-like immunoreactivity in spinach tissues. | s-100 proteins represent a group of closely related acidic, calcium binding proteins originally isolated from the mammalian nervous system and later detected in non-neural cell types and in a wide variety of vertebrate and invertebrate species. the present study used immunochemical and immunohistochemical methods to extend the investigation of s-100 during phylogenesis to plant tissues. the presence of s-100-like immunoreactive material was detected in extracts of spinach (spinacia oleracea l.) ... | 1992 | 1588029 |
| electrostatic fields at the active site of ribulose-1,5-bisphosphate carboxylase. | a macroscopic approach has been employed to calculate the electrostatic potential field of nonactivated ribulose-1,5-bisphosphate carboxylase and of some complexes of the enzyme with activator and substrate. the overall electrostatic field of the l2-type enzyme from the photosynthetic bacterium rhodospirillum rubrum shows that the core of the dimer, consisting of the two c-terminal domains, has a predominantly positive potential. these domains provide the binding sites for the negatively charged ... | 1992 | 1603801 |
| occurrence of thermotolerant campylobacters in fresh vegetables sold at farmers' outdoor markets and supermarkets. | a total of 1564 fresh samples of 10 vegetable types from two different retail levels (533 samples from farmers' outdoor markets and 1031 samples from supermarkets) were surveyed for the occurrence of thermotolerant campylobacters. in samples from the outdoor markets, campylobacters were detected on six types of vegetables; the detection rates were spinach, 3.3; lettuce, 3.1; radish, 2.7; green onions, 2.5; parsley, 2.4; and potatoes, 1.6%. campylobacter jejuni was the predominant species (88%), ... | 1992 | 1611556 |
| type 1 ribosome-inactivating proteins depurinate plant 25s rrna without species specificity. | four different type 1 ribosome-inactivating proteins (rips) with rna n-glycosidase activity were tested for their ability to attack the large rrna of plant ribosomes derived from tobacco plants, as well as from the plant species from which the particular rip had been isolated. incubation of tobacco ribosomes with rips isolated from either phytolacca americana l. (pokeweed), dianthus barbatus l. (carnation), spinacia oleracea l. (spinach) or chenopodium amaranthicolor coste and reyn. (chenopodium ... | 1992 | 1620614 |
| ferredoxin and flavodoxin from the cyanobacterium synechocystis sp pcc 6803. | the unicellular cyanobacterium synechocystis sp pcc 6803 is capable of synthesizing two different photosystem-i electron acceptors, ferredoxin and flavodoxin. under normal growth conditions a [2fe-2s] ferredoxin was recovered and purified to homogeneity. the complete amino-acid sequence of this protein was established. the isoelectric point (pi = 3.48), midpoint redox potential (em = -0.412 v) and stability under denaturing conditions were also determined. this ferredoxin exhibits an unusual ele ... | 1992 | 1633177 |
| resonance raman and magnetic circular dichroism studies of reduced [2fe-2s] proteins. | the structural and electronic properties of the [2fe-2s] clusters in reduced putidaredoxin, spinacea oleracea ferredoxin, and clostridium pasteurianum [2fe-2s] ferredoxin have been investigated by resonance raman and variable temperature magnetic circular dichroism spectroscopies. both techniques are shown to provide diagnostic fingerprints for identifying [2fe-2s]+ clusters in more complex multicomponent metalloenzymes. the fe-s stretching modes of oxidized and reduced putidaredoxin are assigne ... | 1992 | 1639790 |
| isolation and sequencing of the cdna coding for spinach 10-formyltetrahydrofolate synthetase. comparisons with the yeast, mammalian, and bacterial proteins. | the one-carbon metabolism enzymes 10-formyltetrahydrofolate synthetase (ec 6.3.4.3), 5,10-methenyltetrahydrofolate cyclohydrolase (ec 3.5.4.9), and 5,10-methylenetetrahydrofolate dehydrogenase (ec 1.5.1.5) can be found on a single trifunctional protein in the eukaryotes examined. the one exception is in spinach leaves where 10-formyltetrahydrofolate synthetase is monofunctional (nour, j. m., and rabinowitz, j. c. (1991) j. biol. chem. 266, 18363-18369). in the prokaryotes examined, 10-formyltetr ... | 1992 | 1644815 |
| complete cloning of the chloroplast genome of safflower in lambda embl3 and mapping of 23s and 16s rrna genes. | a recombinant dna library was constructed from partial bamhi or mboi digests of safflower (carthamus tinctorius l.) chloroplast dna, in the bamhi site of lambda embl3. seventeen lambda recombinants, selected by chromosome walking, were found to contain overlapping fragments of the entire chloroplast genome. these clones were mapped using single and double digests of bamhi, ecori and hindiii. cdnas synthesized from isolated 16s and 23s chloroplast rrnas were used to map the ribosomal rna genes re ... | 1991 | 1646953 |
| specificity of leaf mitochondrial and chloroplast processing systems for nuclear-encoded precursor proteins. | the specificity of the mitochondrial and chloroplast processing enzymes for the nuclear-encoded precursor proteins was investigated. mitochondrial precursor proteins of the nicotiana plumbaginifolia and the neurospora crassa beta subunits of f1-atpase and the neurospora rieske fes precursor protein were processed to the correct mature size by matrix extracts isolated from spinach leaves, yeast, rat liver and beef heart. the mitochondrial extracts failed to process chloroplast precursor proteins ... | 1991 | 1654154 |
| the effect of high hydrostatic pressure on the modulation of regulatory enzymes from spinach chloroplasts. | high hydrostatic pressure enhanced the specific activity of regulatory enzymes of the benson-calvin cycle (fructose-1,6-bisphosphatase, glyceraldehyde-3-p dehydrogenase, phosphoribulokinase) which are modulated by the ferredoxin-thioredoxin system. high activity of chloroplast fructose-1,6-bisphosphatase required dithiothreitol, fructose 1,6-bisphosphate, and ca2+. at 100 bar the a0.5 for fructose 1,6-bisphosphate (0.3 mm) was lower than that at 1 bar (1.5 mm), whereas similar variations of pres ... | 1991 | 1657939 |
| dccd binds to cytochrome b6 of a cytochrome bf complex isolated from spinach chloroplasts and inhibits proton translocation. | radiolabeled n,n'-dicyclohexylcarbodiimide (dccd) was bound selectively in a time- and concentration-dependent manner to cytochrome b6 of an enzymatically active cytochrome bf complex isolated from spinach chloroplasts. maximum labeling of cytochrome b6 was observed with 30 nmol dccd per nmol cytochrome b6 in the cytochrome bf complex incubated for 30-60 min at 12 degrees c. after incubation of the cytochrome bf complex with dccd under these conditions, the rate of proton ejection in the complex ... | 1991 | 1659325 |
