Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
|---|
| an o-acetylserine (thiol) lyase cdna from spinach. | 1993 | 8278530 | |
| ent-kaurene biosynthesis is enhanced by long photoperiods in the long-day plants spinacia oleracea l. and agrostemma githago l. | the effect of photoperiod on ent-kaurene biosynthesis was determined in the long-day (ld) plants spinach (spinacia oleracea l.) and agrostemma githago l. further metabolism of ent-kaurene was blocked by application of the growth retardant tetcyclacis, and ent-kaurene accumulation was measured by isotopic dilution using gas chromatography-selected ion monitoring (gc-sim) (e. grosselindemann, j.e. graebe, d. stöckl, p. hedden [1991] plant physiol 96: 1099-1104). in spinach, the rate of ent-kaurene ... | 1993 | 8278497 |
| identification of the major regulatory phosphorylation site in sucrose-phosphate synthase. | sucrose-phosphate synthase (sps; ec 2.4.1.14) is regulated in part by reversible protein phosphorylation. when dephospho-sps is partially purified from illuminated spinach leaves and incubated with [gamma-32p]atp the enzyme is phosphorylated by a copurifying protein kinase. in this report, 32p-phosphopeptides from tryptic digests of in vitro phosphorylated sps were purified by metal-ion affinity chromatography and reversed-phase high-performance liquid chromatography. three distinct 32p-phosphop ... | 1993 | 8274010 |
| spectroscopic evidence from site-directed mutants of synechocystis pcc6803 in favor of a close interaction between histidine 189 and redox-active tyrosine 160, both of polypeptide d2 of the photosystem ii reaction center. | the reaction center of photosystem ii of oxygenic photosynthesis contains two redox-active tyrosines called z and d, each of which can act as an electron donor to the oxidized primary electron donor, p680+. these tyrosines are located in homologous positions on the third transmembrane alpha-helix of each of the two homologous polypeptides, d1 and d2, that comprise the reaction center. tyrosine d of polypeptide d2 has been proposed, upon oxidation, to give up its phenolic proton to a nearby basic ... | 1993 | 8257709 |
| the x-ray structure of synechococcus ribulose-bisphosphate carboxylase/oxygenase-activated quaternary complex at 2.2-a resolution. | the structure of the hexadecameric ribulose-bisphosphate carboxylase/oxygenase from synechococcus pcc6301 has been solved to 2.2-a resolution. crystallization was in the presence of co2, mg2+, and 2'-carboxyarabinitol bisphosphate to form a stable enzyme quaternary complex that mimics one of the intermediate states of the carboxylation reaction. the structure was solved by molecular replacement using the coordinates of spinach carboxylase. the deviations in c alpha positions of the l- and s-subu ... | 1993 | 8245022 |
| a novel structural basis for membrane association of a protein: construction of a chimeric soluble mutant of (s)-mandelate dehydrogenase from pseudomonas putida. | the (s)-mandelate dehydrogenase (mdh) from pseudomonas putida (atcc 12633) is the only membrane-associated member of a homologous family of fmn-dependent, alpha-hydroxy acid dehydrogenases/oxidases that includes the structurally characterized glycolate oxidase from spinach (gox). we have correlated the membrane association of mdh to a polypeptide segment in the interior of the primary sequence. this has been accomplished by construction of a chimeric enzyme in which the putative membrane-binding ... | 1993 | 8241149 |
| protein phosphatase 2a and its [3h]cantharidin/[3h]endothall thioanhydride binding site. inhibitor specificity of cantharidin and atp analogues. | the target site for cantharidin (ca) and its analogues was isolated recently from mouse liver and identified as protein phosphatase (pp2a) in the heterodimeric form known as pp2a2. the most toxic ca analogue, endothall thioanhydride (eta) (mouse i.p. ld50 0.3 mg/kg), appears to have the same binding site in mouse liver and brain based on studies comparing [3h]eta and [3h]ca. atp and its nonhydrolyzable analogues and pyrophosphate and related compounds including phosphonoformic acid inhibited bot ... | 1993 | 8240393 |
| rapid biorecognition assay for herbicides in biological matrices. | a rapid assay capable of detecting several commonly used herbicides at nanogram per milliliter concentrations in biological fluids is described. the assay is based on inhibition of photosynthetic electron transport in spinach thylakoids by the target compounds with colorimetric detection using a redox dye. using a microtiter plate format, high throughput assays of water, urine, and homogenized tissue were performed in minutes with minimal sample preparation. detection limits of 3 ng/ml for atraz ... | 1993 | 8238935 |
| impact of some commonly used egyptian diets on plasma lipids profiles of rats. | seven types of diets commonly consumed in egypt were studied in hyperlipemic rats. each of the seven diets were fed to a group of hyperlipemic rats. the diets contain white beans and whole wheat bread (diet 1); cabbage and peas (2); spinach and carrots (3); whole wheat bread and bean sprouts (4); whole wheat bread, white beans and peas (5); white beans and carrots (6) and the last diet contains peas and carrots (7). the experiment continued for 5 weeks, at the end of which different plasma lipid ... | 1993 | 8237082 |
| formation of the active site of ribulose-1,5-bisphosphate carboxylase/oxygenase by a disorder-order transition from the unactivated to the activated form. | ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco) catalyzes the key first step in photosynthetic co2 fixation, the reaction that incorporates co2 into sugar. in this study, refined crystal structures of unactivated tobacco rubisco and activated rubisco from spinach and tobacco, in complex with the reaction-intermediate analog 2-carboxyarabinitol 1,5-bisphosphate (cabp), are compared. both plant enzymes are hexadecameric complexes of eight large and eight small subunits with a total relat ... | 1993 | 8234342 |
| the inactivation of fe-s cluster containing hydro-lyases by superoxide. | we report in this paper that highly purified escherichia coli dihydroxy-acid dehydratase, fumarase a, fumarase b, and mammalian aconitase are inactivated by o2- with second order rate constants in the range of 10(6) to 10(7) m-1 s-1. each of these enzymes belongs to the hydro-lyase class and contains catalytically active [4fe-4s] clusters. simultaneous with inactivation by o2- is the release of iron from their clusters. our working hypothesis is o2- inactivates these enzymes by oxidizing their c ... | 1993 | 8226748 |
| a 42 bp promoter fragment of the gene for subunit iii of photosystem i (psaf) is crucial for its activity. | the promoter of the gene for the subunit iii of photosystem i reaction center (psaf) from spinach has been dissected and studied via promoter/gus gene fusions in transgenic tobacco. it possesses an architecture that differs from any other spinach promoter of genes encoding proteins involved in photosynthesis studied to date. a 42 bp region located between -220 and -179 bp upstream of the transcription start site has been identified that is indispensable for expression and binds a trans-acting fa ... | 1993 | 8220479 |
| s1f binding site is related to but different from the light-responsive gt-1 binding site and differentially represses the spinach rps1 promoter in transgenic tobacco. | nuclear genes encoding plastid ribosomal proteins are more highly expressed in leaves than in roots. this leaf-specific induction seems to be light-independent. we have previously characterized a spinach nuclear factor s1f binding to a cis-element within the rps1 promoter, which negatively regulates both the rps1 and the cauliflower mosaic virus 35s promoters in transient expression assays. here, we show that the s1f binding site is related to but different from the light-responsive box ii of th ... | 1994 | 8206981 |
