| [electron microscopic data on the mesosomelike and myelinlike structures of blue-green algae]. | the mesosome-like structures of blue-green algae were studied by freeze-etching without preliminary fixation and, in parallel, by a technique of ultrathin sections. these structures were found mainly in synechococcus elongatus and synechocystis aquatilis, less often, in anacystis nidulans and anabaena variabilis, and were not detected in plectonema boryanum. the following types of membrane structures were encountered: (1) formation consisting of three- and five-layered membranes and resembling t ... | 1978 | 212674 |
| amino and carboxy terminal sequences of the dna-binding protein hu from the cyanobacterium synechocystis pcc 6701 (atcc 27170). | | 1979 | 229851 |
| f0-f1-type atpase is not light-regulated in vivo in the cyanobacterium synechocystis pcc 6803. | | 1992 | 1330768 |
| cloning and nucleotide sequence of a frxc-orf469 gene cluster of synechocystis pcc6803: conservation with liverwort chloroplast frxc-orf465 and nif operon. | a gene, frxc, which is unique to the chloroplast genome of the liverwort marchantia polymorpha, has sequence similarity to nifh, the product of which is an iron protein of a nitrogenase. although frxc is expressed to produce a protein in liverwort chloroplasts, its function is not known. using a probe of liverwort chloroplast dna, a 10.1-kb region containing a gene cluster consisting of open reading frames (orf278-frxc-orf469-orf248) was isolated from the cyanobacterium synechocystis pcc6803. in ... | 1992 | 1368342 |
| gene encoding a putative zinc finger protein in synechocystis pcc6803. | a 5.5-kb hindiii fragment of synechocystis pcc6803 containing a liverwort (orf316) homolog encoding a putative zinc finger protein was cloned. nucleotide sequence analysis showed that the homology of the amino acid sequence deduced from the orf326 of synechocystis pcc6803 with the counterparts of a liverwort and tobacco was 50% and 46%, respectively. synechocystis orf326 also showed 38% homology with the dedb gene in escherichia coli. the gene organization of the region in these species of organ ... | 1991 | 1368738 |
| multiple rpod-related genes of cyanobacteria. | genomes of many eubacterial strains have been shown to encode for multiple rpod-related genes. in this report, we describe the identification of the multiple rpod-related genes of cyanobacterial strains. dnas of three cyanobacterial strains, anabaena sp. pcc7120, synechococcus sp. pcc7942, and synechocystis sp. pcc6803, were examined by southern hybridization, using a synthetic probe designed for detecting rpod or rpod-related genes. four or five hybridization signals were found in each dna. fou ... | 1992 | 1368828 |
| complex formation between glutamyl-trna synthetase and glutamyl-trna reductase during the trna-dependent synthesis of 5-aminolevulinic acid in chlamydomonas reinhardtii. | the formation of a stable complex between glutamyl-trna synthetase and the first enzyme of chlorophyll biosynthesis glutamyl-trna reductase was investigated in the green alga chlamydomonas reinhardtii. apparently homogenous enzymes, purified after previously established purification protocols were incubated in various combinations with atp, glutamate, trna(glu) and nadph and formed complexes were isolated via glycerol gradient centrifugation. stable complexes were detected only after the preincu ... | 1992 | 1451806 |
| structure and expression of a cyanobacterial ilvc gene encoding acetohydroxyacid isomeroreductase. | acetohydroxyacid isomeroreductase (ahair) is the shared second enzyme in the biosynthetic pathways leading to isoleucine and valine. ahair is encoded by the ilvc gene in bacteria. a 1,544-bp fragment of genomic dna containing the ilvc gene was cloned from the cyanobacterium synechocystis sp. strain pcc 6803, and the complete nucleotide sequence was determined. the identity of the gene was established by comparison of the nucleotide and derived peptide sequences with those of other ilvc genes. th ... | 1992 | 1459938 |
| cloning and transcription analysis of the ndh(a-i-g-e) gene cluster and the ndhd gene of the cyanobacterium synechocystis sp. pcc6803. | the plastid dna of higher plants contains eleven reading frames that are homologous to subunits of the mitochondrial nadh-ubiquinone oxidoreductase (complex i). the genes are expressed, but a plastid nad(p)h dehydrogenase has not yet been isolated and the function of the enzyme in plastid metabolism is unknown. cyanobacteria also contain a nadh dehydrogenase that is homologous to the mitochondrial complex i. the enzyme is sensitive to rotenone and is located on the cytoplasmic and the thylakoid ... | 1992 | 1463844 |
| restoration of the wild-type locus in an rubp carboxylase/oxygenase mutant of synechocystis pcc 6803 via targeted gene recombination. | the interaction between homologous dna sequences, distant from each other in the chromosome, was examined in the cyanobacterium synechocystis pcc 6803. most of the rbcl gene encoding the large subunit of ribulose bisphosphate carboxylase/oxygenase (rubisco) was duplicated in the genome by a targeted insertion of a 3'-truncated gene copy into the psb a-i locus. both rbcl genes, in the psb a-i region and at the rbc locus, were non-functional; the former due to the 3' truncation, and the latter due ... | 1992 | 1465099 |
| the psac genes of synechococcus sp. pcc7002 and cyanophora paradoxa: cloning and sequence analysis. | the psac genes of the cyanobacterium, synechococcus sp. pcc7002, and of the cyanelle genome of the phylogenetically ambiguous biflagellate, cyanophora paradoxa, were cloned, mapped and sequenced. the psac proteins of both species exhibit high degrees (approx. 95%) of sequence similarity to the psac proteins of other cyanobacteria as well as the chloroplast-encoded proteins of green algae and higher plants. the synechococcus sp. pcc7002 psac gene is transcribed as a monocistronic mrna of approx. ... | 1992 | 1551590 |
| glutamyl-trna reductase from escherichia coli and synechocystis 6803. gene structure and expression. | in the cyanobacterium synechocystis sp. pcc 6803 and in the enterobacterium escherichia coli delta-amino-levulinic acid (ala) is formed from glutamyl-trna by the sequential action of two enzymes, glutamyl-trna reductase (glutr) and glutamate-1-semialdehyde aminotransferase. e. coli has two glutr proteins with sizes of 45 kda (glutr45) and 85 kda (glutr85) (jahn, d., michelsen, u., and söll, d. (1991) j. biol. chem. 266, 2542-2548). the hema gene, isolated from e. coli and several other eubacteri ... | 1992 | 1569081 |
| nucleotide sequence of the phytoene desaturase gene from synechocystis sp. pcc 6803 and characterization of a new mutation which confers resistance to the herbicide norflurazon. | | 1992 | 1581575 |
