Publications

nucleotide sequence of a spinach chloroplast threonine trna.	the nucleotide sequence of a spinach chloroplast threonine trna has been determined. this chloroplast threonine trna has been determined. this chloroplast threonine trna has 75 nucleotides, which is the same chain length as the recently determined threonine trna from yeast mitochondria. this contrasts with the 6 non-organelle threonine trnas sequenced to date, which are 76 nucleotides in length. however, other than this similarity in size, the chloropast trnathr has little similarlity to the yea ...	1980	7410397
crystallization and characterization of ribulose 1,5-bisphosphate carboxylase/oxygenase from eight plant species.	ribulose bisphosphate carboxylase/oxygenase was isolated and crystallized from eight plant species. crystals grew from either of two similar sets of crystallizing conditions: crystals of the enzyme from alfalfa, corn, cotton, potato, spinach, tobacco, and tomato grew from solutions containing phosphate and polyethylene glycol 6000 as a precipitant, and those from potato, tobacco (both nicotiana sylvestris and nicotiana tabacum), and tomato grew from a mixture of ammonium sulfate and phosphate. c ...	1980	7410399
studies on the kinetic mechanism of nitrate reductase from spinach (spinacea oleracea).	based on lineweaver-burk plots of the initial velocities, at different concentrations of nadh and nitrate, and product inhibition patterns, an iso ping pong bi bi steady state kinetic mechanism is proposed for the spinach nitrate reductase. this mechanism incorporates the concept that the oxidized enzyme is present in two isomeric forms.	1980	7433751
spinach calmodulin: isolation, characterization, and comparison with vertebrate calmodulins.	calmodulin is the name proposed for a multifunctional, calcium binding protein whose presence has been detected in a number of eukaryotic cells. in the studies summarized here, calmodulin has been isolated from spinach leaves (spinacea oleracea), characterized, and compared to vertebrate calmodulins. quantitative recovery data for a rapid-isolation protocol demonstrate that calmodulin is a major constituent of spinach leaves. spinach calmodulin is indistinguishable from vertebrate calmodulins in ...	1980	7459343
possible dietary protective factors in relation to the distribution of duodenal ulcer in india and bangladesh.	in india there are regions of high incidence and regions of low incidence of duodenal ulcer. rats prefed for two weeks on diets from low incidence areas developed significantly fewer rumenal ulcers after pyloric ligation than rats fed on diets from high incidence areas. the protective action was found in various individual items of food taken from the diets of low incidence areas. unrefined wheat and rice, certain pulses (black gram, green gram, horse gram), some millets (sava, kutki, ragi), soy ...	1980	7461465
adenosine 5'-diphosphate-glucose pyrophosphorylase from potato tuber. significance of the n terminus of the small subunit for catalytic properties and heat stability.	cdnas encoding the large subunit and a possibly truncated small subunit of the potato tuber (solanum tuberosum l.) adenosine 5'-diphosphate-glucose pyrophosphorylase have been expressed in escherichia coli (a.a. iglesias, g.f. barry, c. meyer, l. bloksberg, p.a. nakata, t. greene, m.j. laughlin, t.w. okita, g.m. kishore, j. preiss, j biol chem [1993] 268: 1081-1086). however, some properties of the transgenic enzyme were different from those reported for the enzyme from potato tuber. in this wor ...	1995	7480324
expression of spinach nitrite reductase in escherichia coli: site-directed mutagenesis of predicted active site amino acids.	spinach ferredoxin-nitrite reductase is a chloroplast enzyme that contains a coupled [fe4s4]-siroheme-active site and catalyzes the six-electron reduction of nitrite to ammonia. an expression system which produced enzymatically active spinach nitrite reductase (nir) in escherichia coli was developed in order to study the structure-function relationships of the coupled active site using site-directed mutagenesis. the spinach nir cdna, without the sequences encoding the chloroplast transit peptide ...	1995	7487061
tomato bushy stunt virus spread is regulated by two nested genes that function in cell-to-cell movement and host-dependent systemic invasion.	we have investigated the importance of two small nested genes (p19 and p22) located near the 3' end of the genome of tomato bushy stunt virus (tbsv) for infectivity in several hosts. our results show that both genes are dispensable for replication and transcription and that the p19 gene encodes a soluble protein, whereas the p22 gene specifies a membrane-associated protein. assays using tbsv derivatives that have the beta-glucuronidase gene substituted for the capsid protein gene demonstrate tha ...	1995	7491767