| in vitro effect of vegetable and fruit juices on the mutagenicity of 2-amino-3-methylimidazo[4,5-f]quinoline, 2-amino-3,4-dimethylimidazo[4,5-f]quinoline and 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline. | the antimutagenic potencies of the juices of 28 fruits and 34 vegetables commonly consumed in germany were investigated with respect to the mutagenic activities induced by 2-amino-3-methyl[4,5-f]-quinoline (iq), and in part by 2-amino-3,4-dimethylimidazo[4,5-f]quinoline (meiq) or 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (meiqx) in salmonella typhimurium ta98 and ta100. with iq, weak to strong antimutagenic activities were found in 68% of the fruits and 73% of the vegetables that were tested ... | 1994 | 8206443 |
| a functional heterologous electron-transfer protein complex: desulfovibrio vulgaris flavodoxin covalently linked to spinach ferredoxin-nadp+ reductase. | the water-soluble carbodiimide, n-ethyl-3-(3-dimethylaminopropyl)carbodiimide was found to readily promote formation of cross-links between spinach ferredoxin-nadp+ reductase and bacterial flavodoxins. the covalent complex between ferredoxin-nadp+ reductase and the desulfovibrio vulgaris flavodoxin had a stoichiometry of 1 mol of flavodoxin per mole of the reductase, as assessed by denaturing electrophoresis, gel filtration and spectral analysis. the reductase moiety of the cross-linked complex ... | 1994 | 8203913 |
| a glycine to aspartic acid change in the moco domain of nitrate reductase reduces both activity and phosphorylation levels in arabidopsis. | nitrate reductase (nr), the first enzyme in the nitrate assimilation pathway, is regulated post-transcriptionally in response to light and co2. in spinach, it has been shown that phosphorylation is one mechanism that mediates this regulation. in this paper, the phosphorylation of nr in arabidopsis is described in both wild-type and nr- mutant plants. a 110-kda protein radiolabeled in vivo with 32po4 was immunoprecipitated with anti-nr antibody from extracts of wild-type plants but not of mutant ... | 1994 | 8182055 |
| kinetic and physical properties of a recombinant rubisco from a chemoautotrophic endosymbiont. | ribulose 1,5 bisphosphate carboxylase/oxygenase (rubisco), which catalyzes the key step in autotrophic co2 fixation, is present at high activity in the symbiont-containing tissues of many hydrothermal vent invertebrates. the genes encoding rubisco from a gill endosymbiont of the hydrothermal vent gastropod alviniconcha hessleri have been cloned, sequenced, and functionally expressed in escherichia coli under control of the lac promoter in the vector pbluescript. the purified protein is a hexadec ... | 1993 | 8180629 |
| comparison of electron transfer kinetics between redox proteins free in solution and electrostatically complexed to a lipid bilayer membrane. | the second-order rate constants obtained in solution for the reduction of horse cytochrome c (cytc; net charge +7) by either clostridium beijerinckii flavodoxin semiquinone (fld; net charge -16) or reduced spinach ferredoxin (fd; net charge -15) decrease monotonically with increasing ionic strength, as expected for reactions between oppositely charged species. although the rate constant for the fld reaction is almost two orders of magnitude larger at low ionic strength than that for fd, the valu ... | 1994 | 8179324 |
| conserved patterns in the cu,zn superoxide dismutase family. | conserved structural and functional features of cu,zn superoxide dismutase enzymes have been studied by comparison of known three-dimensional structures and analysis of the currently available amino acid sequences. for this purpose, the three-dimensional structures of the bovine, spinach and yeast enzymes have been superimposed and the structure-based sequence alignment of 38 different superoxide dismutases has been produced. the evolutionary tree obtained from the alignment indicates that cytos ... | 1994 | 8176730 |
| construction and expression of a flavocytochrome b5 chimera. | a gene has been constructed coding for a chimeric flavocytochrome b5 protein that comprises the soluble domain of rat hepatic cytochrome b5 as the nh2-terminal portion of the chimera and the flavin-containing domain of spinach assimilatory nadh:nitrate reductase as the c terminus. the chimeric protein has been expressed in escherichia coli and purified to homogeneity using a combination of ammonium sulfate precipitation, affinity chromatography on 5'-adp-agarose, anion-exchange chromatography, a ... | 1994 | 8175767 |
| involvement of lysine-88 of spinach ferredoxin-nadp+ reductase in the interaction with ferredoxin. | a mutant of spinach ferredoxin-nadp+ reductase, in which lys-88 has been changed to glutamine, has been obtained by site-directed mutagenesis. the mutant enzyme was fully active as a diaphorase, but partially impaired in ferredoxin-dependent cytochrome c reductase activity. by steady-state kinetics, the km for ferredoxin of the k88q enzyme was found to have increased 10-fold, whereas the kcat was unaffected by the amino acid replacement. the interaction between oxidized ferredoxin and the enzyme ... | 1994 | 8174709 |
| full-length cdna sequences for both ferredoxin-thioredoxin reductase subunits from spinach (spinacia oleracea l.). | full-length cdna clones for ferredoxin-thioredoxin reductase subunits a and b of spinacia oleracea were obtained and their complete nucleotide sequences were determined. the results are compared with other known ftr sequences. | 1994 | 8167141 |
| promoters from genes for plastid proteins possess regions with different sensitivities toward red and blue light. | the light-regulated expression of eight nuclear-encoded genes for plastid proteins from spinach (spinacia oleracea) (rbcs-1 and cab-1; atpc and atpd, encoding the subunits gamma and delta of the atp synthase; pc and fnr; psad and psaf, encoding the subunits ii and iii of photosystem i reaction center) was analyzed with promoter/beta-glucuronidase (gus) gene fusions in transgenic tobacco (nicotiana tabacum and nicotiana plumbaginifolia) seedlings and mature plants under standardized light and gro ... | 1994 | 8165263 |
| structural analysis of the chloroplastic and cytoplasmic aldolase-encoding genes implicated the occurrence of multiple loci in rice. | the genes aldp and aldc-a, encoding the rice chloroplastic (cp) and cytoplasmic (ct) types of aldolase, respectively, were isolated and sequenced, and their transcription start points (tsp) were determined. organization of the two genes was found to differ greatly; aldp consisted of six exons while aldc-a consisted of two exons. the deduced amino acid (aa) sequence of aldp contained a cp stromal targeting signal, followed by a sequence that matches the experimentally determined n-terminal sequen ... | 1994 | 8163192 |
| comparison of cytochrome b-559 content in photosystem ii complexes from spinach and synechocystis species pcc 6803. | cytochrome b-559 is an integral component of photosystem ii complexes from both plants and cyanobacteria. however, the number of cytochrome b-559 associated with the photosystem ii reaction center has been the subject of controversy. some studies have concluded that there is one heme equivalent of cytochrome b-559 per reaction center, some studies have found two, and some studies have reported intermediate values. most of the previous experiments have used only one method to quantitate the anten ... | 1994 | 8155657 |