| heat shock hsp70 protein is chloroplast-encoded in the chromophytic alga pavlova lutherii. | heat shock proteins are ubiquitous and highly conserved. recently they have become implicated in the import of proteins into organelles. all the heat shock genes characterized to date, however, are known or assumed to be encoded in the nuclear genome even if the corresponding protein can be localised in the mitochondrion or chloroplast. in contrast, we identify here an hsp70 gene in the unicellular chromophytic alga pavlova lutherii which is located on the chloroplast genome. localisation of thi ... | 1992 | 1536924 |
| purification, characterization and function of bacterioferritin from the cyanobacterium synechocystis p.c.c. 6803. | storage and buffering of iron is achieved by a class of proteins, the ferritins, widely distributed throughout the living kingdoms. all ferritins have in common their three-dimensional structure and their ability to store large amounts of iron in their central cavity. however, eukaryotic ferritins from plants and animals and bacterioferritins have no sequence similarity, and besides non-haem iron bacterioferritins contain haem residues whereas eukaryotic ferritins do not. in this paper we report ... | 1992 | 1536655 |
| the d1 protein of the photosystem ii reaction-centre complex accumulates in the absence of d2: analysis of a mutant of the cyanobacterium synechocystis sp. pcc 6803 lacking cytochrome b559. | the reaction center core of photosystem ii, a multiprotein membrane bound complex, is composed of a heterodimer of two proteins, d1 and d2. a random mutagenesis technique was used to isolate a photosystem ii deficient mutant, cp6t16, of the unicellular cyanobacterium, synechocystis sp. pcc 6803. nucleotide sequence analysis showed that the primary lesion in cp6t16 is an ochre mutation introducing a translational stop codon in the psbe gene, encoding the alpha-subunit of cytochrome b559, an integ ... | 1992 | 1602969 |
| localization and distribution of hopanoids in membrane systems of the cyanobacterium synechocystis pcc 6714. | intracellular localization of triterpenic membrane stabilizers of the hopane series is described for the first time for a cyanobacterium. in synechocystis pcc 6714, a bacteriohopanetetrol derivative (main compound) and diplopterol were detected in cell wall (cw) and thylakoid membrane (tm). both hopanoids were enriched 4.5-fold and 9.0-fold in cw and outer membrane (om) fractions, respectively, compared to tms. | 1992 | 1624128 |
| oxygen yield and thermoluminescence characteristics of a cyanobacterium lacking the manganese-stabilizing protein of photosystem ii. | previous experiments have shown that a synechocystis sp. pcc 6803 mutant (delta psbo) lacking the extrinsic manganese-stabilizing protein (msp) exhibits impaired, but significant levels of h2o-splitting activity [burnap, r., & sherman, l.a. (1991) biochemistry 30, 440-446]. [14c]dcmu-binding experiments now show that the number and affinity of dcmu-binding sites (normalized to chlorophyll) are equivalent in delta psbo and the wild type, suggesting equal concentrations of assembled reaction cente ... | 1992 | 1510930 |
| mutations in the d1 subunit of photosystem ii distinguish between quinone and herbicide binding sites. | the structure-activity relationships of the plastoquinone qb binding domain in the d1 subunit of photosystem ii (psii) were investigated by characterization of mutations introduced in the d1 protein. eight novel point mutations in the gene psba, which encodes d1, were generated in the cyanobacterium synechocystis pcc6803 by site-specific mutagenesis in vitro. the effects of the resulting modifications in d1 on electron transfer in psii and on herbicide binding were analyzed. the results extend t ... | 1992 | 1498597 |
| identification of a second psac gene in the cyanobacterium synechocystis sp. pcc6803. | the psac gene encodes the 9 kda protein subunit of photosystem i that carries the iron-sulfur centers fa and fb. the paper describes the sequence and transcription analysis of a second psac gene (psac2) from synechocystis sp. pcc6803. thepsac2 gene is transcribed into an abundant monocistronic mrna. the deduced amino acid sequence of psi-c2 is very similar to the protein sequences from two other cyanobacteria (synechococcus sp. pcc7002 and nostoc sp. pcc8009). in contrast, the recently isolated ... | 1992 | 1463835 |
| identification of a hema gene from synechocystis by complementation of an e. coli hema mutant. | | 1992 | 1459859 |
| site-directed mutagenesis of the cpa-1 protein of photosystem ii: alteration of the basic residue pair 384,385r to 384,385g leads to a defect associated with the oxygen-evolving complex. | the psbb gene encodes the intrinsic chlorophyll-a binding protein cpa-1 (cp-47), a component of photosystem ii in higher plants, algae, and cyanobacteria. oligonucleotide-directed mutagenesis was used to introduce mutations into a segment of the psbb gene encoding the large extrinsic loop region of cpa-1 in the cyanobacterium synechocystis sp. pcc 6803. altered psbb genes were introduced into a mutant recipient strain (del-1) of synechocystis in which the genomic psbb gene had been partially del ... | 1992 | 1445882 |
| photosystem ii function and integrity in spite of drastic protein changes in a conserved region of the d2 protein. | d1 and d2 are structurally related proteins forming the core of the photosystem ii reaction center. the two proteins have several loop regions including an extended stroma-exposed loop between transmembrane helix d and parallel helix de. this loop (the d-de loop) is phylogenetically conserved in both proteins. the role of the d-de loop in photosystem ii was studied in synechocystis sp. pcc 6803 by constructing a chimeric d2 protein in which the stroma-exposed loop of d1 replaced that of d2. in o ... | 1992 | 1445845 |
| selection of cyanobacteria isolated from mosquito breeding sites as a potential food source for mosquito larvae. | one way to increase the persistence of larvicidal toxins in mosquito breeding sites is to clone the corresponding genes in microorganisms, such as cyanobacteria, which could serve as a source of food for the larvae. we isolated and cultured 10 strains of cyanobacteria from three mosquito breeding sites along the french mediterranean coast. most of the strains were tolerant to a relatively wide range of salt concentrations, and all of them were totally or partially resistant to at least four of t ... | 1991 | 1677241 |
| in vitro reactivation of in vivo ammonium-inactivated glutamine synthetase from synechocystis sp. pcc 6803. | glutamine synthetase from synechocystis sp. strain pcc 6803 is inactivated by ammonium addition to cells growing with nitrate as the nitrogen source. the enzyme can be reactivated in vitro by different methods such as alkaline phosphatase treatment, but not phosphodiesterase, by raising the ph of the crude extract to values higher than 8, by increasing the ionic strength of the cell-free extract, or by preincubation with organic solvents, such as 2-propanol and ethanol. these results suggest tha ... | 1991 | 1684495 |