universality of energy and electron transfer processes in photosystem i.	femtosecond transient absorption spectroscopy has been used to investigate the photoinduced energy and electron transfer processes in photosystem i (ps i) particles from cyanobacteria, green algae, and higher plants. at room temperature, the kinetics observed in all three species are very similar: following 590 nm excitation, an equilibration process(es) with a 3.7-7.5 ps lifetime was observed, followed by a 19-24 ps process that is associated with trapping. in all three species long-wavelength ...	1995	7492553
the molecular chaperone mhsp72 is partially associated with the inner mitochondrial membrane both in normal and heat stressed spinacia oleracea.	the mitochondrial molecular chaperones mhsp70 and hsp60 in yeast have been shown to be essential components of the protein import and assembly machinery. using the western blotting technique and heterologous antibodies we have found that in spinach leaf mitochondria, a 72 kda protein was an analogue of the mhsp70 and a 58 kda protein, an analogue of the hsp60. surprisingly, 49% of the spinach mhsp72 was associated with the membrane. the spinach hsp58 was entirely located in the matrix. the mhsp7 ...	1995	7492968
lysine- and threonine-sensitive aspartokinase isoenzymes from spinach leaves share common antigenic determinants.	the lysine- and threonine-sensitive isoenzymes of aspartate kinase were purified to homogeneity from spinach leaves and polyclonal antibodies were raised in rabbits. the antibodies were characterized by various immunological tests like ouchterlonys-double-diffusion, titrations of the inhibition of enzyme activity and elisa. the antibodies against the lysine-sensitive isoenzyme could recognise as little as 50 ng of the pure antigen protein and that against the threonine-sensitive form could recog ...	1993	7506229
antigenic relationships between chloroplast and cytosolic fructose-1,6-bisphosphatases.	cytosolic fructose-1,6-biphosphatases (fbpase, ec 3.1.3.11) from pea (pisum sativum l. cv lincoln) and spinach (spinacia oleracea l. cv winter giant) did not cross-react by double immunodiffusion and western blotting with either of the antisera raised against the chloroplast enzyme of both species; similarly, pea and spinach chloroplast fbpases did not react with the spinach cytosolic fbpase antiserum. on the other hand, spinach and pea chloroplast fbpases showed strong cross-reactions against t ...	1994	7512735
metal dispersion and transportational activities using food crops as biomonitors.	the multielement (al, ca, cd, ce, cr, cu, fe, mg, mn, ni, pb, si, and zn) levels of various common vegetables (bean, broccoli, cabbage, cauliflower, lettuce, marrow, onion, parsnip, spinach, sprouts, sweet corn, and tomato); fruits (grape and strawberry); herbs (garlic, lemon balm, marjoram, mint, rosemary and tarragon); local pasture species and surface soils collected from a commercial garden centre located within a distance of 30 m of the london orbital motorway (m25) is presented. comparativ ...	1994	7517069
carboxyl terminus of inducible nitric oxide synthase. contribution to nadph binding and enzymatic activity.	cloning of a nitric oxide synthase (nos) from raw 264.7 mouse macrophages (xie, q.-w., cho, h. j., calaycay, j., mumford, r. a., swiderek, k. m., lee, t. d., ding, a., troso, t., and nathan, c. (1992) science 256, 225-228) yielded two sets of cdna: one with a longer coding region of 1144 amino acids, whose sequence matched that of the purified protein, and another with a shorter coding region of 1122 amino acids, in which the last 10 carboxyl-terminal amino acids differed completely from those o ...	1994	7525576
modifying actions of solvent extracts from fruit and vegetable residues on 2-amino-3-methylimidazo[4,5-f]quinoline (iq) and 2-amino-3,4-dimethylimidazo[4,5-f]quinoxaline (meiqx) induced mutagenesis in salmonella typhimurium ta 98.	the edible parts of 13 fruits--apples, apricots, bananas, blackberries, sweet cherries, red currants, white grapes, oranges, peaches, pears, plums, raspberries, and strawberries--and of 12 vegetables--asparagus, green beans, broccoli, brussels sprouts, red and white cabbage, carrots, cauliflower, onions, green peppers, spinach, and tomatoes--were squeezed in order to separate juices and residues. the residues were washed, lyophilized, and extracted sequentially with n-hexane, dichloromethane, ac ...	1995	7531289
functional conformations of calmodulin: i. preparation and characterization of a conformational specific anti-bovine calmodulin monoclonal antibody.	calmodulin, similarly to many other ca(2+)-activated proteins, undergoes considerable conformational changes in the presence of ca2+ ions. these changes were followed using specific monoclonal antibodies against calmodulin. since calmodulin is a poor immunogen due to its high phylogenetic conservancy, glutaraldehyde-crosslinked bovine brain extract, which contains a considerable amount of functionally active calmodulin complexed with its target proteins, was used as an antigen. out of nine anti- ...	1995	7541230