| the influence of dietary factors on the risk of urinary stone formation. | the action of various beverages and foods on the composition of the urine in the circadian rhythm and in the 24-hour urine has been investigated under standardized conditions. orange juice leads to a significant increase of urinary ph and citric acid excretion. black tea leads to a raised excretion of oxalic acid by only 7.9%. in the short term, beer increases diuresis, but afterwards leads to a compensatory antidiuresis with increased risk of stone formation. depending on their composition, min ... | 1993 | 8146611 |
| [molecular genetics and biotechnology in medicinal plants: studies by transgenic plants]. | the advances in molecular genetics and biotechnology in the field of medicinal plant research are discussed with focusing on the works using transgenic plants. differentiated organ cultures and transgenic teratomas, incited by the infection with mutants of agrobacterium ti and ri plasmids, were established in quinolizidine-alkaloid producing plants and solanaceae plants. these cultured cells were used for the production and bioconversion of specific alkaloids produced in these plants. the method ... | 1994 | 8133455 |
| electron transfer from plastocyanin to photosystem i. | mutant plastocyanins with leu at position 10, 90 or 83 (gly, ala and tyr respectively in wildtype) were constructed by site-specific mutagenesis of the spinach gene, and expressed in transgenic potato plants under the control of the authentic plastocyanin promoter, as well as in escherichia coli as truncated precursor intermediates carrying the c-terminal 22 amino acid residues of the transit peptide, i.e. the thylakoid-targeting domain that acts as a bacterial export signal. the identity of the ... | 1994 | 8131737 |
| application of neural networks to automated assignment of nmr spectra of proteins. | simulated neural networks are described which aid the assignment of protein nmr spectra. a network trained to recognize amino acid type from tocsy data was trained on 148 assigned spin systems from e. coli acyl carrier proteins (acps) and tested on spin systems from spinach acp, which has a 37% sequence homology with e. coli acp and a similar secondary structure. the output unit corresponding to the correct amino acid is one of the four most activated units in 83% of the spin systems tested. the ... | 1994 | 8130640 |
| multicopy gtpase center protein l12 of arabidopsis chloroplast ribosome is encoded by a clustered nuclear gene family with the expressed members closely linked to trna(pro) genes. | a conserved architectural feature of ribosomes is a protuberance (the stalk) in the large subunit, essential for ribosomal interactions with translational factors and gtp hydrolysis and generated by two dimers of l12, the only multicopy protein in ribosomes. in higher plants, the rpl12 gene for chloroplast l12 is located in the nucleus. we report here the cloning and sequencing of this nuclear gene from arabidopsis thaliana, revealing the first gene family for a chloroplast ribosomal protein (rp ... | 1994 | 8125949 |
| expression of genes encoding the tobacco chloroplast phosphate translocator is not light-regulated and is repressed by sucrose. | a cdna encoding the complete precursor of the phosphate translocator of the chloroplast inner envelope membrane has been isolated from a tobacco leaf (nicotiana tabacum cv. samsun) lambda gt 11 library. the tobacco cdna is 1546 bp in length and encodes a precursor protein of 401 amino acid residues with a deduced molecular weight of 43705. a putative processing site between ala-73 and ala-74 of the precursor protein is suggested by comparison with the n-terminal sequences of the pea and spinach ... | 1994 | 8121415 |
| slipped-strand mispairing in a plastid gene: rpoc2 in grasses (poaceae). | an exception to the generally conservative nature of plastid gene evolution is the gene coding for the beta" subunit of rna polymerase, rpoc2. previous work by others has shown that maize and rice have an insertion in the coding region of rpoc2, relative to spinach and tobacco. to assess the distribution of this extra coding sequence, we surveyed a broad phylogenetic sample comprising 55 species from 17 angiosperm families by using southern hybridization. the extra coding sequence is restricted ... | 1994 | 8121278 |
| a cdna encoding the endoplasmic reticulum-luminal heat-shock protein from spinach (spinacia oleracea l.). | 1994 | 8115556 | |
| the dark stable tyrosine radical of photosystem 2 studied in three species using endor and epr spectroscopies. | the dark stable neutral tyrosine radical yd. of photosystem 2 (ps2) has been studied using electron nuclear double-resonance (endor) and electron paramagnetic resonance (epr) spectroscopies. the proton hyperfine coupling constants of all four ring protons and both beta-methylene protons have been determined for yd. in three species covering the range of oxygenic organisms; a higher plant (spinach), an alga (chlamydomonas reinhardtii), and a cyanobacterium (phormidium laminosum). it has generally ... | 1994 | 8110776 |
| identification of the uridine-binding domain of sucrose-phosphate synthase. expression of a region of the protein that photoaffinity labels with 5-azidouridine diphosphate-glucose. | the uridine diphosphate-glucose (udp-glc) binding domain of sucrose-phosphate synthase (sps) was identified by overexpressing part of the gene from spinach (spinacia oleracea). degenerate oligonucleotide primers corresponding to two tryptic peptides common to both the full-length 120-kd sps subunit and an 82-kd form that photoaffinity labeled with 5-azidouridine diphosphate-glucose (5-n3udp-glc) were used in a polymerase chain reaction to isolate a partial cdna clone. comparison of the deduced a ... | 1993 | 8108511 |
| the atpb and rbcl promoters in plastid dnas of a wide dicot range. | the plastid atpb-rbcl intergene has been analyzed within a wide range of plants covering the major dicot lineages. new sequences from 13 plant species were determined and aligned with three already-known sequences. the promoters of the rbcl and the atpb genes were localized and analyzed according to published observations in spinach and tobacco. the evolutionary conservation of two atpb promoters, separated by 113-262 nucleotides, is strong support that both are functionally active, and it also ... | 1994 | 8083883 |
| structure and evolution of the largest chloroplast gene (orf2280): internal plasticity and multiple gene loss during angiosperm evolution. | we have determined the nucleotide sequence of the pelargonium x hortorum orf2280 homolog, the largest gene in the plastid genome of most land plants, and compared it to published homologs from nicotiana tabacum, epifagus virginiana, spinacia oleracea, and marchantia polymorpha. multiple alignment of protein sequences requires an extraordinary number of gaps, indicating a very high frequency of insertion/deletion events during the evolution of the protein; however, the overall predicted size of t ... | 1994 | 8082181 |
| relative importance of risk factors in bladder carcinogenesis: some new results about mediterranean habits. | in the mediterranean region of france where bladder cancer mortality and incidence are high, a case-control study with 219 male incident cases and 794 randomized, male population-controls was carried out in 1987-89 to investigate bladder cancer risk factors and more specifically, regional factors. a stepwise logistic regression was applied to the data. this investigation confirms the role of tobacco and of certain occupational exposures in bladder carcinogenesis. there was a significant dose-res ... | 1994 | 8080944 |