| construction and characterization of cyanobacterial mutants lacking the manganese-stabilizing polypeptide of photosystem ii. | mutants of the cyanobacterium synechocystis sp. pasteur culture collection (pcc) 6803 that specifically lack the extrinsic 33-kda manganese-stabilizing polypeptide of the photosystem ii oxygen-evolving complex have been constructed by two independent methods. cartridge mutagenesis was used to insertionally inactivate the psbo gene of one mutant and completely delete the psbo gene of the other mutant. these mutants have no detectable manganese-stabilizing polypeptide, but they do accumulate stead ... | 1991 | 1712783 |
| photosynthetic electron transport controls degradation but not production of psba transcripts in the cyanobacterium synechocystis 6803. | accumulation and stability of psba and rbcl-s transcripts in synechocystis 6803 was followed in the presence and absence of the photosynthesis inhibitors dcmu and methylviologen. our results demonstrate that both transcript production and transcript stability are important regulatory elements for psba gene expression in synechocystis 6803. the production of psba transcripts was stimulated by light in a process that operated independently of the photosynthetic electron transport. however, stabili ... | 1991 | 1713480 |
| excitation energy transfer from phycocyanin to chlorophyll in an apca-defective mutant of synechocystis sp. pcc 6803. | a greenish mutant of the normally blue-green cyanobacterium synechocystis sp. pcc 6803, designated uv6p, has been isolated and characterized. uv6p possesses functional photosystems i and ii (psi and psii) but lacks normal light harvesting phycobilisomes because allophycocyanin is absent and core-specific linker proteins are almost entirely absent. the mutation responsible for the uv6p phenotype has been identified; it is a base substitution which results in the creation of a termination codon wi ... | 1992 | 1429645 |
| role of the carboxy terminus of polypeptide d1 in the assembly of a functional water-oxidizing manganese cluster in photosystem ii of the cyanobacterium synechocystis sp. pcc 6803: assembly requires a free carboxyl group at c-terminal position 344. | the d1 polypeptide of the photosystem ii (psii) reaction center is synthesized as a precursor polypeptide which is posttranslationally processed at the carboxy terminus. it has been shown in spinach that such processing removes nine amino acids, leaving ala344 as the c-terminal residue [takahashi, m., shiraishi, t., & asada, k. (1988) febs lett. 240, 6-8; takahashi, y., nakane, h., kojima, h., & satoh, k. (1990) plant cell physiol. 31, 273-280]. we show here that processing on the carboxy side o ... | 1992 | 1420199 |
| unsaturation of fatty acids in membrane lipids enhances tolerance of the cyanobacterium synechocystis pcc6803 to low-temperature photoinhibition. | effect of the unsaturation of fatty acids in the glycerolipids of thylakoid membranes on low-temperature photoinhibition of photosynthesis was studied by mutation and transformation of the cyanobacterium synechocystis pcc6803. when grown at 34 degrees c, the wild type contained mono-, di-, and triunsaturated lipids; a mutant, designated fad6, contained mono- and diunsaturated lipids; and a transformant of fad6, with a disrupted gene for desaturation and designated fad6/desa::kmr, contained only ... | 1992 | 1409727 |
| conjugative gene transfer in marine cyanobacteria: synechococcus sp., synechocystis sp. and pseudanabaena sp. | versatility of gene transfer by transconjugation in marine cyanobacteria was demonstrated. in this study, seven different marine cyanobacteria were used as recipient cells. first, transconjugation was carried out using the mobilizable transposon (tn5) carrying plasmid psup1021. transconjugates were observed in all marine cyanobacteria tested. second, the broad-host-range vector pkt0230 (incq) was tested for transconjugation. pkt230 has been successfully transferred in a marine cyanobacterium syn ... | 1992 | 1368911 |
| purification and determination of glutamine synthetase by high-performance immunoaffinity chromatography. | high-performance immunoaffinity chromatography (hpiac) with anti-glutamine synthetase polyclonal antibodies bound to epoxy-activated silica was used to purify and determine this enzyme from the cyanobacterium synechocystis. a single-step hpiac procedure with cell-free extracts yielded electroporetically homogeneous glutamine synthetase. in the determination of glutamine synthetase by hpiac a linear response in the range 10-60 micrograms of enzyme was observed. recoveries of 70% of the loaded enz ... | 1992 | 1347294 |
| heat shock protein synthesis of the cyanobacterium synechocystis pcc 6803: purification of the groel-related chaperonin. | synechocystis pcc 6803 cells could be induced to synthesize four major hsps with apparent molecular sizes of 70, 64, 15 and 14 kda. heat stress at 42.5 degrees c appeared to be the optimum temperature for hsp formation in cells grown at 30 degrees c. the relative rate of synthesis of hsp70 and hsp15 reached a maximum at 30 min after the temperature shift-up whereas the capability of cells to accumulate hsp64 and hsp14 continued through 2 h. the two most abundant hsps, hsp70 and hsp64, were recog ... | 1992 | 1346251 |
| regulation of anabaena sp. strain pcc 7120 glutamine synthetase activity in a synechocystis sp. strain pcc 6803 derivative strain bearing the anabaena glna gene and a mutated host glna gene. | the glna gene from synechocystis sp. strain pcc 6803 was cloned by hybridization with the glna gene from anabaena sp. strain pcc 7120, and a deletion-insertion mutation of the synechocystis gene was generated in vitro. a strain derived from synechocystis sp. strain pcc 6803 which contained integrated into the chromosome, in addition to its own glna gene, the anabaena glna gene was constructed. from that strain, a synechocystis sp. glna mutant could be obtained by transformation with the inactiva ... | 1992 | 1345914 |
| protein-tyrosyl radical interactions in photosystem ii studied by electron spin resonance and electron nuclear double resonance spectroscopy: comparison with ribonucleotide reductase and in vitro tyrosine. | the stable tyrosine radical in photosystem ii, yd*, has been studied by esr and endor spectroscopies to obtain proton hyperfine coupling constants from which the electron spin density distribution can be deduced. simulations of six previously published esr spectra of psii (one at q band; five at x band, of which two were after specific deuteration and two others were of oriented membranes) can be achieved by using a single set of magnetic parameters that includes anisotropic proton hyperfine ten ... | 1992 | 1332777 |
| expression of a higher plant psba gene in synechocystis 6803 yields a functional hybrid photosystem ii reaction center complex. | the psba gene codes for the d1 polypeptide of the photosystem ii reaction center complex and is found in all photosynthetic organisms that carry out oxygenic photosynthesis. here we describe the construction and characterization of a strain of the cyanobacterium synechocystis sp pcc 6803 in which the three endogenous psba genes are replaced by a single psba gene from the chloroplast genome of the higher plant poa annua. the resulting chimeric strain, kwpas, grows photoautotrophically with a doub ... | 1991 | 1840918 |