| ubiquitination of endogenous calmodulin in rabbit tissue extracts. | previously we were able to show that purified calmodulins from vertebrates, plants (spinach) and the mold neurospora crassa can be covalently conjugated to ubiquitin in a ca(2+)-dependent manner. it was therefore pertinent to answer the question if a tissue extract contains all the components necessary for the endogenous synthesis of ubiquityl calmodulin (ucam). therefore [125i]ubiquitin, atp/mg2+ and ca2+ were added to tissue extracts enriched by a single ion exchange step. in such extracts of ... | 1991 | 1661685 |
| auxin-binding protein--antibodies and genes. | of several auxin-binding systems that have been characterised the auxin-binding protein (abp) of maize coleoptile membranes is the best candidate for a true auxin receptor. abp, which exists as a homodimer of 22 x 10(3) m(r) glycosylated subunits, has been purified, and monoclonal and polyclonal antibodies raised against it. electrophysiological studies with antibodies indicated the presence of a functional population of auxin receptors on the exterior face of the plasmalemma; electrophysiologic ... | 1991 | 1668837 |
| reactivation of the chloroplast cf1-atpase beta subunit by trace amounts of the cf1 alpha subunit suggests a chaperonin-like activity for cf1 alpha. | incubation of tobacco and lettuce thylakoids with 2 m licl in the presence of mgatp removes the beta subunit from their cf1-atpase (cf1 beta) together with varying amounts of the cf1 alpha subunit (cf1 alpha). these 2 m licl extracts, as with the one obtained from spinach thylakoids (avital, s., and gromet-elhanan, z. (1991) j. biol. chem. 266, 7067-7072), could form active hybrid atpases when reconstituted into inactive beta-less rhodospirillum rubrum chromatophores. pure cf1 beta fractions tha ... | 1991 | 1673460 |
| [nucleic acid components in carbohydrate-rich food]. | the content of nucleic acid components in numerous foods, especially carbohydrate-rich ones, has been investigated. the data obtained for bases (purines and pyrimidines) were calculated as nucleic-acid equivalents (rna or dna); the imp content was calculated from the measured content of hypoxanthine. not only did cultivated plants such as cereals and pulses show a high rna-equivalent content but also vegetables such as spinach, leek, broccoli, chinese cabbage and cauliflower. we found the same r ... | 1990 | 1689090 |
| organochlorine pesticide residues in different indian cereals, pulses, spices, vegetables, fruits, milk, butter, deshi ghee, and edible oils. | a total of 244 samples of cereals (wheat flour, rice, and maize), pulses (arhar, moong, gram, lentil, and black gram), spices (turmeric, chili, coriander, and black pepper), vegetables (potato, onion, spinach, cabbage, brinjal, and tomato), fruits (mango, guava, apple, and grape), milk, butter, deshi ghee, and edible oils (vegetable, mustard, groundnut, and sesame) collected from different cities of northern province (utter pradesh) were analyzed by gas liquid chromatography for the presence of ... | 1990 | 1698760 |
| the chloroplast gene for ribosomal protein cl23 is functional in tobacco. | chloroplast rpl23 loci potentially coding for a polypeptide homologous to the e. coli l23 ribosomal protein are frame-shifted in spinach and several other plants, indicating that these loci are pseudogenes. in tobacco, rpl23 constitutes a continuous open reading frame of 93 codons and its transcript initiates at least 66 bp upstream from the initiation codon. the n-terminal amino acid sequence of a 13 kda protein from the 50 s subunit of tobacco chloroplast ribosomes matches that derived from th ... | 1991 | 1707833 |
| isolation, characterization and sequence analysis of a full-length cdna clone encoding acetohydroxy acid reductoisomerase from spinach chloroplasts. | acetohydroxy acid reductoisomerase (ahri), the second enzyme in the parallel isoleucine/valine-biosynthetic pathway, catalyses an unusual two-step reaction in which the substrate, either 2-acetolactate or 2-aceto-2-hydroxybutyrate, is converted via an alkyl migration and an nadph-dependent reduction to give 2,3-dihydroxy-3-methylbutyrate or 2,3-dihydroxy-3-methylvalerate respectively. we have isolated and characterized a full-length cdna from a lambda gt11 spinach library encoding the complete a ... | 1991 | 1713446 |
| monoclonal antibodies toward scallop (patinopecten yessoensis) testis and wheat germ calmodulins. | a monoclonal antibody (im7) toward scallop testis calmodulin and another one (pbe2) toward wheat germ calmodulin were produced. ca2+ was required for im7 to react with scallop calmodulin. im7 reacted with the c-terminal region (asp78-lys148) of the calmodulin. as observed on competitive elisa, im7 reacted with chicken calmodulin, but not with euglena gracilis or wheat calmodulin, troponin c, myosin light chains, or parvalbumin. it is assumed that the cluster of thr143, thr146, and ser147 in the ... | 1991 | 1714441 |
| isolation and characterization of different forms of thioredoxins from the green alga acetabularia mediterranea: identification of an nadp/thioredoxin system in the extrachloroplastic fraction. | a procedure has been developed for the simultaneous purification to apparent homogeneity of chloroplast thioredoxins f and m, and nonchloroplast thioredoxin h, from the green alga acetabularia mediterranea. in the chloroplast fraction, three thioredoxins were isolated: one f type thioredoxin (mr 13.4 kda) and two m type thioredoxin forms (mr of 12.9 and 13.8 kda). a western blot analysis of crude and purified chloroplast thioredoxin preparations revealed that acetabularia thioredoxin m was immun ... | 1992 | 1727634 |
| bone composition and histology of young growing rats fed diets of varied calcium bioavailability: spinach, nonfat dry milk, or calcium carbonate added to casein. | bone composition and histology were evaluated in young growing rats fed nutritionally complete but calcium-restricted (0.15%) diets in which calcium was derived from spinach, nonfat dry milk (nfdm), or caco3 added to casein. groups of male weanling rats were pair-fed for 28 d. a 0.5% calcium casein-based diet group fed ad libitum was included to provide a comparison of normal bone structure and composition. bone growth and bone ash were depressed in spinach-fed rats. total bone tibia calcium in ... | 1992 | 1729463 |