| isolation of a novel soybean gene encoding a mitochondrial atp synthase subunit. | a novel atp synthase gene from soybean has been cloned and characterized. a subunit from the fa portion of the complex is encoded by two nuclear genes. the genomic clone(s) contain five exons encoding a protein of 179 amino acids. the amino terminal end contains many properties of a mitochondrial targeting sequence and preliminary in vitro import studies indicate that there is a cleavable precursor of approximately 30 amino acids. the predicted protein sequence shows high homology with the n-ter ... | 1994 | 8080267 |
| the role of rna editing in conservation of start codons in chloroplast genomes. | open reading frames (orfs), encoded by the plastid genomes of tobacco, liverwort, rice and maize were aligned with a view to studying the conservation of translational start and stop codons created by rna editing of homologous genes. it became evident that most of the homologous orfs have conserved translation start and stop signals at the gene level. however, some of the orfs show differences with respect to extensions of their 3' and 5' terminal regions. for example, the proposed n-termini of ... | 1994 | 8076816 |
| feruloyl oligosaccharides from cell walls of suspension-cultured spinach cells and sugar beet pulp. | cell walls of suspension-cultured spinach cells and sugar beet pulp were separately hydrolyzed with driselase. a feruloyl arabinobiose was isolated from both spinach cells and sugar beet. four feruloyl oligosaccharides were obtained from sugar beet. the four oligosaccharides were characterized by nmr spectroscopy, methylation analysis and fab-ms. | 1994 | 8075900 |
| a prolyl endoproteinase that acts specifically on the extrinsic 18-kda protein of photosystem ii: purification and further characterization. | an endoproteinase, which specifically cleaves the pro12-leu13 bond of the extrinsic 18-kda protein of psii, was purified from psii membranes of spinach. the presence of 0.05% (w/v) tween 20 and 1 m nacl was essential for maintenance of proteolytic activity during the purification. the molecular mass of the enzyme was estimated to be 95 kda by gel-filtration chromatography. active fractions contained a polypeptide of 165 kda that was converted into diffusely stained polypeptides of 54 kda upon re ... | 1994 | 8075899 |
| [the effect of thylakoid lipids on cytochrome bf complex activity]. | the effects of glycerolipids from thylakoid membranes on the electron transport and proton-translocating activities of the cytochrome bf complex from spinach have been studied. when the cytochrome bf complex was mixed with the lipids from the wild type of synechocystis pcc6803 containing mono-, di- and triunsaturated lipid molecules, the activity of the electron transport was stimulated by dgdg and pg, but not by mgdg and sqdg. essentially the same effect, though less significant, was observed w ... | 1994 | 8075248 |
| isolation of a mrna encoding a nucleoside diphosphate kinase from tomato that is up-regulated by wounding. | a cdna clone (tab2) encoding a nucleoside diphosphate (ndp) kinase has been isolated from a tomato (lycopersicon esculentum mill. cv. ailsa craig) cdna library. the clone is 590 bp long and exhibits a high degree of sequence identity with spinach ndp kinases i and ii, pisum sativum ndp kinase i, arabidopsis thaliana ndp kinase, drosophila melanogaster ndp kinase, dictyostelium discoideum ndp kinase and human nm 23-h1 and nm23-h2. northern analysis has revealed that the mrna encoded by tab2 is up ... | 1994 | 8061324 |
| expression of the 23 kda protein from the oxygen-evolving complex of higher plants in escherichia coli. | the 23 kda protein from the oxygen-evolving complex of higher plants regulates the binding of one ca2+ ion, which is an essential cofactor of water splitting. in this report its expression in escherichia coli is described. the 23 kda protein was expressed and secreted to the periplasm where it accumulated in a soluble form. after purification by cation exchange chromatography the recombinant protein was found to nacl-washed photosystem ii. detailed analysis of oxygen-evolving activity demonstrat ... | 1994 | 8061039 |
| topography of the heme prosthetic group of cytochrome b-559 in the photosystem ii reaction center. | the topography of the heme prosthetic group of cytochrome b-559 of the photosystem ii reaction center was determined from measurement of the orientation of its alpha- and beta-polypeptides in thylakoid membranes of spinach chloroplasts and in osmotically disrupted cells of the cyanobacterium synechocystis sp. pcc 6803. the accessibility to trypsin proteolysis of an epitope located near the solvent-exposed n-terminus of the beta-subunit was compared to that of the alpha-subunit, whose n- and c-te ... | 1994 | 8060975 |
| interactions of plant acetohydroxy acid isomeroreductase with reaction intermediate analogues: correlation of the slow, competitive, inhibition kinetics of enzyme activity and herbicidal effects. | n-hydroxy-n-isopropyloxamate (ipoha) is known to inhibit extremely tightly (ki of 22 pm) the bacterial acetohydroxy acid isomeroreductase (ec 1.1.1.86) [aulabaugh and schloss (1990) biochemistry 29, 2824-2830], the second enzyme of the branched-chain-amino-acid-biosynthetic pathway. yet, although the same pathway exists in plant cells, this compound presents only very poor herbicidal action. towards the goal of gaining a better understanding of this behaviour, we have studied the mechanism of in ... | 1994 | 8053906 |
| tissue-specific expression of the large atp synthase gene cluster in spinach plastids. | plastids present in different tissues may vary morphologically and functionally, despite the fact that all plastids within the same plant contain identical genomes. this is achieved by regulation of expression of the plastid genome by tissue-specific factors, the mechanisms of which are not fully understood. the proton translocating atp synthase/atpase is a multisubunit complex composed of nine subunits, six encoded in the plastid and three in the nucleus. we have investigated the tissue-specifi ... | 1994 | 8049363 |
| complementation of escherichia coli uncd mutant strains by a chimeric f1-beta subunit constructed from e. coli and spinach chloroplast f1-beta. | atp-synthesizing f0f1-atpases are complex enzymes consisting of at least eight different subunits. these subunits are conserved during evolution to a very variable degree ranging in pairwise comparison between, for example, escherichia coli and spinach chloroplast from 20% to 66% identical residues. it was surprising to find that some of the less well conserved subunits like delta and epsilon could replace their e. coli counterparts, whereas the highly conserved beta subunit, which carries the a ... | 1994 | 8043596 |
| molecular cloning of a cysteine synthase cdna from citrullus vulgaris (watermelon) by genetic complementation in an escherichia coli cys- auxotroph. | we have isolated cdna clones encoding cysteine synthase (csase, ec 4.2.99.8), which catalyzes the terminal step in cysteine biosynthesis, by direct genetic complementation of a cys- mutation in escherichia coli with an expression library of citrullus vulgaris (watermelon) cdna. the library was constructed from 8-day-old etiolated seedlings of c. vulgaris in the lambda zapii vector, converted to a plasmid library by in vivo excision, and then used for transformation of cysteine auxotroph e. coli ... | 1994 | 8041362 |
| competitive protein-binding radioassay of thiamine in selected biological materials. | a principle of competitive protein-binding radioassay is developed for thiamine determination in some biological samples. thiamine in an assay sample competes with radiolabelled thiamine for sepharose-immobilized buckwheat-seed thiamine-binding protein. a blank sample is prepared by destruction of thiamine in hot alkaline solution. model studies show that the radioassay works in thiamine concentration range of 1-10 microm, in samples of moderate ionic strength (up to 0.25 m nacl) and is specific ... | 1994 | 8040564 |