| involvement of arginine residues in the allosteric activation and inhibition of synechocystis pcc 6803 adpglucose pyrophosphorylase. | adpglucose pyrophosphorylase (ec 2.7.7.27) from the cyanobacterium synechocystis pcc 6803 was desensitized to the effects of allosteric ligands by treatment with the arginine reagent, phenylglyoxal. enzyme modification by phenylglyoxal resulted in inactivation when the enzyme was assayed under 3p-glycerate-activated conditions. there was little loss of the catalytic activity assayed in the absence of activator. pi, 3p-glycerate, and pyridoxal-p were able to protect the enzyme from inactivation, ... | 1992 | 1326983 |
| copper-mediated regulation of cytochrome c553 and plastocyanin in the cyanobacterium synechocystis 6803. | in certain cyanobacteria and algae, cytochrome c553 or plastocyanin can serve to carry electrons from the cytochrome bf complex to photosystem i. the availability of copper in the growth medium regulates which protein is present. to investigate copper induced control of gene expression we isolated these proteins from the cyanobacterium synechocystis 6803. using immunodetection and optical spectroscopy, the steady state levels of cytochrome c553 and plastocyanin were measured in cells grown at di ... | 1992 | 1326543 |
| light-activated heterotrophic growth of the cyanobacterium synechocystis sp. strain pcc 6803: a blue-light-requiring process. | a glucose-tolerant strain of synechocystis sp. strain 6803 will not grow on glucose under complete darkness unless given a daily pulse of white light, typically 5 min of 40 mumol m-2 s-1 (light-pulsed conditions). the light pulse is insufficient for photoautotrophy, as glucose is required and growth yield is dependent on glucose concentration. growth rate is independent of fluence, but growth yield is dependent on fluence, saturating at 40 to 75 mumol m-2 s-1. a synechocystis strain 6803 psba mu ... | 1991 | 1902208 |
| evidence from directed mutagenesis that aspartate 170 of the d1 polypeptide influences the assembly and/or stability of the manganese cluster in the photosynthetic water-splitting complex. | to identify amino acid residues that influence the assembly or stability of the manganese cluster in photosystem ii, we have generated site-directed mutations in the d1 polypeptide of the cyanobacterium, synechocystis sp. pcc 6803. indirect evidence has suggested that the d1 polypeptide provides some of the ligands that are required for metal binding. mutations at position 170 of d1 were selected for characterization, since an aspartate to asparagine mutation (dn170d1) at this position completel ... | 1992 | 1322168 |
| the yf161d1 mutant of synechocystis 6803 exhibits an epr signal from a light-induced photosystem ii radical. | the currently accepted model for the location of the redox-active tyrosines, d and z, in photosystem ii suggests that they are symmetrically located on the d1 and d2 polypeptides, which are believed to form the heterodimer core of the reaction center. z, the electron conduit from the manganese catalytic site to the primary chlorophyll donor, has been identified with tyrosine-161 of d1. the yf161d1 mutant of synechocystis 6803 [debus, r. j., barry, b. a., sithole, i., babcock, g. t., & mcintosh, ... | 1992 | 1313291 |
| oxygen-evolving photosystem ii preparation from wild type and photosystem ii mutants of synechocystis sp. pcc 6803. | we present here a simple and rapid method which allows relatively large quantities of oxygen-evolving photosystem ii- (ps-ii-) enriched particles to be obtained from wild-type and mutants of the cyanobacterium synechocystis 6803. this method is based on that of burnap et al. [burnap, r., koike, h., sotiropoulou, g., sherman, l. a., & inoue, y. (1989) photosynth. res. 22, 123-130] but is modified so that the whole preparation, from cells to ps-ii particles, is achieved in 10 h and involves only o ... | 1992 | 1311205 |
| analysis of the gene encoding the rna subunit of ribonuclease p from cyanobacteria. | the genes encoding the rna subunit of ribonuclease p from the unicellular cyanobacterium synechocystis sp. pcc 6803, and from the heterocyst-forming strains anabaena sp. pcc 7120 and calothrix sp. pcc 7601 were cloned using the homologous gene from anacystis nidulans (synechococcus sp. pcc 6301) as a probe. the genes and the flanking regions were sequenced. the genes from anabaena and calothrix are flanked at their 3'-ends by short tandemly repeated repetitive (strr) sequences. in addition, two ... | 1992 | 1282240 |
| cyanobacterial evolution: results of 16s ribosomal ribonucleic acid sequence analyses. | we report here the sequences of oligonucleotides released by t1-ribonuclease digestion of the 16s ribosomal rna's (rrna's) of unicellular cyanobacteria agmenellum quadruplicatum (strain bg-1) and synechococcus 7502. we compare them with sequences previously obtained for the 16s rna's of six other cyanobacteria and two chloroplasts, and conclude that: (i) synechocystis-like unicells form a discrete cluster which also (and surprisingly) includes agmenelium quadruplicatum, usually considered to be ... | 1979 | 113061 |
| site-directed mutagenesis of the psbc gene of photosystem ii: isolation and functional characterization of cp43-less photosystem ii core complexes. | two mutants of synechocystis pcc 6803 lacking the psbc gene product cp43 were constructed by site-directed mutagenesis. analysis of cells and thylakoid membranes of these mutants indicates that ps ii reaction centers accumulate to a concentration of about 10% of that of wt cells. ps ii core complexes isolated from mutants lacking the cp43 subunit show light-driven electron transfer from the secondary electron donor z to the primary quinone electron acceptor qa with a quantum yield similar to tha ... | 1991 | 1903653 |
| ultrastructural and biochemical characterization of a synechocystis 6803 mutant with inactivated psba genes. | a constructed synechocystis 6803 mutant with a deletion of the three psba genes was subjected to ultrastructural and biochemical characterization. this d1-depleted mutant also lacks the d2 protein and the chlorophyll a-binding protein cp-47. a general ultrastructural comparison between the wild type and the mutant did not reveal any major changes in cell appearance. we found by freeze-fracture analysis that approximately 60% of the endoplasmic face particles found in the wild-type thylakoids wer ... | 1992 | 1586163 |