laser-flash kinetic analysis of the fast electron transfer from plastocyanin and cytochrome c6 to photosystem i. experimental evidence on the evolution of the reaction mechanism.	the reaction mechanism of electron transfer from the interchangeable metalloproteins plastocyanin (pc) and cytochrome c6 (cyt) to photooxidized p700 in photosystem i (psi) has been studied by laser-flash absorption spectroscopy using a number of evolutionarily differentiated organisms such as cyanobacteria (anabaena sp. pcc 7119 and synechocystis sp. pcc 6803), green algae (monoraphidium braunii), and higher plants (spinach). psi reduction by pc or cyt shows different kinetics depending on the o ...	1995	7547859
nucleotides of trna (glu) involved in recognition by barley chloroplast glutamyl-trna synthetase and glutamyl-trna reductase.	the biosynthesis of delta-aminolevulinate (ala), via the c-5 pathway, requires trna(glu) as a cofactor for the glutamyl trna(glu) synthetase and the glutamyl trna(glu) reductase which are the first two enzymes in this three step pathway. these two enzymes form a ternary complex with the trna(glu) in chlamydomonas reinhardtii suggesting that the recognition elements on the trna cofactor are different for each enzyme. chemical modification and comparative studies with trna(glu)s from a number of s ...	1995	7548209
plasma carotenoids as biomarkers of vegetable intake: the university of minnesota cancer prevention research unit feeding studies.	high vegetable intake has been associated with a decreased risk for various human cancers in epidemiological studies. carotenoids are plant compounds that may both possess chemopreventive activity and be useful biomarkers of vegetable and fruit intake. nineteen men and women were randomized into a controlled cross-over feeding study to measure the effect of vegetable intake on plasma carotenoid concentrations. participants consumed each of 4 experimental diets for 9 days. the control diet consis ...	1995	7549804
[the role of food in cholera transmission].	the spreading of cholera, from peru to other latinoamerican countries in 1991, raised questions regarding food safety, food transportation and handling. control, prevention and risks implied in food import-export were also matters of concern. we deemed it interesting to determine the viability of vibrio cholerae in wide consumption food locally. selected food had different intrinsic characteristics such as: acidity (ph), water activity (aw), chemical composition, indigenous flora and other biolo ...	1995	7565031
molecular characterization of psbw, a nuclear-encoded component of the photosystem ii reaction center complex in spinach.	we describe the isolation and characterization of cdnas encoding the precursor polypeptide of the 6.1-kda polypeptide associated with the reaction center core of the photosystem ii complex from spinach. psbw, the gene encoding this polypeptide, is present in a single copy per haploid genome. the mature polypeptide with 54 amino acid residues is characterized by a hydrophobic transmembrane segment, and, although an intrinsic membrane protein, it carries a bipartite transit peptide of 83 amino aci ...	1995	7568046
[dietary carotene intake and lung cancer among men from santiago].	aiming to assess the association between carotenes and vitamin a intake and lung cancer, a case control study was performed. sixty one male subjects with lung cancer and 61 controls paired for age, sex and smoking habits from 6 hospitals in santiago were analyzed. based on a consumption tendency enquiry, the mean weekly intake of food groups, carotenes and vitamin a was calculated, considering seasonal variations. results showed that cases consumed less "winter" vegetables than controls (chard, ...	1995	7569446
the environment of [2fe-2s] clusters in ferredoxins: the role of residue 45 probed by site-directed mutagenesis.	the biochemical and biophysical properties of the ala45ser mutant of the [2fe-2s] ferredoxin from vegetative cells of the cyanobacterium anabaena sp. 7120 are described. this novel protein, which incorporates the residue present in many higher plant ferredoxins into the analogous position of a typical cyanobacterial ferredoxin, was prepared to probe the origin of the characteristic spectrochemical and functional differences between the ferredoxins from these two sources. the variant protein was ...	1995	7577985
roles of divalent metal ions in oxidations catalyzed by recombinant cytochrome p450 3a4 and replacement of nadph--cytochrome p450 reductase with other flavoproteins, ferredoxin, and oxygen surrogates.	recombinant cytochrome p450 (p450) 3a4 was most active in nifedipine and testosterone oxidation in a system including nadph-p450 reductase, cytochrome b5 (b5), a semisynthetic phospholipid mixture plus cholate, glutathione, and mgcl2. the mgcl2 effect could be seen with high concentrations of ca2+ or sr2+ but not readily when these cations were replaced with monovalent cations. the divalent cation effect was also seen in liver microsomes. part of the basis of this effect appears to be enhanced r ...	1995	7599128