| desulfoviridin, a multimeric-dissimilatory sulfite reductase from desulfovibrio vulgaris (hildenborough). purification, characterization, kinetics and epr studies. | conditions for the rigorous purification of desulfoviridin, the dissimilatory sulfite reductase from the sulfate-reducing bacterium desulfovibrio vulgaris (hildenborough) have been established. a final purification by fast protein liquid chromatography yields at least three distinct bands that each exhibit the characteristic absorption spectrum of desulfoviridin. two of these have been extensively characterized by amino acid analysis, isoelectric focusing, polyacrylamide gel electrophoresis, and ... | 1994 | 8033912 |
| a cdna clone encoding a spinach 70-kilodalton heat-shock cognate. | 1994 | 8029365 | |
| incidence of yersinia spp. in food in sao paulo, brazil. | this study examined the occurrence of y. enterocolitica and other yersinia species in brazilian food products. samples included raw vegetables (lettuce, spinach, watercress and chicory), raw and pasteurized milk as well as meat and meat products. raw milk samples were obtained in a dairy plant and the other food samples were purchased at the retail level in sao paulo city. yersinia spp. was isolated from raw milk (45.2%), pasteurized milk (14.3%), raw vegetables samples (13.3%) and meat and meat ... | 1994 | 8024978 |
| novel o-d-galacturonoyl esters in the pectic polysaccharides of suspension-cultured plant cells. | driselase digestion of uronate-6-14c-labeled primary walls of cultured spinach (spinacia oleracea l.) cells yielded about 18 novel uronate-containing compounds, most of which could be hydrolyzed by cold dilute alkali to yield oligo-[14c]galacturonides. one typical driselase digestion product (compound 17) yielded alpha-(1-->4)-d-[14c]galacturonotriose(gala3) upon very mild treatment with alkali (50% yield of gala3 in 7.2 min at ph 11 and 25 degrees c). one of the three galacturonate residues in ... | 1993 | 8022945 |
| protein substitution in chloroplast ribosome evolution. a eukaryotic cytosolic protein has replaced its organelle homologue (l23) in spinach. | the chloroplast translational system differs from the eubacterial ones in containing several ribosomal proteins (rps) that have no apparent homologues in eubacteria, and in having their rp genes distributed in two cellular genome compartments. the genes maintained in the organelle genome encode mainly ribosome assembly proteins. the discovery in spinach and related plants (caryophyllidae) of a disrupted chloroplast gene encoding the ribosome assembly protein l23 raised speculations about the tra ... | 1994 | 8021938 |
| the 24 kda outer envelope membrane protein from spinach chloroplasts: molecular cloning, in vivo expression and import pathway of a protein with unusual properties. | the 24 kda outer envelope membrane protein of spinach chloroplasts (omp24) represents a major constituent of this membrane. sequences of tryptic and endoprotease glu-c peptides derived from omp24 allowed the design of oligonucleotides which were used to generate a dna fragment by polymerase chain reaction using spinach cdna as template. this fragment served as a probe to screen a cdna library for a full-length clone of the omp24 coding sequence. the protein predicted from the complete sequence o ... | 1994 | 8018867 |
| structural organization of the spinach endoplasmic reticulum-luminal 70-kilodalton heat-shock cognate gene and expression of 70-kilodalton heat-shock genes during cold acclimation. | the 70-kd heat-shock proteins (hsp70s) are encoded by a multigene family in eukaryotes. in plants, the 70-kd heat-shock cognate (hsc70) proteins are located in organellar and cytosolic compartments of cells in most tissues. previous work has indicated that hsc70 proteins of spinach (spinacia oleracea) are actively synthesized during cold-acclimating conditions. we have isolated, sequenced, and characterized cdna and genomic clones for the endoplasmic reticulum (er) luminal hsc70 protein (immunog ... | 1994 | 8016266 |
| characterization of the kinetic, regulatory, and structural properties of adp-glucose pyrophosphorylase from chlamydomonas reinhardtii. | adp-glucose pyrophosphorylase (adp-glc ppase) from chlamydomonas reinhardtii cells was purified over 2000-fold to a specific activity of 81 units/mg protein, and its kinetic and regulatory properties were characterized. inorganic orthophosphate and 3-phosphoglycerate were the most potent inhibitor and activator, respectively. rabbit antiserum raised against the spinach leaf adp-glc ppase (but not the one raised against the enzyme from escherichia coli) inhibited the activity of the purified alga ... | 1994 | 8016263 |
| effects of protein isolates from radish and spinach leaves on serum lipids levels in rats. | radish and spinach leaf protein isolates (rlp and slp, respectively) were prepared from chilled aqueous 0.2% sodium hydroxide extract of their leaves. the rlp and slp, and those supplemented with methionine (rlp+met and slp+met, respectively) to become equal to casein in methionine content, were compared with casein for their effects on serum cholesterol level in rats fed with a cholesterol-enriched diet for 14 days. each protein isolate was incorporated into the cholesterol-enriched diet to pro ... | 1993 | 8006719 |
| [contact allergic dermatitis caused by plants]. | in order to contribute to the setting of an accurate diagnosis and prophylaxis of phytodermatitis (pd) and to better understand eczematogenic characteristics of some plants, we present results of an allergologic analysis and review the plants which most commonly cause fd in our material. a total of 15 patients presenting with fd was examined. in all the cases we used a standard technique, patch test (pt); in cases supsective of contact urticaria syndrome (cus) we used open pt, while photo pt was ... | 1993 | 7997217 |
| regulation of rdna transcription in chloroplasts: promoter exclusion by constitutive repression. | spinach chloroplasts contain two types of rna polymerases. one is multimeric and escherichia coli-like. the other one is not e. coli-like and might represent a monomeric enzyme of 110 kd. the quantitative relation of the two polymerases changes during plant development. this raises the question, how are plastid genes transcribed that contain e. coli-like and non-e. coli-like promoter elements during developmental phases when both enzymes are present? transcription of the spinach plastid rrn oper ... | 1994 | 7995527 |
| cysteines of chloroplast nadp-malate dehydrogenase form mixed disulfides. | chloroplast nadp-malate dehydrogenase (nadp-mdh) from pea and from spinach was n-terminally truncated by limited proteolysis with staphylococcus aureus protease v8. the resulting monomeric enzymes lacking, respectively, the 37 and 38 n-terminal amino acids were inactive. reduction and addition of low concentrations of guanidine-hcl (50-100 mm) resulted in a highly active enzyme of 850 units per mg protein. equilibration of the truncated enzyme with various glutathione (gsh) redox buffers and ass ... | 1994 | 7988683 |
| segments encoding 5'-untranslated leaders of genes for thylakoid proteins contain cis-elements essential for transcription. | the promoter region -118/-29 of the spinach peth gene encoding the ferredoxin-nadp(+)-oxidoreductase contains crucial cis-elements for the regulated expression, while sequences for the 5'-untranslated leader determine the quantitative expression of chimeric gus gene fusions in transgenic tobacco. deletion of leader sequences in chimeric gus gene fusions of the spinach pete and psaf genes (for plastocyanin and the subunit iii of photosystem i, respectively) results also in a decline in the gus ac ... | 1994 | 7987410 |