| a plant homologue to mammalian brain 14-3-3 protein and protein kinase c inhibitor. | we have isolated cdna clones of spinacea oleracea l. and oenothera hookeri of 930 and 1017 base pairs, respectively. the open reading frame deduced from the oenothera sequence codes for a protein of a calculated molecular mass of 29,200. the primary amino acid sequence exhibits a very high degree (88%) of homology to the 14-3-3 protein from bovine brain, and protein kinase c inhibitor from sheep brain. subsequently the plant protein was partially purified from leaf extract. the partially purifie ... | 1992 | 1733782 |
| the sequence of squash nadh:nitrate reductase and its relationship to the sequences of other flavoprotein oxidoreductases. a family of flavoprotein pyridine nucleotide cytochrome reductases. | nucleotide sequences were determined for cdna clones for squash nadh:nitrate oxidoreductase (ec 1.6.6.1), which is one of the most completely characterized forms of this higher plant enzyme. an open reading frame of 2754 nucleotides began at the first atg. the deduced amino acid sequence contains 918 residues, with a predicted mr = 103,376. the amino acid sequence is very similar to sequences deduced for other higher plant nitrate reductases. the squash sequence has significant similarity to the ... | 1991 | 1748631 |
| [obtention with polymerase chain reaction (pcr) of gene rbcl in the scrophulariaceae holoparasite lathraea clandestina l. comparison with autotroph digitalis purpurea l. and melampyrum pratense l]. | amyloplastid dna was extracted from the scrophulariaceae holoparasite lathraea clandestina l. and then purified. an rbcl gene amplification was performed using polymerase chain reaction. two regions of well conserved sequences in tobacco, spinach and maize rbcl gene have been used as primers. pcr yields a sequence of about 1,230 base pairs, almost nine tenths of the rbcl coding region. identical results were obtained with plastid dnas from tobacco and two other species of scrophulariaceae: the n ... | 1991 | 1756411 |
| the nuclear:organelle distribution of chloroplast ribosomal proteins genes. features of a cdna clone encoding the cytoplasmic precursor of l11. | the majority of chloroplast ribosomal proteins are encoded in the nuclear genome. in order to characterize these proteins through their mrna, we have previously constructed a spinach cdna expression library and raised antisera to several spinach chloroplast ribosomal proteins. here we describe the immuno isolation of cdna clones encoding protein l11 and its chloroplast-targeting presequence. the cytoplasmic precursor form of l11 is 224 amino acid residues long (mr 23,662); the mature l11 and the ... | 1991 | 1764529 |
| [cloning and sequencing of spinach chloroplast dna fragments with promoter activities in e. coli]. | sau3a partially digested spinach cdna fragments were cloned in bgiii restriction site of a e. coli promoter probing vector pga46. the cloned fragments with promoter activities in e. coli were found by the abilities of recovering tetracycling resistance of their host cells. the promoter functions of the two fragments and their different strengths are deciphered by analyzing their dna sequences. | 1991 | 1768458 |
| use of digoxigenin-labelled probes for detection and host-range studies of tomato yellow leaf curl geminivirus. | we studied the host range of tomato yellow leaf curl virus (tylcv) in some agronomically important tomato species. transmission tests with the natural vector bemisia tabaci from tomato to sweet pepper, eggplant, cucumber, melon, zucchini and spinach showed that these species did not develop symptoms and did not support viral replication. these species therefore do not constitutive a reservoir of the virus and can be cultivated as alternatives to tomato in the most affected areas. for host-range ... | 1991 | 1796214 |
| binding of the recombinant proteinase inhibitor eglin c from leech hirudo medicinalis to serine (pro)enzymes: a comparative thermodynamic study. | the binding of the recombinant proteinase inhibitor eglin c from the leech hirudo medicinalis to serine (pro)enzymes belonging to the chymotrypsin and subtilisin families has been investigated from the thermodynamic viewpoint, between ph 4.5 and 9.5 and from 10 degrees c to 40 degrees c. the affinity of eglin c for the serine (pro)enzymes considered shows the following trend: leu-proteinase [the leucine specific serine proteinase from spinach (spinacia oleracea l.) leaves] greater than human leu ... | 1991 | 1799460 |
| extraction and purification of the beta subunit and an active alpha beta-core complex from the spinach chloroplast cfof1-atp synthase. | incubation of rhodospirillum rubrum chromatophores with 2 m licl in the presence of mgatp has been shown to remove their f1 beta subunit leaving inactive but fully reconstitutable beta-less chromatophores (gromet-elhanan, z., and khanashvili, d., (1986) methods enzymol, 126, 528-538). a similar treatment of thoroughly washed spinach thylakoids has now been shown to release the cf1 beta subunit (cf1 beta) together with a complex containing equal amounts of cf1 alpha and cf1 beta (cf1 (alpha beta] ... | 1991 | 1826683 |
| expression of the two isoforms of spinach ribulose 1,5-bisphosphate carboxylase activase and essentiality of the conserved lysine in the consensus nucleotide-binding domain. | the two isoforms of ribulose 1,2-bisphosphate carboxylase activase (rbu-p2 carboxylase) from spinach (spinacea oleracea l.) were individually purified from escherichia coli transformed with expression vectors for the appropriate cdnas. both isoforms catalyzed activation of rbu-p2 carboxylase (ribulose 1,5-bisphosphate carboxylase/oxygenase, ec 4.1.1.39) and atp hydrolysis. the kinetics of the two isoforms with respect to atp concentration were different, in that the 45-kda polypeptide exhibited ... | 1991 | 1827441 |
| subunit delta of chloroplast f0f1-atpase and oscp of mitochondrial f0f1-atpase: a comparison by cd-spectroscopy. | cd spectra have been recorded with subunit delta from chloroplast cf0cf1 and with oscp from mitochondrial mf0mf1. these subunits are supposed to act similarly at the interface between proton transport through the f0-portion and atp-synthesis in the f1-portion of their respective f0f1-atpase. evaluation of the data for both proteins revealed a very high alpha-helix content of approximately 85% and practically no beta-sheets. despite their low homology on the primary structure level (23% identity) ... | 1991 | 1836327 |