spinach leaf 70-kilodalton heat-shock cognate stabilizes bovine adrenal glucose-6-phosphate dehydrogenase in vitro without apparent stable binding.	spinach (spinacia oleracea l.) leaf tissue 70-kilodalton heat-shock cognate was purified by atp-agarose affinity and gel filtration. gel filtration of the affinity-purified protein resolved it into three forms: monomer, dimer, and oligomer. in the absence of atp, the majority of the heat-shock cognate existed as a monomeric form with lesser amounts of dimer and oligomer. addition of 3 mm atp to the purified protein, containing all three forms, converted the dimeric and monomeric forms to a high- ...	1995	7599528
cloning and expression of cdna encoding a new type of ascorbate peroxidase from spinach.	a cdna clone (sap1) encoding a peroxidase was isolated from a spinach cdna library using monoclonal antibodies raised against euglena ascorbate peroxidase. the deduced amino acid sequence of sap1 had higher homology with the cytosolic ascorbate peroxidases from plant sources than with bacterial peroxidases and classical plant peroxidases. the peroxidase activity of recombinant sap1 protein expressed in e. coli was 1.6-fold higher with ascorbate than with guaiacol, which was similar to those of e ...	1995	7601279
the expression of nuclear genes encoding plastid ribosomal proteins precedes the expression of chloroplast genes during early phases of chloroplast development.	the development of different plant organs (root, hypocotyl, and cotyledons) during seed germination is connected with the transformation of proplastids, which are found in embryonic and meristematic tissues, into amyloplasts in root tissues and into chloroplasts in cotyledons. we have analyzed the expression of nuclear and plastid genes coding for the plastid translational apparatus during the first 7 d of spinacia oleracea development. results show that the nuclear genes (rps1, rps22, rpi21, an ...	1995	7610166
a subunit interaction in chloroplast atp synthase determined by genetic complementation between chloroplast and bacterial atp synthase genes.	f1f0-atp synthases utilize protein conformational changes induced by a transmembrane proton gradient to synthesize atp. the allosteric cooperativity of these multisubunit enzymes presumably requires numerous protein-protein interactions within the enzyme complex. to correlate known in vitro changes in subunit structure with in vivo allosteric interactions, we introduced the beta subunit of spinach chloroplast coupling factor 1 atp into a bacterial f1 atp synthase. a cloned atpb gene, encoding th ...	1995	7615507
a nuclear-encoded subunit of the photosystem ii reaction center.	a nuclear-encoded polypeptide of 6.1 kda was identified in isolated photosystem ii (psii) reaction center from spinacia oleracea. the hydrophobic membrane protein easily escapes staining procedures such as coomassie r-250 or silver staining, but it is clearly detected by immunodecoration with peptide-directed igg. this additional subunit was found to be present in psii reaction centers previously known to contain only the d1/d2/cytb559 proteins and the psbi gene product. furthermore, cross-linki ...	1995	7615565
laser flash absorption spectroscopy study of ferredoxin reduction by photosystem i: spectral and kinetic evidence for the existence of several photosystem i-ferredoxin complexes.	the existence of three first-order phases has been previously reported for the reduction of soluble ferredoxin by photosystem i (psi), both from the cyanobacterium synechocystis sp. pcc 6803 (at ph 8 and in the presence of salts) [sétif, p. q. y., & bottin, h. (1994) biochemistry 33, 8495-8504]. the spectra of these three phases (t1/2 < 1 microsecond, = 13-20 and 103-123 microseconds) have been measured between 460 and 600 nm. all of them are fully consistent with electron transfer from (fa,fb)- ...	1995	7619805
direct electrochemistry and epr spectroscopy of spinach ferredoxin mutants with modified electron transfer properties.	mutations of the conserved residue glu-92 to lysine, glutamine, and alanine have been performed in the recombinant ferredoxin i of spinach leaves. the purified ferredoxin mutants were found twice as active with respect to wild-type protein in the nadph-cytochrome c reductase reaction catalyzed by ferredoxin-nadp+ reductase in the presence of ferredoxin. cyclic voltammetry and epr measurements showed that the mutations cause a change in the [2fe-2s] cluster geometry, whose redox potential becomes ...	1995	7628609
[binding of pcb by several types of dietary fiber in vivo and in vitro].	we investigated the binding of pcb by dietary fiber in vivo and in vitro. forty male rats consisting of four rats a group were housed and rats of each group were given a treatment diet containing rice-bran fiber, spinach fiber, burdock fiber, cabbage fiber, soybean fiber japanese-radish fiber, carrot fiber, corn fiber and cellulose for five days. the remaining four rats were fed a non-fiber diet as controls. the animals were administered with 0.5 ml of the race-bran oil used by yusho patients an ...	1995	7628811