| truncation of the cooh-terminal domain of the psbe gene product in synechocystis sp. pcc 6803: requirements for photosystem ii assembly and function. | the cooh-terminal domain of the 80-residue cytochrome b559 alpha-subunit (psbe gene product) in synechocystis sp. pcc 6803 was sequentially truncated in order to determine the minimum polypeptide length needed for function and assembly. a stop codon was introduced into the arg-50, arg-59, or tyr-69 codons of the psbe gene, generating mutants truncated by 31, 22, and 12 residues, respectively. removal of 12 residues caused a decrease of 20% in psii function. truncation of 22 or 31 residues caused ... | 1992 | 1567853 |
| construction of insertion mutants of synechocystis sp. pcc 6803: evidence for an essential function of subunit iv of the cytochrome b6/f complex. | the gene encoding subunit iv of the cytochrome b6/f complex (petd) has been isolated from a genomic library of the unicellular cyanobacterium synechocystis sp. pcc 6803. the coding region consists of 480 nucleotides and can code for a polypeptide with a molecular weight of 17.5 kda. the deduced amino acid sequence shows high identity with the corresponding sequences of both the photoautotrophic prokaryote nostoc sp. pcc 7906 as well as of lower and higher photoautotrophic eukaryotes (e.g. chlore ... | 1992 | 1590707 |
| ferredoxin and flavodoxin from the cyanobacterium synechocystis sp pcc 6803. | the unicellular cyanobacterium synechocystis sp pcc 6803 is capable of synthesizing two different photosystem-i electron acceptors, ferredoxin and flavodoxin. under normal growth conditions a [2fe-2s] ferredoxin was recovered and purified to homogeneity. the complete amino-acid sequence of this protein was established. the isoelectric point (pi = 3.48), midpoint redox potential (em = -0.412 v) and stability under denaturing conditions were also determined. this ferredoxin exhibits an unusual ele ... | 1992 | 1633177 |
| nanosecond electron transfer kinetics in photosystem i following substitution of quinones for vitamin k1 as studied by time resolved epr. | room temperature transient epr spectra of photosystem i (ps i) particles from synechocystis 6803 are presented. native ps i samples and preparations depleted in the a1-acceptor site by solvent extraction and then reconstituted with the quinones (q) vitamin k1 (vk1), duroquinone (dq and dqd12) and naphthoquinone (nq) have been studied. sequential electron transfer to p700+a1- (fes) and p700+a1 (fes)- is recovered only with vk1. with dq and nq electron transfer is restored to form the radical pair ... | 1991 | 1647977 |
| partial conservation of the 5' ndhe-psac-ndhd 3' gene arrangement of chloroplasts in the cyanobacterium synechocystis sp. pcc 6803: implications for ndh-d function in cyanobacteria and chloroplasts. | the psac gene, which encodes the 8.9 kda iron-sulfur containing subunit of photosystem i, has been sequenced from synechocystis sp. pcc 6803 and shows greater similarity to reported plant sequences than other cyanobacterial psac sequences. the deduced amino acid sequence of the protein encoded by the synechocystis psac gene is identical to the tobacco psa-c sequence. in plants psac is located in the small single-copy region of the chloroplast genome between two genes (designated ndhe and ndhd) w ... | 1991 | 1907869 |
| a residue substitution in phosphoribulokinase of synechocystis pcc 6803 renders the mutant light-sensitive. | we have isolated a light-sensitive mutant (brls) of the photosynthetic cyanobacterium synechocystis 6803 (s. 6803) that does not survive exposure to bright light: 70% of brls cells die upon exposure to light of greater than 3,000 lux for 2 h. a complementing dna fragment from wild-type cells and the corresponding dna from the brls cells have been cloned and sequenced. an open reading frame is found to encode phosphoribulokinase, a key enzyme in the enzyme system for photosynthetic carbon reducti ... | 1991 | 1660882 |
| acidic cytochrome c6 of unicellular cyanobacteria is an indispensable and kinetically competent electron donor to cytochrome oxidase in plasma and thylakoid membranes. | cytochromes c6 from three cyanobacteria were tested as substrates for membranous cyt. c oxidase(aa3) of anacystis and synechocystis using intact spheroplasts or isolated plasma(cm) and thylakoid(icm) membranes. neither spheroplasts nor cm/icm gave significant o2 uptake rates with nadh without added cyt. c. horse cyt. c (at low ionic strength) or cyt. c6 from anacystis, synechocystis or microcystis (at high ionic strength) supported substantial hcn- & co-sensitive nadh oxidase activity, consisten ... | 1991 | 1665972 |
| molecular cloning of the genes encoding two chaperone proteins of the cyanobacterium synechocystis sp. pcc 6803. | molecular chaperones help other proteins in their correct folding and assembly. we have cloned the genes, cpn60 and dnak, which encode proteins belonging to the chaperonin-60 and the 70-kda heat shock protein families from the transformable cyanobacterium synechocystis sp. pcc 6803. these genes are present in single copies in the genome, and the major transcripts for each gene are monocistronic. comparison of deduced amino acid sequences reveals that cyanobacterial chaperonin-60 is equally homol ... | 1991 | 1670771 |
| regulation of glutamine synthetase activity in the unicellular cyanobacterium synechocystis sp. strain pcc 6803 by the nitrogen source: effect of ammonium. | glutamine synthetase activity from synechocystis sp. strain pcc 6803 is regulated as a function of the nitrogen source available in the medium. addition of 0.25 mm nh4cl to nitrate-grown cells promotes a clear short-term inactivation of glutamine synthetase, whose enzyme activity decreases to 5 to 10% of the initial value in 25 min. the intracellular levels of glutamine, determined under various conditions, taken together with the results obtained with azaserine (an inhibitor of transamidases), ... | 1991 | 1676397 |
| targeted genetic inactivation of the photosystem i reaction center in the cyanobacterium synechocystis sp. pcc 6803. | we describe the first complete segregation of a targeted inactivation of psaa encoding one of the p700-chlorophyll a apoproteins of photosystem (ps) i. a kanamycin resistance gene was used to interrupt the psaa gene in the unicellular cyanobacterium synechocystis sp. pcc 6803. selection of a fully segregated mutant, adk9, was performed under light-activated heterotrophic growth (lahg) conditions; complete darkness except for 5 min of light every 24 h and 5 mm glucose. under these conditions, wil ... | 1991 | 1717264 |
| an hsp70 homolog is encoded on the plastid genome of the red alga, porphyra umbilicalis. | a pcr experiment using porphyra umbilicalis dna as the template and degenerate oligonucleotides representing conserved regions of hsp70 amino acid sequences generated a 1 kb product that hybridized exclusively to the plastid dna of this red alga. dna sequencing of two contiguous ecori plastid dna clones revealed a 620 amino acid open reading frame with 71% identity to the dnak gene of the cyanobacterium, synechocystis 6803. northern hybridization experiments detected a 2.3 kb transcript that is ... | 1991 | 1720741 |