| ferredoxins from two sulfonylurea herbicide monooxygenase systems in streptomyces griseolus. | we have purified and characterized two ferredoxins, designated fd-1 and fd-2, from the soluble protein fraction of sulfonylurea herbicide induced streptomyces griseolus. these cells have previously been shown to contain two inducible cytochromes p-450, p-450su1 (cyp105a1) and p-450su2 (cyp105b1), responsible for herbicide metabolism [o'keefe, d. p., romesser, j. a., & leto, k. j. (1988) arch. microbiol. 149, 406-412]. although fd-2 is more effective, either ferredoxin can restore sulfonylurea mo ... | 1991 | 1846297 |
| electron spin echo envelope modulation spectroscopy supports the suggested coordination of two histidine ligands to the rieske fe-s centers of the cytochrome b6f complex of spinach and the cytochrome bc1 complexes of rhodospirillum rubrum, rhodobacter sphaeroides r-26, and bovine heart mitochondria. | electron spin echo envelope modulation (eseem) experiments performed on the rieske fe-s clusters of the cytochrome b6f complex of spinach chloroplasts and of the cytochrome bc1 complexes of rhodospirillum rubrum, rhodobacter sphaeroides r-26, and bovine heart mitochondria show modulation components resulting from two distinct classes of 14n ligands. at the g = 1.92 region of the rieske epr spectrum of the cytochrome b6f complex, the measured hyperfine couplings for the two classes of coupled nit ... | 1991 | 1847076 |
| expression in escherichia coli of c-type cytochrome genes from rhodopseudomonas viridis. | the genes coding for the photosynthetic reaction center cytochrome c subunit (pufc) and the soluble cytochrome c2 (cyca) from the purple non-sulfur bacterium rhodopseudomonas viridis were expressed in escherichia coli. biosynthesis of the reaction center cytochrome without a signal peptide resulted in the formation of inclusion bodies in the cytoplasm amounting to 14% of the total cellular protein. a series of plasmids coding for the cytochrome subunit with varying n-terminal signal peptides was ... | 1991 | 1848106 |
| mutation of a negatively charged amino acid in thioredoxin modifies its reactivity with chloroplastic enzymes. | a new over-expression system has been set up for escherichia coli thioredoxin, yielding 55 mg purified protein/10 g fresh cells. this system has been used to produce thioredoxin modified by site-directed mutagenesis. taking advantage of the structural and enzymatic similarity between e. coli and spinach m-type thioredoxin, asp61 of e. coli thioredoxin has been changed into asn in order to investigate the impact of the suppression of a charged residue on the interaction of thioredoxin with target ... | 1991 | 1848815 |
| chloroplast dna topoisomerase i from cauliflower. | an atp-independent dna topoisomerase has been isolated from chloroplasts of cauliflower leaves (brassica oleracea var. botrytis) through deae-cellulose, af-blue toyopearl, and hydroxyapatite column chromatography. the sedimentation coefficient and stokes radius of this enzyme are 3.6s and 3.6 nm, respectively, and the molecular weight of native enzyme is estimated to be 54,000. this enzyme changes the linking number in steps of one. the enzyme activity is stimulated by mgcl2, and this enzyme sho ... | 1991 | 1849883 |
| expression of spinach glycolate oxidase in saccharomyces cerevisiae: purification and characterization. | glycolate oxidase from spinach has been expressed in saccharomyces cerevisiae. the active enzyme was purified to near-homogeneity (purification factor approximately 1400-fold) by means of hydroxyapatite and anion-exchange chromatography. the purified glycolate oxidase is nonfluorescent and has absorbance peaks at 448 (epsilon = 9200 m-1 cm-1) and 346 nm in 0.1 m phosphate buffer, ph 8.3. the large bathochromic shift of the near-uv band indicates that the n(3) position is deprotonated at ph 8.3. ... | 1991 | 1850628 |
| thioredoxin activation of phosphoribulokinase in a chloroplast multi-enzyme complex. | the activation process of spinach phosphoribulokinase by thioredoxin f has been studied with the enzyme in a free, isolated state, or integrated in a multi-enzyme complex. the time periods required for enzyme activation are always smaller and the maximal enzyme velocities are always greater when chloroplast phosphoribulokinase is included in the multi-enzyme complex than when it is in the isolated state. comparative kinetic studies show that phosphoribulokinase extracted from the complex behaves ... | 1991 | 1851485 |
| a protein in the oxygen-evolving complex in the chloroplast is associated with symptom expression on tobacco leaves infected with cucumber mosaic virus strain y. | to elucidate the molecular basis of symptom expression in virus-infected plants, the changes in proteins between tobacco, nicotiana tabacum cv. ky57, leaves inoculated with cucumber mosaic virus strain y [cmv(y)] and strain o [cmv(o)], were compared by 2-dimensional (2-d) gel electrophoresis. the appearance of chlorotic spots in cmv(y)-inoculated tobacco leaves accompanied an increase of 3 polypeptides and a decrease in 6 polypeptides, as compared with those in the cmv(o)-inoculated tobacco whic ... | 1991 | 1868202 |
| isolation of the spinach nitrite reductase gene promoter which confers nitrate inducibility on gus gene expression in transgenic tobacco. | nitrite reductase is the second enzyme in the nitrate assimilatory pathway. the transcription of this gene is regulated by nitrate as well as a variety of other environmental and developmental factors. genomic clones containing the entire nitrite reductase gene have been isolated from a spinach genomic library and sequenced. the sequence is identical in the transcribed region to a previously isolated spinach nir cdna clone (back et al., 1988) except for the presence of three introns. the analysi ... | 1991 | 1868226 |
| characterization of an escherichia coli gene encoding betaine aldehyde dehydrogenase (badh): structural similarity to mammalian aldhs and a plant badh. | an open reading frame of 1476 nucleotides, cloned from a region of the escherichia coli genome encoding betaine biosynthesis functions, was shown to encode a betaine aldehyde dehydrogenase (badh; ec 1.2.1.8). either of two adjacent codons (5'-gtgatg) could function as a start codon, producing a presumptive polypeptide of 491 or 490 amino acids. the deduced primary structure of the e. coli badh showed 39-43% positional identity, over its entire length, to aldehyde dehydrogenases (aldh: ec 1.2.1.3 ... | 1991 | 1879697 |
| three-dimensional structure of cu,zn-superoxide dismutase from spinach at 2.0 a resolution. | the three-dimensional structure of cu,zn-superoxide dismutase from spinach leaves has been determined by x-ray crystal structure analysis. the atomic coordinates were refined at 2.0 a resolution using the hendrickson and konnert program for stereochemically restrained refinement against structure factors, which allowed the use of non-crystallographic symmetry. the crystallographic residual error for the refined model was 24.9%, with a root mean square deviation of 0.03 a from the ideal bond leng ... | 1991 | 1880134 |