[effect of dietary fiber on fecal excretion and liver distribution of pcdf in rats].	forty male rats (126 g body weight) consisting of four rats a group were housed and rats of each group were given a treatment diets containing cellulose, rice-bran fiber, spinach fiber, burdock fiber, cabbage fiber, soybean fiber, japanese-radish fiber, carrot fiber and corn fiber for five days. the remaining four rats were fed a non-fiber diet as controls. the animals were orally administered with 0.5 ml of the rice-bran oil used by yusho patients and kept on the same diets for five days. the r ...	1995	7628812
isolation and characterization of a cdna encoding the seca protein from spinach chloroplasts. evidence for azide resistance of sec-dependent protein translocation across thylakoid membranes in spinach.	thylakoid membranes of chloroplasts in higher plants harbor different pathways for the translocation of proteins. one of these routes is related to the prokaryotic sec pathway, which mediates the secretion of particular proteins into the periplasmic space and involves the seca protein as an essential component. we have isolated a full size cdna of 3739 nucleotides encoding the seca homologue from spinach. it contains an open reading frame of 1036 codons corresponding to a polypeptide with a calc ...	1995	7629156
phosphorylation of a chloroplast rna-binding protein changes its affinity to rna.	an rna-binding protein of 28 kda (28rnp) was previously isolated from spinach chloroplasts and found to be required for 3' end-processing of chloroplast mrnas. the amino acid sequence of 28rnp revealed two approximately 80 amino-acid rna-binding domains, as well as an acidic- and glycine-rich amino terminal domain. upon analysis of the rna-binding properties of the 'native' 28rnp in comparison to the recombinant bacterial expressed protein, differences were detected in the affinity to some chlor ...	1995	7630729
site-specific mutagenesis demonstrates that the structural requirements for efficient electron transfer in anabaena ferredoxin and flavodoxin are highly dependent on the reaction partner: kinetic studies with photosystem i, ferredoxin:nadp+ reductase, and cytochrome c.	electron transfer reactions involving site-specific mutants of anabaena ferredoxin (fd) and flavodoxin (fld) modified at surface residues close to the prosthetic groups, with photoexcited p700 in spinach photosystem i (psi) particles, ferredoxin:nadp+ reductase (fnr), and horse cytochrome c (cytc), have been investigated by laser flash photolysis and stopped-flow spectrophotometry. nonconservative mutations in fd at f65 and e94, which have been shown to result in very large inhibitions of electr ...	1995	7639526
characterization of the substrate specificity of sucrose-phosphate synthase protein kinase.	sucrose-phosphate synthase (sps; ec 2.4.1.14) is regulated by reversible protein phosphorylation. when the enzyme is phosphorylated it is inactivated and can be reactivated by removal of phosphate. the major regulatory phosphorylation site is known to be ser158 in the spinach-leaf enzyme, and two protein kinase activities have been resolved chromatographically which phosphorylate sps at this site in vitro. in this report, we use a set of synthetic peptide substrate analogs based on the phosphory ...	1995	7639538
trial of a new medium-term model using benzo(a)pyrene induced lung tumor in newborn mice.	a new medium-term in vivo model was tried using pulmonary adenoma induced by benzo(a)pyrene (bp) in newborn mice. both inbred mice such as c57bl/5j, c57br/cdj. a/j mice and non inbred n:gp(s) mice were used. benzo(a)pyrene was injected in the subscapular region of newborn mice within 24 hours after birth at a dose of 0.5 mg and 1 mg per mouse, respectively. after 9 weeks lung tumor induced in n:gp(s) and a/j mice but in the other mice. the dose showing a 50% tumor incidence was found in n:gp(s) ...	1995	7645968
cis-acting elements and expression pattern of the spinach rps22 gene coding for a plastid-specific ribosomal protein.	in order to study the regulation of nuclear genes coding for plastid ribosomal proteins, we have analysed the promoter region of spinach rps22 using both in vitro and in vivo approaches. by footprinting analyses, we have identified eight dna elements interacting with spinach leaf nuclear factors in the 300 bp promoter region upstream of the transcription start site. among these elements, four are short at-rich sequences and one is identical to the hex motif characterized initially in wheat histo ...	1995	7647293
identification and localization of the first glutaredoxin in leaves of a higher plant.	glutaredoxin(thioltransferase) has been identified and purified to homogeneity from spinach leaves. its cytosolic localization was demonstrated by chromatographic and immunological analysis of extracts from isolated spinach chloroplasts and mitochondria, respectively. spinach glutaredoxin shows a significant crossreactivity with antibodies raised against e. coli glutaredoxin and possesses a specific thioltransferase activity comparable to that of the e. coli protein. minor thioltransferase activ ...	1995	7649248