| cdna sequence for the plastidic phosphoglucomutase from spinacia oleracea (l.). | 1994 | 7972501 | |
| ribosomes pause during the expression of the large atp synthase gene cluster in spinach chloroplasts. | the large atp synthase gene cluster from spinach (spinacia oleracea) chloroplasts encodes five genes, the last four of which encode subunits of the atp synthase complex. in preliminary experiments (j.k. kim, m.j. hollingsworth [1992] anal biochem 206: 183-188) it was shown that ribosomes pause during translation of these open reading frames. we have examined ribosome pausing in the four atp synthase open reading frames of this gene cluster to determine whether it could affect the final ratio of ... | 1994 | 7972492 |
| laser flash-induced photoreduction of photosynthetic ferredoxins and flavodoxin by 5-deazariboflavin and by a viologen analogue. | laser flash photolysis has been used to compare the kinetics of reduction of ferredoxin isoforms from the green alga monoraphidium braunii, and the ferredoxin and flavodoxin from the cyanobacterium anabaena pcc 7119, by 5-deazariboflavin semiquinone (drfh.) and the viologen analogue 1,1'-propylene-2,2'-bipyridyl (pdq.+). similar ionic strength-independent second-order rate constants (1.4 x 10(8) m-1 s-1) were obtained for the reduction of both algal ferredoxin isoforms by drfh.. for the reductio ... | 1994 | 7972374 |
| isolation and characterization of cdna that encodes a putative mitochondrion-localizing isoform of cysteine synthase (o-acetylserine(thiol)-lyase) from spinacia oleracea. | the cdna clones that encode a putative mitochondrion-localizing isoform of cysteine synthase (o-acetyl-l-serine(thiol)-lyase, o-acetyl-l-serine acetate-lyase (adding hydrogen sulfide), ec 4.2.99.8), which is denoted as cysteine synthase c, were isolated from spinach (spinacia oleracea l.). the cdna encodes a polypeptide of 368 amino acids containing a putative transit peptide of 30-40 amino acids at the n terminus. this leader peptide sequence exhibited several structural features common to othe ... | 1994 | 7961755 |
| purification and characterization of the 30s ribosomal proteins from the bacterium thermus thermophilus. | the total protein mixture of the 30s subunit (tp-30) of the bacterium thermus thermophilus has been purified using reverse-phase hplc and the proteins obtained were identified both by means of two-dimensional polyacrylamide gel electrophoresis as well as by amino-terminal amino acid microsequence analysis. the proteins are numbered according to their primary structural similarity with known prokaryotic ribosomal proteins. eight of them, namely proteins s6, s7, s9, s10, s14, s15, s16 and s17 run ... | 1994 | 7957245 |
| hybrid fo complexes of the atp synthases of spinach chloroplasts and escherichia coli. immunoprecipitation and mutant analyses. | hybrid fo complexes of the atp synthases of spinach chloroplast (cfo) and escherichia coli (efo) were investigated. immunoprecipitations with polyclonal antibodies against the different fo subunits clearly revealed that hybrid fo complexes derived from cfo subunit iii and efo subunits a and b were formed in vivo. in addition, the atpase activities of the hybrid atp synthase, measured in everted cytoplasmic membranes of an atpe mutant strain transformed with the atph gene coding for cfo iii, were ... | 1994 | 7957212 |
| purification and pcr-based cdna cloning of a plastidial n-6 desaturase. | a plastidial membrane-bound n-6 desaturase from spinach (spinacia oleracea) was purified from chloroplast envelope membranes by anion exchange, cation exchange and ferredoxin-affinity chromatography. the molecular mass of the protein was estimated by sds-page to be 40 kda. the highest specific activity of the desaturase in the final preparation was 196 nmol/min per mg protein with free oleic acid as the substrate. the n-terminal amino acid sequence of the blotted protein was determined and used ... | 1994 | 7948918 |
| tissue-specific differences of the mitochondrial protein import machinery: in vitro import, processing and degradation of the pre-f1 beta subunit of the atp synthase in spinach leaf and root mitochondria. | in this study we report the first comparison of the mitochondrial protein import and processing events in two different tissues from the same organism. both spinach leaf and root mitochondria were able to import and process the in vitro transcribed and translated neurospora crassa f1 beta subunit of atp synthase to the mature size product. temperature optimum for protein import, 20 degrees c, was considerably lower than that found in other systems. in spinach leaf mitochondria, the processing pe ... | 1994 | 7948913 |
| characterization and differential expression of dhn/lea/rab-like genes during cold acclimation and drought stress in arabidopsis thaliana. | we have characterized cdnas for two new dhn/lea/rab (dehydrin, late embryogenesis-abundant, responsive to aba)-related genes from arabidopsis thaliana. the two genes were strongly induced in plants exposed to low temperature (4 degrees c) and were accordingly designated lti45 and lti30 (low temperature-induced). the lti45 gene product contains the conserved serine stretch and three lysine-rich repeats characteristic of dhn/lea/rab proteins and is very similar to another low temperature-responsiv ... | 1994 | 7948863 |
| reconstitution of the spinach oxygen-evolving complex with recombinant arabidopsis manganese-stabilizing protein. | the psbo gene of cyanobacteria, green algae and higher plants encodes the precursor of the 33 kda manganese-stabilizing protein (msp), a water-soluble subunit of photosystem ii (psii). using a pet-t7 cloning/expression system, we have expressed in escherichia coli a full-length cdna clone of psbo from arabidopsis thaliana. upon induction, high levels of the precursor protein accumulated in cells grown with vigorous aeration. in cells grown under weak aeration, the mature protein accumulated upon ... | 1994 | 7948862 |
| isolation of multiple dimeric forms of phosphoribulokinase from an alga and a higher plant. | dimeric phosphoribulokinase from either spinach (spinacia oleracea) leaf or from the green alga, scenedesmus obliquus can be separated into three distinct forms by hydrophobic interaction chromatography. variation of the redox conditions prior to and during chromatography resulted in specific forms of phosphoribulokinase being eluted. it is suggested that three dimeric forms of phosphoribulokinase differ in the extent of disulfide bond formation between cys-16 and cys-55 in each of the two subun ... | 1994 | 7947971 |
| crystallization and preliminary crystallographic data for acetohydroxy acid isomeroreductase from spinacia oleracea. | acetohydroxy acid isomeroreductase (ec 1.1.1.86) is one of the enzymes involved in branched-chain amino acid biosynthesis. the enzyme from spinach (spinacia oleracea) leaves has been crystallized using the hanging drop vapour diffusion method. the free enzyme crystallized from polymethylene glycol solutions, but these crystals were unsuitable for x-ray diffraction analysis. in the presence of nadph, mg(2+) and a reaction intermediate analogue (2-dimethylphosphinoyl-2-hydroxy acetic acid (hoe 704 ... | 1994 | 7932712 |
| purification and characterization of the 26 s proteasome from spinach leaves. | the 26 s proteasome complex catalyzing atp-dependent breakdown of ubiquitin-ligated proteins was purified from spinach leaves to near homogeneity by chromatography on deae-cellulose, gel filtration on biogel a-1.5, and glycerol density gradient centrifugation. the purified enzyme was shown to degrade multi-ubiquitinated, but not unmodified, lysozymes in an atp-dependent fashion coupled with atpase activity supplying energy for proteolysis and isopeptidase activity to generate free ubiquitin. by ... | 1994 | 7929295 |