| expression of a cdna clone encoding the haem-binding domain of chlorella nitrate reductase. | a partial cdna clone coding for the haem-binding domain of nadh:nitrate reductase (ec 1.6.6.1) (nr) from the unicellular green alga chlorella vulgaris has been isolated, sequenced and expressed. a 1.2 kb cdna (pcvnr1) was isolated from a lambda gt11 expression library produced from polyadenylated rna extracted from nitrate-grown chlorella cells. pcvnr1 hybridized to a 3.5 kb mrna transcript that was nitrate-inducible and absent from ammonium-grown cells. the entire sequence of pcvnr1 was obtaine ... | 1991 | 1883330 |
| conservation and evolution of the nucleus-encoded and chloroplast-specific ribosomal proteins in pea and spinach. | two cdna clones have been isolated from a lambda g11 cdna library constructed with poly(a)+ mrnas prepared from spinach seedlings. these nuclear cdnas encode chloroplast (cp) ribosomal (r) proteins designated l24 and l40. these r-proteins have been identified in the cp 50s r-subunit by immunoblot analysis, amino acid (aa) composition and n-terminal aa sequencing. the l24 r-protein contains a central eubacterial homologous core with the n- and c-terminal polypeptide extensions. the l40 r-protein ... | 1991 | 1889743 |
| plant thioredoxin h: an animal-like thioredoxin occurring in multiple cell compartments. | thioredoxin h has been purified to electrophoretic homogeneity from spinach roots using a procedure devised for leaves. the root thioredoxin (h2 form) differed from chloroplast and animal thioredoxins in showing an atypical active site (cys-ala-pro-cys) but otherwise resembled animal thioredoxin in structure. sequence data for a total of 72 residues of spinach root thioredoxin h2 (about 69% of the primary structure) showed 43-44% identity with rabbit and rat thioredoxin. analysis of cell fractio ... | 1991 | 1897989 |
| the relative catalytic specificities of the large subunit core of synechococcus ribulose bisphosphate carboxylase/oxygenase. | the relative specificities of the carboxylase and oxygenase reactions catalyzed by the recombinant large subunit core (l8) of synechococcus ribulose 1,5-bisphosphate carboxylase have been determined. the l8 core still retained the ability to catalyze both reactions but at a much reduced turnover rate, about 0.6% of the holoenzyme. the fate of ribulose 1,5-bisphosphate during carboxylation and oxygenation by l8 was compared with the synechococcus holoenzyme (reconstituted from l8 and recombinant ... | 1991 | 1902218 |
| pyruvate is a by-product of catalysis by ribulosebisphosphate carboxylase/oxygenase. | pyruvate is a minor product of the reaction catalyzed by ribulosebisphosphate carboxylase/oxygenase from spinach leaves. labeled pyruvate was detected, in addition to the major labeled product, 3-phosphoglycerate, when 14co2 was the substrate. pyruvate production was also measured spectrophotometrically in the presence of lactate dehydrogenase and nadh. the km for co2 of the pyruvate-producing activity was 12.5 microm, similar to the co2 affinity of the 3-phosphoglycerate-producing activity. no ... | 1991 | 1903385 |
| evolutionary relationships among eubacteria, cyanobacteria, and chloroplasts: evidence from the rpoc1 gene of anabaena sp. strain pcc 7120. | rna polymerases of cyanobacteria contain a novel core subunit, gamma, which is absent from the rna polymerases of other eubacteria. the genes encoding the three largest subunits of rna polymerase, including gamma, have been isolated from the cyanobacterium anabaena sp. strain pcc 7120. the genes are linked in the order rpob, rpoc1, rpoc2 and encode the beta, gamma, and beta' subunits, respectively. these genes are analogous to the rpobc operon of escherichia coli, but the functions of rpoc have ... | 1991 | 1904436 |
| crystal structure of activated ribulose-1,5-bisphosphate carboxylase complexed with its substrate, ribulose-1,5-bisphosphate. | the three-dimensional structure of the complex of ribulose-1,5-bisphosphate carboxylase from rhodospirillum rubrum, co2, mg2+, and ribulose bisphosphate has been determined with x-ray crystallographic methods to 2.6-a resolution. ribulose-1,5-bisphosphate binds across the active site with the two phosphate groups in the two phosphate binding sites of the beta/alpha barrel. the oxygen atoms of the carbamate and the side chain of asp-193 provide the protein ligands to the bound mg2+ ion. the c2 an ... | 1991 | 1905726 |
| laser flash photolysis studies of the kinetics of reduction of ferredoxins and ferredoxin-nadp+ reductases from anabaena pcc 7119 and spinach: electrostatic effects on intracomplex electron transfer. | the influence of electrostatic forces on the formation of, and electron transfer within, transient complexes between redox proteins was examined by comparing ionic strength effects on the kinetics of the electron transfer reaction between reduced ferredoxins (fd) and oxidized ferredoxin-nadp+ reductases (fnr) from anabaena and from spinach, using laser flash photolysis techniques. with the anabaena proteins, direct reduction by laser-generated flavin semiquinone of the fnr component was inhibite ... | 1991 | 1910302 |
| interaction of ferredoxin-nadp+ reductase from anabaena with its substrates. | the interaction of ferredoxin-nadp+ reductase from the cyanobacterium anabaena variabilis with its substrates, nadp+ and ferredoxin, has been studied by difference absorption spectroscopy. several structural analogs of nadp+ have been shown to form complexes the stabilities of which are strongly dependent on the ionic strength of the medium. in most cases the binding energy of these complexes and their difference absorption spectra are similar to those reported for the spinach enzyme. however, n ... | 1991 | 1910307 |
| primary structure of the assimilatory-type sulfite reductase from desulfovibrio vulgaris (hildenborough): cloning and nucleotide sequence of the reductase gene. | the nucleotide sequence encoding the structural gene (651 bp) and flanking regions for the assimilatory-type sulfite reductase from the sulfate-reducing bacterium desulfovibrio vulgaris (hildenborough) was determined after cloning a 1.4 kb hindiii/sali genomic fragment possessing the gene into bluescript pbs(+)ks. the primary structure of the protein was deduced, and the molecular mass of the apoprotein was estimated as 24 kda. the amino acid sequence of the polypeptide shows some similarities a ... | 1991 | 1911781 |