evidence for a novel atp-dependent membrane-associated protease in spinach leaf mitochondria.	we report the presence of an atp-dependent proteolytic activity in spinach (spinacia oleracea) leaf mitochondria. the proteolysis was observed as degradation of newly imported precursor protein. the precursor studied was that of the atp synthase f1 beta subunit of nicotiana plumbaginifolia, transcribed and translated in vitro. degradation of pre-f1 beta was observed during kinetic studies of import in vitro. the degradation was characterized in chase experiments in which the precursor was import ...	1995	7654191
spinach ferredoxin i: overproduction in escherichia coli and purification.	ferredoxin i is the most abundant form of photosynthetic-type ferredoxin present in spinach chloroplasts. a cdna clone encoding the precursor of spinach ferredoxin i has been engineered to synthesize the mature form of the plant protein in escherichia coli. among several different plasmid constructions, the expression system based on phage t7 promoter (vector pet-11d) was found to be the most efficient for spinach ferredoxin overproduction. upon induction, ferredoxin i accounted for about 2.5% o ...	1995	7663165
aldehyde dehydrogenase-derived omega-crystallins of squid and octopus. specialization for lens expression.	omega-crystallin of the octopus lens is related to aldehyde dehydrogenases (aldh) of vertebrates (tomarev, s. i., zinovieva, r. d., and piatigorsky, j. (1991) j. biol. chem. 266, 24226-24231) and aldh1/eta-crystallin of elephant shrews (wistow, g., and kim, h. (1991) j. mol. evol. 32, 262-269). only very low amounts of omega-crystallin are present in the squid lens. here, we have cloned omega-crystallin cdnas of the octopus (octopus dofleini) and squid (ommastrephes sloani pacificus) lenses. the ...	1993	7684383
crystal structure of spinach chloroplast fructose-1,6-bisphosphatase at 2.8 a resolution.	the three-dimensional structure of the spinach chloroplast fructose-1,6-bisphosphatase (fru-1,6-pase) has been solved by the molecular replacement method at 2.8 a resolution and refined to a crystallographic r factor of 0.203. the enzyme is composed of four monomers and displays pseudo d2 symmetry. comparison with the allosteric fru-1,6-pase from pig kidney shows orientationally displaced dimers within the quaternary structure of the chloroplast enzyme. when the c1c2 dimers of the two enzymes ar ...	1995	7703243
accurate determination of cobalt traces in several biological reference materials.	a newly devised, very accurate ("definitive") method for the determination of trace amounts of cobalt in biological materials was validated by the analysis of several certified reference materials. the method is based on a combination of neutron activation and selective and quantitative postirradiation isolation of radiocobalt from practically all other radionuclides by ion-exchange and extraction chromatography followed by gamma-ray spectrometric measurement. the significance of criteria that s ...	1994	7710879
charge recombination reactions in photosystem ii. i. yields, recombination pathways, and kinetics of the primary pair.	recombination reactions of the primary radical pair in photosystem ii (ps ii) have been studied in the nanosecond to millisecond time scales by flash absorption spectroscopy. samples in which the first quinone acceptor (qa) was in the semiquinone form (qa-) or in the doubly reduced state (presumably qah2) were used. the redox state of qa and the long-lived triplet state of the primary electron donor chlorophyll (3p680) were monitored by epr. the following results were obtained at cryogenic tempe ...	1995	7718587
charge recombination reactions in photosystem ii. 2. transient absorbance difference spectra and their temperature dependence.	absorbance difference spectra of the transient states in photosystem ii (ps ii) have been examined in the qv absorption region between 660 and 700 nm. the p680+pheo-/p680pheo, 3p680/p680, and p680+qa-/p680qa spectra were measured in o2-evolving ps ii core complexes from synechococcus and ps ii-enriched membrane fragments from spinach. the low-temperature absorbance difference spectra vary only slightly between both ps ii preparations. the 3p680/p680 spectrum is characterized by a bleaching at 68 ...	1995	7718588
sensitization of calcium-induced calcium release by cyclic adp-ribose and calmodulin.	cyclic adp-ribose (cadpr) is emerging as an endogenous regulator of ca2+-induced ca2+ release (cicr), and we have recently demonstrated that its action is mediated by calmodulin (cam) (lee, h. c., aarhus, r., graeff, r., gurnack, m. e., and walseth, t. f. (1994) nature 370, 307-309). in this study we show by immunoblot analyses that the protein factor in sea urchin eggs responsible for conferring cadpr sensitivity to egg microsomes was cam. this was further supported by the fact that bovine cam ...	1995	7721819