| structure-function relationships of cyanobacterial adp-glucose pyrophosphorylase. site-directed mutagenesis and chemical modification of the activator-binding sites of adp-glucose pyrophosphorylase from anabaena pcc 7120. | chemical modification studies of spinach leaf adp-glucose pyrophosphorylase with pyridoxal-p have shown that a highly conserved lysyl residue near the c terminus might be involved in the binding of 3-p-glycerate, the allosteric activator. site-directed mutagenesis of the corresponding residue (lys419) of the anabaena enzyme was performed to determine the role of this conserved residue. replacing lys419 with either arginine, alanine, glutamine, or glutamic acid produced mutant enzymes with appare ... | 1994 | 7929064 |
| plant proteins that bind to the 3'-terminal sequences of the negative-strand rna of three diverse positive-strand rna plant viruses. | the replication of positive-strand rna plant viruses, which involves both virus-encoded and plant-encoded proteins, takes place in two stages: synthesis of a negative-strand rna using the genomic positive-strand rna as a template and synthesis of progeny positive-strand rna using the negative-strand rna as a template. using gel mobility shift and photochemical crosslinking assays, we have identified three proteins of m(r) 32k, 50k and 100k in extracts of tobacco and spinach leaves that bind to t ... | 1994 | 7925996 |
| isolation and 1h-nmr spectroscopic identification of poly(3-hydroxybutanoate) from prokaryotic and eukaryotic organisms. determination of the absolute configuration (r) of the monomeric unit 3-hydroxybutanoic acid from escherichia coli and spinach. | trace amounts of poly[(r)-3-hydroxybutanoate] were isolated from competent escherichia coli, spinach, bovine serum albumin, beef heart mitochondria, and aortal tissues, all sources in which it is not accumulated as storage material. its identity was in all cases proved by 1h-nmr spectroscopy. in some runs, the poly[(r)-3-hydroxybutanoate] isolated from competent e. coli also contained some 3-hydroxyvalerate, an observation confirmed by 1h-nmr spectroscopy and gas chromatography. the absolute con ... | 1994 | 7925344 |
| introduction of a heterologous editing site into the tobacco plastid genome: the lack of rna editing leads to a mutant phenotype. | the psbf mrna is edited in spinach plastids by a c to u conversion, changing a serine to a conserved phenylalanine codon. in tobacco at this position a phenylalanine codon is present at the dna level, and the psbf mrna here is not edited. to test if the psbf editing capacity is evolutionarily conserved, the tobacco psbf gene was modified to match the corresponding spinach sequence. the endogenous tobacco gene was replaced with the modified copy using biolistic transformation. we report here that ... | 1994 | 7925303 |
| promoter and leader sequences of the spinach psad and psaf genes direct an opposite light response in tobacco cotyledons: psad sequences downstream of the atg codon are required for a positive light response. | subunits ii and iii of the photosystem i reaction centre are encoded by the nuclear genes psad and psaf, respectively. in spinach, the expression of both genes is highly synchronized with regard to time, space and in response to stimulators such as light. nevertheless, promoter sequences as well as the design and location of regulatory elements are strikingly different. promoter and leader of psaf, when fused to the gus reporter gene, direct a positive light response in the cotyledons of transge ... | 1994 | 7920722 |
| over-production, renaturation and reconstitution of delta and epsilon subunits from chloroplast and cyanobacterial f1. | we studied the functioning of chimeric f0f1-atpases by replacing subunits delta and epsilon of spinach cf1 with their counterparts from synechocystis sp. pcc 6803. the sequence identities between these subunits are 26 and 41%, respectively. for a systematic approach to such studies and later extension to genetically modified subunits recombinant proteins are required. the genes coding for spinach and synechocystis delta and epsilon were cloned into pet3 expression vectors and expressed in escher ... | 1994 | 7918533 |
| electron transfer from the acceptor a1 to the iron-sulfur centers in photosystem i as studied by transient epr spectroscopy. | the electron transfer in photosystem i (ps i) from the secondary acceptor a1 to the iron-sulfur centers is studied by x-band transient epr with a time resolution of approximately 50 ns. results are presented for a series of different ps i preparations from the cyanobacterium synechococcus 6301 ranging from whole cells to core particles in which the iron-sulfur centers have been successively removed. in addition, results from ps i preparations from spinach and the cyanobacterium synechocystis 680 ... | 1994 | 7918396 |
| common sequence motifs coding for higher-plant and prokaryotic o-acetylserine (thiol)-lyases: bacterial origin of a chloroplast transit peptide? | a comparison of the amino acid sequence of o-acetylserine (thiol)-lyase (ec 4.2.99.8) from escherichia coli and the isoforms of this enzyme found in the cytosolic and chloroplastic compartments of spinach (spinacia oleracea) leaf cells allows the essential lysine residue involved in the binding of the pyridoxal 5'-phosphate cofactor to be identified. the results of further sequence comparison of cdnas coding for these proteins are discussed in the frame of the endosymbiotic theory of chloroplast ... | 1993 | 7916619 |
| characterization of three related low-temperature-regulated cdnas from winter brassica napus. | a cdna clone, pbn115, encoding a low-temperature-regulated transcript in winter brassica napus has been isolated. northern blot analyses show that levels of transcripts hybridizing to pbn115 increase within 24 h of exposure of b. napus to low temperature, peak at 3 d, and then remain at an elevated level for the duration of the cold treatment (up to 10 weeks). transferring plants from 2 degrees c to room temperature results in the loss of detectable transcripts hybridizing to pbn115 within 1 d. ... | 1993 | 7904076 |
| tight nucleotide binding sites and atpase activities of the rhodospirillum rubrum rrf1-atpase as compared to spinach chloroplast cf1-atpase. | solubilized rhodospirillum rubrum rrf1-atpase, depleted of loosely bound nucleotides, retains 2.6 mol of tightly bound atp and adp/mol of enzyme. incubation of the depleted rrf1 with mg(2+)-atp or mg(2+)-amp-pnp, followed by passage through two successive sephadex centrifuge columns, results in retention of a maximal number of 4 mol of tightly bound nucleotides/mol of rrf1. they include 1.5 mol of nonexchangeable atp, whereas all tightly bound adp is fully exchangeable. a similar retention of on ... | 1994 | 7896772 |
| nucleotide sequence of a gene for nitrite reductase from arabidopsis thaliana. | a nitrite reductase (nir) gene was recovered from arabidopsis thaliana genomic library by the homology with a cdna of spinach nir and sequenced. based on the comparison with the spinach cdna, the arabidopsis nir gene was concluded to contain 4 exons [exon 1 of 376 bp (beginning with atg start codon), exon 2 of 355 bp, exon 3 of 289 bp and exon 4 of 741 bp (ending at tga stop codon)] and 3 introns (intron 1 of 196 bp, intron 2 of 81 bp and intron 3 of 77 bp). this conclusion was confirmed by the ... | 1994 | 7894060 |