| probing the role of lysine 116 and lysine 244 in the spinach ferredoxin-nadp+ reductase by site-directed mutagenesis. | two mutants of the spinach ferredoxin-nadp+ reductase (fnr) were constructed, expressed by using a heterologous expression system previously described (aliverti, a., jansen, t., zanetti, g., ronchi, s., herrmann, r. g., and curti, b. (1990) eur. j. biochem. 191, 551-555), and purified to homogeneity. the mutant enzymes fnr-lys116gln and fnr-lys244gln were similar to the wild-type enzyme in the physicochemical properties measured; however, both enzymes showed a lower activity. steady-state kineti ... | 1991 | 1917920 |
| isolation, characterization, and structural organization of 10-formyltetrahydrofolate synthetase from spinach leaves. | one-carbon metabolism mediated by folate coenzymes plays an essential role in several major cellular processes. in the prokaryotes studied, three folate-dependent enzymes, 10-formyltetrahydrofolate synthetase (ec 6.3.4.3), 5,10-methenyltetrahydrofolate cyclohydrolase (ec 3.5.4.9), and 5,10-methylenetetrahydrofolate dehydrogenase (ec 1.5.1.5) generally exist as monofunctional or bifunctional proteins, whereas in eukaryotes the three activities are present on one polypeptide. the structural organi ... | 1991 | 1917961 |
| resonance raman spectra of plastocyanin and pseudoazurin: evidence for conserved cysteine ligand conformations in cupredoxins (blue copper proteins). | new resonance raman (rr) spectra at 15 k are reported for poplar (populus nigra) and oleander (oleander nerium) plastocyanins and for alcaligenes faecalis pseudoazurin. the spectra are compared with those of other blue copper proteins (cupredoxins). in all cases, nine or more vibrational modes between 330 and 460 cm-1 can be assigned to a coupling of the cu-s(cys) stretch with cys ligand deformations. the fact that these vibrations occur at a relatively constant set of frequencies is testimony t ... | 1991 | 1932014 |
| molecular cloning and targeted mutagenesis of the gene psaf encoding subunit iii of photosystem i from the cyanobacterium synechocystis sp. pcc 6803. | photosystem i is one of the two multisubunit pigment-protein complexes in the thylakoid membranes of cyanobacteria. subunit iii of photosystem i complex was isolated from a mutant of the cyanonbacterium synechocystis sp pcc 6803, which lacks subunit ii. the sequence of its nh2-terminal residues was determined and corresponding oligonucleotide probes were used to isolate the gene encoding this subunit. the gene, designated as psaf, codes for a mature protein of 15705 da that is synthesized with a ... | 1991 | 1939076 |
| spinach glycolate oxidase and yeast flavocytochrome b2 are structurally homologous and evolutionarily related enzymes with distinctly different function and flavin mononucleotide binding. | a comparison of the three-dimensional structures of the flavin mononucleotide (fmn)-dependent enzymes glycolate oxidase, flavocytochrome b2, and trimethylamine dehydrogenase is presented. their flavin-binding domains all have the same structural motif, the 8-fold beta/alpha-barrel domain, which is also present in a large number of other enzymes. fmn is bound in a similar fashion in all three enzymes. the binding site is at the carboxyl-terminal end of the eight beta-strands of the barrel where t ... | 1991 | 1993693 |
| primary structures of the precursor and mature forms of stearoyl-acyl carrier protein desaturase from safflower embryos and requirement of ferredoxin for enzyme activity. | stearoyl-acyl carrier protein (acp) desaturase (ec 1.14.99.6) catalyzes the principal conversion of saturated fatty acids to unsaturated fatty acids in the synthesis of vegetable oils. stearoyl-acp desaturase was purified from developing embryos of safflower seed, and extensive amino acid sequence was determined. the amino acid sequence was used in conjunction with polymerase chain reactions to clone a full-length cdna. the primary structure of the protein, as deduced from the nucleotide sequenc ... | 1991 | 2006194 |
| bioavailability of food folates and evaluation of food matrix effects with a rat bioassay. | folate bioavailability of beef liver, lima beans, peas, spinach, mushrooms, collards, orange juice and wheat germ was estimated with a protocol of folate depletion-repletion using growth and liver, serum and erythrocyte folate of weanling male rats. diets with 125, 250 and 375 micrograms folic acid/kg were standards. individual foods were incorporated into a folate-free amino acid-based diet alone (250 micrograms folate/kg diet from food) or mixed with folic acid (125 micrograms folate from food ... | 1991 | 2007897 |
| primary structure of a cerulenin-binding beta-ketoacyl-[acyl carrier protein] synthase from barley chloroplasts. | the radioactively labeled beta-ketoacyl thioester synthase inhibitor [3h] cerulenin was used to tag three dimeric barely chloroplast proteins (alpha alpha, alpha beta, and beta beta) from the stromal fraction. oligonucleotides corresponding to amino acid sequences obtained from the purified proteins were used to generate with the polymerase chain reaction a probe for cdnas encoding the beta subunit. cdna sequencing revealed an open reading frame for 462 residues comprising the mature protein and ... | 1991 | 2034657 |
| characterization and primary structure of a second thioredoxin from the green alga, chlamydomonas reinhardtii. | a second thioredoxin, ch1, distinct from the one recently reported [decottignies, p., schmitter, j.m., jacquot, j. p., dutka, s., picaud, a. & gadal, p. (1990) arch, biochem. biophys. 280, 112-121] has been purified from the green alga, chlamydomonas reinhardtii, and its functional and structural properties investigated. its activity in various enzymatic assays has been compared with the activities of different plant thioredoxins (ch2 from c. reinhardtii and spinach m and f). ch1 cannot serve as ... | 1991 | 2040309 |
| reconstitution of mature plastocyanin from precursor apo-plastocyanin expressed in escherichia coli. | the precursor plastocyanin from silene pratensis (white campion) has been expressed in escherichia coli. the precursor protein was accumulated in insoluble aggregates and partially purified as an apo-protein. the purified precursor apo-plastocyanin was processed to the mature apo-plastocyanin by chloroplast extracts. n-terminal amino-acid sequencing indicated that the processed protein was identical to the n-terminal amino-acid residues of mature plastocyanin that was deduced from the nucleotide ... | 1991 | 2049372 |