| purification and properties of nadp-isocitrate dehydrogenase from the unicellular cyanobacterium synechocystis sp. pcc 6803. | nadp-dependent isocitrate dehydrogenase activity has been screened in several cyanobacteria grown on different nitrogen sources; in all the strains tested isocitrate dehydrogenase activity levels were similar in cells grown either on ammonium or nitrate. the enzyme from the unicellular cyanobacterium synechocystis sp. pcc 6803 has been purified to electrophoretic homogeneity by a procedure that includes reactive-red-120-agarose affinity chromatography and phenyl-sepharose chromatography as main ... | 1992 | 1730247 |
| aspartate 170 of the photosystem ii reaction center polypeptide d1 is involved in the assembly of the oxygen-evolving manganese cluster. | eleven site-directed mutations were constructed at aspartate 170 of the d1 polypeptide of the photosystem ii (psii) reaction center of the cyanobacterium synechocystis sp. pcc 6803. the light-saturated rates of o2 evolution (vo2) measured in whole cells range from close to that of wild-type for asp170glu to zero for asp170ser and ala. those mutant strains that are best able to evolve o2 are also those that show the lowest km in psii core complexes for the oxidation of mn2+ by oxidized tyr161, th ... | 1992 | 1731951 |
| stearoyl-acyl-carrier-protein desaturase from higher plants is structurally unrelated to the animal and fungal homologs. | stearoyl-acyl-carrier-protein (acp) desaturase (ec 1.14.99.6) was purified to homogeneity from avocado mesocarp, and monospecific polyclonal antibodies directed against the protein were used to isolate full-length cdna clones from ricinus communis (castor) seed and cucumis sativus (cucumber). the nucleotide sequence of the castor clone prcd1 revealed an open reading frame of 1.2 kilobases encoding a 396-amino acid protein of 45 kda. the cucumber clone pcsd1 encoded a homologous 396-amino acid pr ... | 1991 | 2006187 |
| nucleotide sequence and expression of the ndhh gene of the cyanobacterium synechocystis sp. pcc6803. | | 1992 | 1731965 |
| glycinebetaine enhances and stabilizes the evolution of oxygen and the synthesis of atp by cyanobacterial thylakoid membranes. | glycinebetaine (betaine), an osmoregulant in halophilic plants, stabilized the evolution of oxygen and the synthesis of atp by thylakoid membranes from the cyanobacterium synechocystis pcc6803 when it was present during the preparation and incubation of the thylakoid membranes. moreover, betaine enhanced the evolution of oxygen and the synthesis of atp when present during assays. when betaine at 1.0 m was present during the preparation of thylakoid membranes and during the measurement of activit ... | 1991 | 1756870 |
| [investigations of the immunomodulatory effect of cyanobacterial extracts]. | resulting from the knowledge that cyanobacteria (blue-green algae) are able to produce pharmacologically active substances the aqueous extracts from several cyanobacteria species and strains (microcystis aeruginosa, synechocystis aquatilis, oscillatoria redekei, anabaena flos-aque, aphanizomenon flos-aquae, oscillatoria rubescens, oscillatoria tenuis) were tested for their immunomodulating activity. extracts from oscillatoria redekei 051, oscillatoria tenuis 01 and synechocystis aquatilis 428 ca ... | 1991 | 1801597 |
| the atp1 and atp2 operons of the cyanobacterium synechocystis sp. pcc 6803. | the two operons atp1 and atp2, encoding the subunits of the f0f1 atp-synthase, have been cloned and sequenced from the cyanobacterium synechocystis sp. pcc 6803. the organization of the different genes in the operons have been found to resemble that of the cyanobacteria synechococcus sp. pcc 6301 and anabaena sp. pcc 7120. the synechocystis f0f1 atp-synthase has nine subunits. a tenth open reading frame with unknown function was detected at the 5' end of atp1, coding for a putative gene product ... | 1991 | 1832989 |
| epr characterization of an oxygen-evolving photosystem ii preparation from the transformable cyanobacterium synechocystis 6803. | the transformable cyanobacterium synechocystis 6803 has a photosynthetic apparatus that is similar to that of plants. because of the ease with which this organism can be genetically manipulated and isotopically labeled, synechocystis has been used extensively in recent studies of electron transfer in the water-splitting complex, photosystem ii. here, we present the first epr characterization of a highly active oxygen-evolving preparation from this organism. this preparation shows oxygen-evolutio ... | 1991 | 1850295 |
| deletion mutagenesis in synechocystis sp. pcc6803 indicates that the mn-stabilizing protein of photosystem ii is not essential for o2 evolution. | the photosystem ii (psii) reaction center complex coordinates a cluster of mn atoms that are involved in the accumulation of oxidizing equivalents generated by light-induced charge separations within the intrinsic portion of the psii complex. a 33-kda extrinsic protein, termed the mn-stabilizing protein (msp), has been implicated in the stabilization of two of the four mn atoms of the cluster, yet the precise role of this protein in o2 evolution remains to be elucidated. here we describe the con ... | 1991 | 1899025 |
| phycoerythrins of marine unicellular cyanobacteria. i. bilin types and locations and energy transfer pathways in synechococcus spp. phycoerythrins. | marine synechococcus strains wh8103, wh8020, and wh7803 each possess two different phycoerythrins, pe(ii) and pe(i), in a weight ratio of 2-4:1. pe(ii) and pe(i) differ in amino acid sequence and in bilin composition and content. studies with strain wh7803 indicated that both pe(ii) and pe(i) were present in the same phycobilisome rod substructures and that energy absorbed by pe(ii) was transferred to pe(i). strain wh8103 and wh8020 pe(i)s carried five bilin chromophores thioether-linked to cyst ... | 1991 | 1903388 |
| nucleotide sequence of the psbk gene of the cyanobacterium synechocystis 6803. | | 1990 | 2108431 |
| phycoerythrins of marine unicellular cyanobacteria. ii. characterization of phycobiliproteins with unusually high phycourobilin content. | a survey of marine unicellular cyanobacterial strains for phycobiliproteins with high phycourobilin (pub) content led to a detailed investigation of synechocystis sp. wh8501. the phycobiliproteins of this strain were purified and characterized with respect to their bilin composition and attachment sites. amino-terminal sequences were determined for the alpha and beta subunits of the phycocyanin and the major and minor phycoerythrins. the amino acid sequences around the attachment sites of all bi ... | 1991 | 1903389 |
| purification of glutamyl-trna reductase from synechocystis sp. pcc 6803. | delta-aminolevulinic acid is the universal precursor for all tetrapyrroles including hemes, chlorophylls, and bilins. in plants, algae, cyanobacteria, and many other bacteria, delta-aminolevulinic acid is synthesized from glutamate in a reaction sequence that requires three enzymes, atp, nadph, and trna(glu). the three enzymes have been characterized as glutamyl-trna synthetase, glutamyl-trna reductase, and glutamate-1-semialdehyde aminotransferase. all three enzymes have been separated and part ... | 1991 | 1903397 |