| spectroscopic evidence for the symmetric location of tyrosines d and z in photosystem ii. | saturation-recovery epr spectroscopy has been used to probe the location of the redox-active tyrosines, yd (tyrosine 160 of the d2 polypeptide, cyanobacterial numbering) and yz (tyrosine 161 of the d1 polypeptide), relative to the non-heme fe(ii) in mn-depleted photosystem ii (psii). measurements have been made on psii membranes isolated from spinach and on psii core complexes purified from the cyanobacterium synechocystis sp. pcc 6803. in the case of synechocystis psii, site-directed mutagenesi ... | 1995 | 7893698 |
| the steady-state mrna levels for thylakoid proteins exhibit coordinate diurnal regulation. | steady-state mrna levels for thylakoid proteins were analysed in spinach cotyledons under diurnally changing light conditions. most fluctuate considerably throughout the day, while the levels of others show only low amplitude or no oscillation. levels of mrnas coding for proteins that belong to the same multiprotein complex generally oscillate in parallel and exhibit maxima that are specific for that complex: mrnas for photosystem i proteins appear prior to those for photosystem ii polypeptides ... | 1995 | 7891661 |
| immunological characterization and chloroplast localization of the tryptophan biosynthetic enzymes of the flowering plant arabidopsis thaliana. | in order to study the tryptophan biosynthetic enzymes of the plant arabidopsis thaliana, polyclonal antibodies were raised against five of the tryptophan biosynthetic pathway proteins: anthranilate synthase alpha subunit, phosphoribosylanthranilate transferase, phosphoribosylanthranilate isomerase, and the tryptophan synthase alpha and beta subunits. immunoblot analysis of arabidopsis leaf protein extracts revealed that the antibodies identify the corresponding proteins that are enriched in arab ... | 1995 | 7890741 |
| electrochemical study of the redox properties of [2fe-2s] ferredoxins. evidence for superreduction of the rieske [2fe-2s] cluster. | direct, unmediated electrochemistry has been used to compare the redox properties of [2fe-2s] clusters in spinach ferredoxin, spirulina platensis ferredoxin and the water soluble fragment of the rieske protein. the use of electrochemistry enabled, for the first time, the observation of the second reduction step, [fe(iii), fe(ii)] to [fe(ii), fe(ii)], in a biological [2fe-2s] system. a water-soluble fragment of the rieske protein from bovine heart bc1 complex exhibits two subsequent quasi-reversi ... | 1995 | 7890043 |
| expression of the betaine aldehyde dehydrogenase gene in barley in response to osmotic stress and abscisic acid. | when subjected to salt stress or drought, some vascular plants such as barley respond with an increased accumulation of the osmoprotectant glycine betaine (betaine), being the last step of betaine synthesis catalyzed by betaine aldehyde dehydrogenase (badh). we report here cloning and characterization of badh cdna from barley, a monocot, and the expression pattern of a badh transcript. an open reading frame of 1515 bp encoded a protein which showed high homology to badh enzymes present in other ... | 1995 | 7888620 |
| role of transit peptide sequence of plastocyanin for its expression, processing, and copper-binding activity in escherichia coli. | plastocyanin is a copper protein that functions as an electron carrier in the thylakoid lumen of the chloroplast. to characterize the transit peptide of plastocyanin and develop expression systems for it in escherichia coli, three kinds of expression vectors which encode different size precursor plastocyanin molecules were constructed. their expression, processing, and copper-binding activity have been examined. when the full-length cdna encoding the precursor plastocyanin from silene pratensis ... | 1994 | 7883757 |
| the 2-oxoglutarate/malate translocator of chloroplast envelope membranes: molecular cloning of a transporter containing a 12-helix motif and expression of the functional protein in yeast cells. | the 2-oxoglutarate/malate translocator of spinach chloroplasts transports carbon skeletons into chloroplasts for net glutamate synthesis. a sequence of a endoprotease lys-c peptide derived from the purified protein allowed the design of an oligonucleotide which was then used for a hybridization screening of a cdna library. a 1945 bp insert of 1 of the isolated clones codes for the entire 569 amino acid residues of the precursor protein corresponding to a molecular mass of 60,288 da. there was no ... | 1995 | 7873543 |
| structure and expression of a nitrite reductase gene from bean (phaseolus vulgaris) and promoter analysis in transgenic tobacco. | a structural gene encoding nitrite reductase (nir) in bean (phaseolus vulgaris) has been cloned and sequenced. the nir gene is present as a single copy encoding a protein of 582 amino acids. the bean nir protein is synthesized as a precursor with an amino-terminal transit peptide (tp) consisting of 18 amino acid residues. the bean nir transit peptide shows similarity to the tps of other known plant nirs. the nir gene is expressed in trifoliate leaves and in roots of 20-day old bean plants where ... | 1995 | 7865786 |
| structure and expression of the gene encoding ribosomal protein s1 from the cyanobacterium synechococcus sp. strain pcc 6301: striking sequence similarity to the chloroplast ribosomal protein cs1. | we isolated a 38 kda ssdna-binding protein from the unicellular cyanobacterium synechococcus sp. strain pcc 6301 and determined its n-terminal amino acid sequence. a genomic clone encoding the 38 kda protein was isolated by using a degenerate oligonucleotide probe based on the amino acid sequence. the nucleotide sequence and predicted amino acid sequence revealed that the 38 kda protein is 306 amino acids long and homologous to the nuclear-encoded 370 amino acid chloroplast ribosomal protein cs1 ... | 1995 | 7862084 |
| methionine biosynthesis in higher plants. ii. purification and characterization of cystathionine beta-lyase from spinach chloroplasts. | cystathionine beta-lyase, the second enzyme of the transsulfuration pathway leading to homocysteine synthesis was purified over 16,000-fold from spinach (spinacia oleracea l.) leaf chloroplasts (soluble fraction). enzyme activity was followed along the purification scheme by either a colorimetric method for the determination of cysteine or by fluorescence detection of the bimane derivative of l-homocysteine after reverse-phase hplc. cystathionine beta-lyase has a molecular mass of 170,000 +/- 50 ... | 1995 | 7840670 |
| modulation of cysteine biosynthesis in chloroplasts of transgenic tobacco overexpressing cysteine synthase [o-acetylserine(thiol)-lyase]. | cysteine synthase [o-acetyl-l-serine(thiol)-lyase, ec 4.2.99.8] (csase), which is responsible for the terminal step of cysteine biosynthesis, catalyzes the formation of l-cysteine from o-acetyl-l-serine (oas) and hydrogen sulfide. three t-dna vectors carrying a spinach (spinacia oleracea) cytoplasmic csase a cdna (k. saito, n. miura, m. yamazaki, h. horano, i. murakoshi [1992] proc natl acad sci usa 89: 8078-8082) were constructed as follows: pcsk3f, cdna driven by the cauliflower mosaic virus ( ... | 1994 | 7824657 |
| supramolecular structure of the photosystem ii complex from green plants and cyanobacteria. | photosystem ii (psii) complexes, isolated from spinach and the thermophilic cyanobacterium synechococcus elongatus, were characterized by electron microscopy and single-particle image-averaging analyses. oxygen-evolving core complexes from spinach and synechococcus having molecular masses of about 450 kda and dimensions of approximately 17.2 x 9.7 nm showed twofold symmetry indicative of a dimeric organization. confirmation of this came from image analysis of oxygen-evolving monomeric cores of p ... | 1995 | 7816811 |