existence of two ferredoxin-glutamate synthases in the cyanobacterium synechocystis sp. pcc 6803. isolation and insertional inactivation of gltb and glts genes.	the first two genes of ferredoxin-dependent glutamate synthase (fd-gogat) from a prokaryotic organism, the cyanobacterium synechocystis sp. pcc 6803, were cloned in escherichia coli. partial sequencing of the cloned genomic dna, of the 6.3 kb hind iii and 9.3 kb cla i fragments, confirmed the existence of two different genes coding for glutamate synthases, named gltb and glts. the gltb gene was completely sequenced and encodes for a polypeptide of 1550 amino acid residues (m(r) 168,964). compara ...	1995	7727752
spinach chloroplast cpn21 co-chaperonin possesses two functional domains fused together in a toroidal structure and exhibits nucleotide-dependent binding to plastid chaperonin 60.	chloroplasts contain a 21-kda co-chaperonin polypeptide (cpn21) formed by two groes-like domains fused together in tandem. expression of a double-domain spinach cpn21 in escherichia coli groes mutant strains supports growth of bacteriophages lambda and t5, and will also suppress a temperature-sensitive growth phenotype of a groes619 strain. each domain of cpn21 expressed separately can function independently to support bacteriophage lambda growth, and the n-terminal domain will additionally supp ...	1995	7738007
protein histidine phosphatase activity in rat liver and spinach leaves.	whole cell extracts from rat liver or spinach leaves contain divalent ion-independent protein histidine phosphatase activity due to phosphatases of the pp1/pp2a family. in the rat liver extract, almost all the activity was found in the pp1, pp2a1 and pp2a2 peaks. in the spinach leaf extract, four phosphorylase phosphatase activity peaks were resolved--three containing pp1 and one containing pp2a--and all showed histidine phosphatase activity. thus, protein histidine phosphatase activity is expre ...	1995	7750542
expression in escherichia coli of the extrinsic 18-kda protein of photosystem ii of spinach.	a cdna encoding the precursor for the 18-kda protein of psii of spinach was expressed in escherichia coli. when the cell lysate was incubated at 7 degrees c, the precursor was degraded by proteases of e. coli to a polypeptide of 18 kda (p18) that consisted of the mature protein moiety plus the last four residues of the transit peptide. p18 was able to reconstitute the water-oxidizing complex of nacl-treated psii membranes supplemented with the 23-kda protein. moreover, p18 was cleaved by the pro ...	1995	7757336
purification, cloning and expression of spinach leaf sucrose-phosphate synthase in escherichia coli.	sucrose-phosphate synthase (sps) from leaves of spinach (spinacia oleracea l.) has been purified to homogeneity by a procedure involving precipitation with polyethylene glycol and chromatography over diethylaminoethylcellulose, omega-aminohexyl-agarose, mono q and blue affinity columns. the purification factor was 838 and the final specific activity was 1.3 nkat.(mg protein)-1. on denaturing gels the major polypeptide was 120 kda but there was also a variable amount of smaller polypeptides in th ...	1993	7763376
cloning and developmental expression of the sucrose-phosphate-synthase gene from spinach.	a 561-base-pair (bp) polymerase-chain-reaction (pcr) product of sucrose-phosphate synthase (sps) was amplified using degenerate oligonucleotide primers corresponding to tryptic peptides of sps (ec 2.4.1.14) from spinach (spinacia oleracea l). crucial to the primer specificity and the synthesis of the 561-bp product was the use of primer pools in which the number of degenerate primer species was limited. a full-length cdna was subsequently obtained by screening a cdna bacteriophage library with t ...	1993	7763823
metabolic engineering of glycine betaine synthesis: plant betaine aldehyde dehydrogenases lacking typical transit peptides are targeted to tobacco chloroplasts where they confer betaine aldehyde resistance.	certain higher plants synthesize and accumulate glycine betaine, a compound with osmoprotectant properties. biosynthesis of glycine betaine proceeds via the pathway choline-->betaine aldehyde-->glycine betaine. plants such as tobacco (nicotiana tabacum l.) which do not accumulate glycine betaine lack the enzymes catalyzing both reactions. as a step towards engineering glycine betaine accumulation into a non-accumulator, spinach and sugar beet complementary-dna sequences encoding the second enzym ...	1994	7764986
identification of potential redox-sensitive cysteines in cytosolic forms of fructosebisphosphatase and glyceraldehyde-3-phosphate dehydrogenase.	tertiary-structure modeling suggests the occurrence of disulfide bonds in the cytosolic form of fructose-bisphosphatase (ec 3.1.3.11) in spinach (spinacia oleracea l.), sugarbeet (beta vulgaris l.) and potato (solanum tuberosum l.). redox modulation could then control the amp sensitivity of fructosebisphosphatase in the cytosol, as suggested by the experiments of e. khayat et al. (1993, plant physiol. 101, 57-64). modeling also reveals two cysteine residues correctly positioned to form a disulfi ...	1995	7767233