| deletion of the psbg1 gene of the cyanobacterium synechocystis sp. pcc6803 leads to the activation of the cryptic psbg2 gene. | the genes psbg1 and psbg2 in the cyanobacterium synechocystis sp. pcc6803 are homologous. the psbg1 gene is located on the chromosome and is part of the ndhc--psbg1--orf157 operon, while psbg2 is located on a plasmid and is not flanked by equivalent ndhc or orf157 genes. mutants in which psbg1 is deleted grow well under autotrophic conditions, while their growth is impeded in mixotrophic medium. these results argue against a functional role for psbg1 in photosynthesis, i.e. photosystem ii, and a ... | 1991 | 1903500 |
| a gene homologous to the subunit-2 gene of nadh dehydrogenase is essential to inorganic carbon transport of synechocystis pcc6803. | a clone that transforms the rka mutant of synechocystis pcc6803 defective in inorganic carbon (ci) transport to the wild-type phenotype was isolated from a cyanobacterial genomic library. the clone contained an 11.8-kilobase-pair dna insert. sequencing of the insert dna in the region of the mutation in rka revealed an open reading frame (designated as ndhb), which showed extensive amino acid sequence homology to the subunit-2 genes of nadh dehydrogenase (ec 1.6.99.3) (ndhb) of chloroplasts and m ... | 1991 | 1903537 |
| site directed mutagenesis of the heme axial ligands of cytochrome b559 affects the stability of the photosystem ii complex. | cytochrome (cyt) b559, an integral membrane protein, is an essential component of the photosystem ii (psii) complex in the thylakoid membranes of oxygenic photosynthetic organisms. cyt b559 has two subunits, alpha and beta, each with one predicted membrane spanning alpha-helical domain. the heme cofactor of this cytochrome is coordinated between two histidine residues. each of the two subunit polypeptides of cyt b559 has one his residue. to investigate the influence of these his residues on the ... | 1991 | 1904816 |
| enhancement of chilling tolerance of a cyanobacterium by genetic manipulation of fatty acid desaturation. | the sensitivity (or tolerance) of plants to chilling determines their choice of natural habitat and also limits the worldwide production of crops. although the molecular mechanism for chilling sensitivity has long been debated, no definitive conclusion has so far been reached about its nature. a probable hypothesis, however, is that chilling injury is initiated by phase transition of lipids of cellular membranes, as demonstrated for cyanobacteria, which serve as a model system for the plant cell ... | 1990 | 2118597 |
| an nad-specific glutamate dehydrogenase from cyanobacteria. identification and properties. | the unicellular cyanobacterium synechocystis sp. pcc 6803 presents a hexameric nad-specific glutamate dehydrogenase with a molecular mass of 295 kda. the enzyme differs from the nadp-glutamate dehydrogenase found in the same strain and is coded by a different gene. nad-glutamate dehydrogenase shows a high coenzyme specificity, catalyzes preferentially glutamate formation and presents km values for ammonium, nadh and 2-oxoglutarate of 4.5 mm, 50 microm and 1.8 mm respectively. an animating role f ... | 1991 | 1906012 |
| primary structure of the psbn-psbh-petc-peta gene cluster of the cyanobacterium synechocystis pcc 6803. | | 1991 | 1907512 |
| cyanobacteria contain a mitochondrial complex i-homologous nadh-dehydrogenase. | thylakoid and cytoplasmic membranes of the cyanobacterium synechocystis sp. pcc 6803 were purified by sucrose gradient centrifugation. both membranes oxidize nadh in a rotenone-sensitive reaction. antibodies prepared against psbg/ndhk and ndhj fusion proteins detect the corresponding polypeptides in both membrane preparations. this demonstrates that a nadh-dehydrogenase, homologous to the mitochondrial nadh-ubiquinone-oxidoreductase (complex i of the respiratory chain) is present in cyanobacteri ... | 1991 | 1907569 |
| purification and characterization of acyl carrier protein from two cyanobacteria species. | the acyl carrier protein (acp), an essential protein cofactor for fatty acid synthesis, has been isolated from two cyanobacteria: the filamentous, heterocystous, anabaena variabilis (atcc 29211) and the unicellular synechocystis 6803 (atcc 27184). both acps have been purified to homogeneity utilizing a three-column procedure. synechocystis 6803 acp was purified 1800-fold with 67% yield, while a. variabilis acp was purified 1040-fold with 50% yield. yields of 13.0 micrograms acp/g synechocystis 6 ... | 1990 | 2123456 |
| nucleotide sequence of the psba3 gene from the cyanobacterium synechocystis pcc 6803. | | 1990 | 2123543 |
| orientation of carotenoids in the outer membrane of synechocystis pcc 6714 (cyanobacteria). | the orientation of outer membrane carotenoids from synechocystis pcc 6714 and synechococcus pcc 6307 was studied by linear dichroism spectrophotometry. uniaxially oriented, tilted outer membrane films revealed a significant linear dichroism after rotating the polarization vector of the incident light beam, indicating a predominant orientation of the carotenoid transition moments perpendicular to the outer membrane plane. values for the reduced dichroism at the absorbance maxima presented a linea ... | 1991 | 1908700 |
| arginine residues in the d2 polypeptide may stabilize bicarbonate binding in photosystem ii of synechocystis sp. pcc. | bicarbonate (hco3-) causes a significant and reversible stimulation of anion-inhibited electron flow in photosystem ii of higher plants and cyanobacteria. to test if selected arginine (arg) residues are involved in the binding of hco3-, we utilized oligonucleotide-directed mutagenesis to construct synechocystis sp. pcc 6803 mutants carrying mutations in arg residues in the d2 protein. measurements of oxygen evolution showed that the d2 mutants r233q (arginine-233----glutamine) and r251s (arginin ... | 1991 | 1909178 |
| separation and partial characterization of enzymes catalyzing delta-aminolevulinic acid formation in synechocystis sp. pcc 6803. | formation of the universal tetrapyrrole precursor, delta-aminolevulinic acid (ala), from glutamate via the five-carbon pathway requires three enzymes: glutamyl-trna synthetase, glutamyl-trna reductase, and glutamate-1-semialdehyde (gsa) aminotransferase. all three enzymes were separated from extracts of the unicellular cyanobacterium synechocystis sp. pcc 6803, and two of them, glutamyl-trna synthetase and gsa aminotransferase, were partially characterized. after an initial high speed centrifuga ... | 1991 | 1910318 |
| sequence conservation among the glucose transporter from the cyanobacterium synechocystis sp. pcc 6803 and mammalian glucose transporters. | synechocystis sp. pcc 6803 is capable of facultative photoheterotrophy with glucose as the sole carbon source. eight mutants that were unable to take up glucose were transformed with plasmids from pooled gene banks of wild-type synechocystis dna prepared in an escherichia coli vector that does not replicate in synechocystis. one mutant (eg216) could be complemented with all gene banks to restore ability for photoheterotrophic growth. one of the gene banks was fractionated into single clones and ... | 1990 | 2129397 |