| hypothesis for the evolutionary origin of the chloroplast ribosomal protein l21 of spinach. | a full size cdna clone encoding the chloroplast ribosomal protein l21 from spinach is presented. the identity of the clone and the location of the transit peptide processing site were determined by comparison with the n-terminal amino acid sequence of the spinach chloroplast protein cs-l7 previously identified. l21 r-protein sequences from spinach, marchantia polymorpha and escherichia coli are compared. quite surprisingly, the data do not suggest that the rpl21 nuclear gene from spinach was der ... | 1990 | 2076556 |
| a ferredoxin-type iron-sulfur protein gene, frx b, is expressed in the chloroplasts of tobacco and spinach. | previously, a ferredoxin-type iron-sulfur protein, frx b protein, was identified in a high-salt extract of the purified thylakoid membrane of chlamydomonas reinhardtii, a unicellular green alga. polyclonal antibody was raised against a synthetic pentadecameric peptide with an amino acid sequence corresponding to the highly conserved region of the putative frx b proteins of 3 land plants. in this report, protein(s) reacting strongly and specifically with this antibody was detected in the equivale ... | 1990 | 2103463 |
| characterization of a ferredoxin:nadp+ oxidoreductase from a nonphotosynthetic plant tissue. | a flavoprotein with properties similar to those of ferredoxin:nadp+ oxidoreductases found in the leaves of higher plants has been purified to apparent homogeneity from bean sprouts, a nonphotosynthetic plant tissue. the absorbance and circular dichroism spectra of the bean sprout protein are similar to those of spinach leaf ferredoxin:nadp+ oxidoreductase and an antibody raised against the spinach enzyme recognized the bean sprout enzyme. the bean sprout enzyme catalyzed ferredoxin-dependent ele ... | 1990 | 2105079 |
| hsp70 proteins, similar to escherichia coli dnak, in chloroplasts and mitochondria of euglena gracilis. | the heat-shock response of euglena gracilis was studied by pulse-labeling cells with [35s]sulfate at both the normal growth temperature (21 degrees c) and an elevated temperature (36 degrees c). analysis of the labeled proteins by polyacrylamide gel electrophoresis indicated that the rate of synthesis of at least 3 major and 15 minor polypeptides increased in cells grown at the higher temperature. three of the proteins appear to be immunologically related to the ubiquitous approximately 70-kda h ... | 1990 | 2106681 |
| primary structure of a 7fe ferredoxin from streptomyces griseus. | the complete primary structure of a streptomyces griseus (atcc 13273) 7fe ferredoxin, which can couple electron transfer between spinach ferredoxin reductase and s. griseus cytochrome p-450soy for nadph-dependent substrate oxidation, has been determined by edman degradation of the whole protein and peptides derived by staphylococcus aureus v8 proteinase and trypsin digestion. the protein consists of 105 amino acids and has a calculated molecular weight, including seven irons and eight sulfurs, o ... | 1990 | 2106913 |
| spinach carbonic anhydrase primary structure deduced from the sequence of a cdna clone. | a cdna clone 1,156 base pairs in length was selected by screening a lambda gt11 library with antibodies directed against spinach chloroplast carbonic anhydrase (carbonate dehydratase, ec 4.2.1.1). sequence analysis revealed an open reading frame of 957 base pairs encoding a polypeptide containing 319 amino acids with a molecular weight of 34,569. this polypeptide is of sufficient size to represent the precursor of spinach chloroplast carbonic anhydrase. the polypeptide contains a sequence of 19 ... | 1990 | 2108138 |
| comparison of the crystal structures of l2 and l8s8 rubisco suggests a functional role for the small subunit. | comparison of the crystal structures of the l2 and l8s8 forms of ribulose-1,5-bisphosphate carboxylase from rhodospirillum rubrum and spinach respectively, reveals a remarkable similarity in the overall architecture of the l2 building blocks in the two enzymes. within the l subunits, no large conformational differences such as domain-domain rotations were found. in spite of a somewhat different packing of the l subunits in the l2 dimer, the active sites of the two enzymes are highly conserved. s ... | 1990 | 2113466 |
| a 31p-nuclear-magnetic-resonance study of nadph-cytochrome-p-450 reductase and of the azotobacter flavodoxin/ferredoxin-nadp+ reductase complex. | 31p-nuclear-magnetic-resonance spectroscopy has been employed to probe the structure of the detergent-solubilized form of liver microsomal nadph--cytochrome-p-450 reductase. in addition to the resonances due to the fmn and fad coenzymes, additional phosphorus resonances are observed and are assigned to the tightly bound adenosine 2'-phosphate (2'-amp) and to phospholipids. the phospholipid content was found to vary with the preparation; however, the 2'-amp resonance was observed in all preparati ... | 1990 | 2115440 |
| residues in three conserved regions of the small subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase are required for quaternary structure. | to explore the role of individual residues in the small subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase (ec 4.1.1.39), small subunits with single amino acid substitutions in three regions of relative sequence conservation were produced by directed mutagenesis of the rbcs gene from anabaena 7120. these altered small subunits were cosynthesized with large subunits (from an expressed anabaena rbcl gene) in escherichia coli. mutants were analyzed for effects on quaternary structure and ca ... | 1990 | 2116005 |
| lack of regio- and stereospecificity in oxidation of (+) camphor by streptomyces griseus enriched in cytochrome p-450soy. | oxidation of (+) camphor by cytochrome p-450soy-enriched intact cells of streptomyces griseus resulted in the formation of one major and several minor metabolites. the minor metabolites were identified as 3-endo-hydroxycamphor (2%), 5-endo-hydroxycamphor (7%), 5-exo-hydroxycamphor (9%), 2,5-diketobornane (2%), and camphorquinone (3%). the major metabolite was isolated and conclusively identified as 6-endo-hydroxycamphor (60%). when supplemented with nadph, spinach ferredoxin:nadp oxidoreductase ... | 1990 | 2116789 |
| the purification and preliminary x-ray diffraction studies of recombinant synechococcus ribulose-1,5-bisphosphate carboxylase/oxygenase from escherichia coli. | x-ray crystallographic diffraction data has been collected for recombinant hexadecameric ribulose-p2 carboxylase from the cyanobacterium synechococcus pcc6301 expressed in escherichia coli. the enzyme has been purified and then crystallized in a number of crystal forms from polyethylene glycol solutions. the best crystals were obtained with enzyme that was first activated with the cofactors co2 and mg2+ in the presence of the tight-binding intermediate analogue, 2'-carboxyarabinitol 1,5-bisphosp ... | 1990 | 2118521 |