ca(2+)-dependent protein switches in actomyosin based contractile systems.	myosin is an atpase enzyme with the unique property that the hydrolysis and release of pi and adp is coupled to movement via a cyclic interaction between myosin and actin filaments. recent evidence indicates that for all myosin and myosin-like molecules, from slime mould and spinach vacuole to man, the mechanism of the molecular motor is essentially the same. it is now appropriate to ask general questions about how these motors are regulated by ca2+. is regulation the same throughout nature or a ...	1995	7767791
cloning and expression analysis of sucrose-phosphate synthase from sugar beet (beta vulgaris l.).	a cdna clone encoding a sucrose-phosphate synthase from sugar beet (bvsps 1) has been isolated by screening a tap root-specific cdna library using a heterologous sps cdna from spinach. the 3635 bp sugar beet cdna codes for a 1045 amino acid polypeptide with a predicted molecular mass of 118 kda. the deduced amino acid sequence of sugar beet sps shows homologies with sps from maize (71% identity) and spinach (77% identity). genomic southern blot analysis suggests that bvsps 1 is a low-copy-number ...	1995	7770061
[the content of nitrates and nitrites in fruits, vegetables and other foodstuffs].	there are presented the results of the investigation of many popular fresh and frozen vegetables as well as in fresh and frozen fruits, such as different kind of apples, strawberries, currants, raspberries and many other tender fruits mainly from market and few from own allotment-cottages performed in the year 1989-1992. the nitrate and nitrite was determined according to the griess reaction. high levels of nitrate was encountered in lettuce, frozen spinach, fennel, radishes, parsley. many of th ...	1994	7777773
calreticulin is the major ca2+ storage protein in the endoplasmic reticulum of the pea plant (pisum sativum).	a 56kda protein with high similarity in its n-terminal amino acid sequence to animal calreticulin and 100% homology with the n-terminal amino acids of spinach calreticulin has been identified in seeds of the pea plant (pisum sativum). a new purification procedure is described by which the calreticulin-like protein was selectively solubilized by incubation with deoxycholate and hgcl2 from microsomes enriched for endoplasmic reticulum. following mono q ion exchange chromatography of the deoxychola ...	1995	7779109
interaction of the 33-kda extrinsic protein with photosystem ii: identification of domains on the 33-kda protein that are shielded from nhs-biotinylation by photosystem ii.	the structural association of the spinach 33-kda extrinsic protein of photosystem ii with the membrane-bound components of the photosystem was investigated by labeling the 33-kda extrinsic protein with the amino group-specific reagent n-hydroxysuccinimidobiotin both on nacl-washed photosystem ii membranes and free in solution. after quenching of the labeling reagent and isolation of the biotinylated molecules, the biotinylation sites were identified by staphylococcus v8 protease digestion and an ...	1995	7779793
biosynthesis and distribution of insect-molting hormones in plants--a review.	insect-molting hormones, phytoecdysteroids, have been reported to occur in over 100 plant families. plants, unlike insects, are capable of the biosynthesis of ecdysteroids from mevalonic acid, and in several cases the biosynthesis of phytoecdysteroids was also demonstrated to proceed via sterols. spinacia oleracea (spinach) biosynthesizes polypodine b and 20-hydroxyecdysone, which is the predominant insect-molting hormone found in plant species. the onset of ecdysteroid production in spinach req ...	1995	7791535
purification and characterization of an nadh-hexacyanoferrate(iii) reductase from spinach leaf plasma membrane.	plasma membranes were purified from spinach (spinacea oleracea l.) leaves by aqueous two-phase partitioning. the nadh-hexacyanoferrate(iii) reductase was released from the membrane by chaps solubilization and purified 360-fold by ion-exchange chromatography followed by affinity chromatography and size-exclusion chromatography on fplc. a major band of 45 kda and a minor contaminant of 66 kda were detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (sds-page). the band at 45 kda ...	1995	7793986
dietary factors and stomach cancer: a case-control study in korea.	stomach cancer is the most common cancer among koreans. there is wide agreement that dietary factors are important in gastric carcinogenesis, but the role of many korean food items remains unknown.	1995	7797354
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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 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
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
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
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
cdna sequence for the plastidic phosphoglucomutase from spinacia oleracea (l.).		1994	7972501