| n-terminal amino acid sequence analysis of small subunits of photosystem i reaction center complex from a thermophilic cyanobacterium, synechococcus elongatus nägeli. | four small subunits (14, 13, 10, and 8 kda) of the photosystem i reaction center complex were isolated from a thermophilic cyanobacterium synechococcus elongatus and their n-terminal amino acid sequences determined. sequence analysis of the 10-kda subunit revealed that the distribution of cysteine residues, cys-x-x-cys-x-x-cys-x-x-x-cys-pro, is characteristic of bacterial-type ferredoxins, and that its partial sequence is highly homologous to that deduced from the chloroplast gene frx a of liver ... | 1990 | 2119498 |
| adenylate cyclase activity in cyanobacteria: activation by ca(2+)-calmodulin and a calmodulin-like activity. | an adenylate cyclase activity was partially characterized in the cyanobacterium anabaena sp. the enzyme activity is found in soluble cell fractions and shows an apparent molecular weight of about 183,400. this adenylate cyclase is activated by ca2+ and bovine brain or spinach calmodulin and it is inhibited by egta and some phenothiazine derivatives. furthermore, anabaena sp. extracts contain a calmodulin-like activity which stimulates bovine brain cyclic amp phosphodiesterase and the anabaena ad ... | 1990 | 2121284 |
| purification and characterization of acyl carrier protein from two cyanobacteria species. | the acyl carrier protein (acp), an essential protein cofactor for fatty acid synthesis, has been isolated from two cyanobacteria: the filamentous, heterocystous, anabaena variabilis (atcc 29211) and the unicellular synechocystis 6803 (atcc 27184). both acps have been purified to homogeneity utilizing a three-column procedure. synechocystis 6803 acp was purified 1800-fold with 67% yield, while a. variabilis acp was purified 1040-fold with 50% yield. yields of 13.0 micrograms acp/g synechocystis 6 ... | 1990 | 2123456 |
| the chloroplast cf0i subunit can replace the b-subunit of the f0f1-atpase in a mutant strain of escherichia coli k12. | the amino acid sequence of the cf0i subunit from the chloroplast f0f1-atpase has only a low similarity to the amino acid sequence of the b-subunit of the e. coli f0f1-atpase. however, secondary and tertiary structure predictions plus the distribution of hydrophobic and hydrophilic amino acids have indicated that these two subunits serve a similar function. this proposition was investigated directly. a cdna clone for the chloroplast atpf gene, encoding the cf0i subunit, was altered by site-direct ... | 1990 | 2137012 |
| the primary structure of the gamma-subunit of the atpase from synechocystis 6803. | the nucleotide sequence of the gene coding for the f0f1-atpase gamma-subunit (atpc) from the transformable cyanobacterium synchocystis 6083 has been determined. the deduced translation product consists of 314 amino acid residues and is highly homologous (72% identical residues) to the sequences of other cyanobacterial gamma-subunits. the synechocystis 6803 sequence is also homologous to the chloroplast gamma-sequence. like in the other cyanobacterial subunits, only the first of the 3 cysteine re ... | 1990 | 2137788 |
| the divergently transcribed rbcl and atpb genes of tobacco plastid dna are separated by nineteen base pairs. | the in vivo transcripts of the tobacco chloroplast gene for the beta subunit of the atpase (atpb) were examined. in tobacco, like spinach, the atpb gene encodes multiple transcripts. six tobacco atpb transcripts are present in vivo, with 5' ends at positions "-90", "-255", "-290", "-490", "-500" and "-610" relative to the translation initiation site. the 5' end of the atpb gene ("-610" position) is 20 base pairs from the 5' end of the rbcl gene, coded for on the complementary strand. the "-255", ... | 1990 | 2138063 |
| induction by different thioredoxins of atpase activity in coupling factor 1 from spinach chloroplasts. | atpase activity of the coupling factor 1, cf1, isolated from spinach chloroplasts, was enhanced by reduction with dithiothreitol. reduced thioredoxins from spinach chloroplasts, escherichia coli and human lymphocytes replaced dithiothreitol as reductant and activator of the atpase. cf1 must be in an oxidized activated state to be further activated by reduced thioredoxin. this state was obtained either by heating cf1 or removing the inhibitory intrinsic epsilon subunit from cf1. efficiency and pr ... | 1990 | 2140277 |
| f0f1-atpase of plant mitochondria: isolation and polypeptide composition. | a simple and high yield purification procedure for the isolation of f0f1-atpase from spinach leaf mitochondria has been developed. this is the first report concerning purification and composition of the plant mitochondrial f0f1-atpase. the enzyme is selectively extracted from inner membrane vesicles with the zwitterionic detergent, 3-[(3-cholamidopropyl) dimethyl ammonio]-1- propane sulfonate (chaps). the purified enzyme exhibits a high oligomycin-sensitive atpase activity (3,6 mumol.min-1.mg-1) ... | 1990 | 2143900 |
| isolation and characterization of the constitutive acyl carrier protein from rhizobium meliloti. | rhizobium species produce an inducible acyl carrier protein (acp), encoded by the nodf gene, that somehow functions in an exchange of cell signals between bacteria and specific plant hosts, leading to nodulation of plant roots and symbiotic nitrogen fixation, as well as a constitutive acp needed for the synthesis of essential cell lipids. the periplasmic cyclic glucans of rhizobium spp. are also involved in specific rhizobium-plant interaction. these glucans are strongly similar to the periplasm ... | 1990 | 2144277 |
| expression of subunit iii of the atp synthase from spinach chloroplasts in escherichia coli. | expression of subunit iii of the atp synthase from spinach chloroplasts in escherichia coli has been achieved. although the protein is inserted into the bacterial cytoplasmic membrane, formation of a functional fo complex was not observed. | 1990 | 2146153 |
| analysis of chloroplast promoters using bidirectional transcription vectors. | spinach chloroplast rna polymerase has been shown to efficiently terminate transcription at the threonine attenuator (thra) from escherichia coli. in this study, efficient transcription termination by the chloroplast rna polymerase was observed at a second prokaryotic terminator, the histidine attenuator (hisa) from salmonella typhimurium. termination occurred regardless of the orientation of either attenuator. in higher-plant chloroplast dna, the genes for the beta subunit of the atpase (atpb) ... | 1990 | 2151732 |