| photosystem ii characteristics of a constructed synechocystis 6803 mutant lacking synthesis of the d1 polypeptide. | photosystem ii (psii) composition was studied in a mutant of the cyanobacterium synechosystis 6803 in which synthesis of the reaction center polypeptide d1 has been inactivated. the mutant thylakoids had lost also the other reaction center polypeptide d2 and the chlorophyll alpha-binding protein cp47. cytochrome b559 and the chlorophyll alpha-binding protein cp43 accumulated to almost wild-type amounts in mutant thylakoids. also the 33 kda polypeptide involved in water oxidation was present and ... | 1990 | 2129398 |
| the primary structure of the gamma-subunit of the atpase from synechocystis 6803. | the nucleotide sequence of the gene coding for the f0f1-atpase gamma-subunit (atpc) from the transformable cyanobacterium synchocystis 6083 has been determined. the deduced translation product consists of 314 amino acid residues and is highly homologous (72% identical residues) to the sequences of other cyanobacterial gamma-subunits. the synechocystis 6803 sequence is also homologous to the chloroplast gamma-sequence. like in the other cyanobacterial subunits, only the first of the 3 cysteine re ... | 1990 | 2137788 |
| expression of photosynthesis genes in the cyanobacterium synechocystis sp. pcc 6803: psaa-psab and psba transcripts accumulate in dark-grown cells. | we have cloned and sequenced the psaa and psab genes from the unicellular cyanobacterium synechocystis sp. pcc 6803. these genes are arranged in tandem, are co-transcribed, and are highly homologous to the psaa and psab genes previously characterized. rna was isolated from light-grown cells, from cells put in total darkness with and without glucose, and from cells grown under light-activated heterotrophic growth (lahg) conditions. quantitation of hybridization to northern blots revealed only a s ... | 1991 | 1932686 |
| oligonucleotide-directed mutagenesis of psbb, the gene encoding cp47, employing a deletion mutant strain of the cyanobacterium synechocystis sp. pcc 6803. | a mutant strain of the cyanobacterium synechocystis sp. pcc (pasteur culture collection) 6803 has been developed in which psbb, the gene coding for the chlorophyl alpha-binding protein cp47 in photosystem ii (psii), has been deleted. this deletion mutant can be used for the reintroduction of modified psbb into the cyanobacterium. to study the role of a large hydrophilic region in cp47, presumably located on the lumenal side of the thylakoid membrane between the fifth and sixth membrane-spanning ... | 1991 | 1932693 |
| molecular cloning and targeted mutagenesis of the gene psaf encoding subunit iii of photosystem i from the cyanobacterium synechocystis sp. pcc 6803. | photosystem i is one of the two multisubunit pigment-protein complexes in the thylakoid membranes of cyanobacteria. subunit iii of photosystem i complex was isolated from a mutant of the cyanonbacterium synechocystis sp pcc 6803, which lacks subunit ii. the sequence of its nh2-terminal residues was determined and corresponding oligonucleotide probes were used to isolate the gene encoding this subunit. the gene, designated as psaf, codes for a mature protein of 15705 da that is synthesized with a ... | 1991 | 1939076 |
| purification and properties of glutamine synthetases from the cyanobacteria synechocystis sp. strain pcc 6803 and calothrix sp. strain pcc 7601. | glutamine synthetases (gss) from two cyanobacteria, one unicellular (synechocystis sp. strain pcc 6803) and the other filamentous (calothrix sp. strain pcc 7601 [fremyella diplosiphon]), were purified to homogeneity. the biosynthetic activities of both enzymes were strongly inhibited by adp, indicating that the energy charge of the cell might regulate the gs activity. both cyanobacteria exhibited an ammonium-mediated repression of gs synthesis. in addition, the synechocystis sp. showed an inacti ... | 1990 | 1973929 |
| two glutamyl-trna reductase activities in escherichia coli. | delta-aminolevulinic acid (ala) is the first committed precursor for tetrapyrrole biosynthesis. ala formation in escherichia coli occurs in a trna-dependent three-step conversion from glutamate. glu-trna reductase is the key enzyme in this pathway. e. coli k12 contains two glu-trna reductase activities which differ in their molecular weights. here we describe the purification of one of these enzymes. four different chromatographic separations yielded a nearly homogeneous protein. its apparent mo ... | 1991 | 1990004 |
| mutation in phenol-type herbicide resistance maps within the psba gene in synechocystis 6714. | a synechocytis 6714 mutant resistant to the phenol-type herbicide ioxynil was isolated and characterized. sensitivity to dcmu and atrazine was tf measured in whole cells and isolated thylakoids. the mutant presents the same sensitivity to atrazine as the wild type and a slightly increased sensitivity to dcmu. a point mutation has been found at codon 266 in the psbai coding locus (aac to acc) resulting in an amino acid change from asparagine to threonine in the d1 protein. | 1989 | 2495986 |
| the psbc start codon in synechocystis sp. pcc 6803. | the translation start codon for psbc, the gene encoding cp43, a chlorophyll-binding protein of photosystem ii, has been identified for the cyanobacterium synechosystis sp. pcc 6803 using site-directed mutagenesis. an aug codon, about 50 bases upstream from the end of psbd-i had previously been assumed to be the translation start site of psbc. however, the fact that the aug codon is not present in psbc from several other organisms, whereas a gug codon 14 bases upstream from the end of psbd-i is s ... | 1990 | 2105233 |
| mutagenesis by random cloning of an escherichia coli kanamycin resistance gene into the genome of the cyanobacterium synechocystis pcc 6803: selection of mutants defective in photosynthesis. | photosynthetic mutants of the cyanobacterium synechocystis pcc 6803 were produced by a random cartridge mutagenesis method leading to gene inactivation. this procedure relies on random ligation of an escherichia coli kanamycin resistance (kmr) gene to restriction fragments of genomic dna from the host. then recombination occurring during transformation promotes integration of the marker gene into the genome of the recipient cells. several mutants impaired in photosynthesis were obtained by this ... | 1989 | 2499763 |
| characterization of the ndhc-psbg-orf157/159 operon of maize plastid dna and of the cyanobacterium synechocystis sp. pcc6803. | the ndhc and orf159 genes of the maize plastid dna (ptdna) were sequenced and maize orf159 was used to screen a library of genomic dna of the blue-green alga synechocystis sp. pcc 6803. the cyanobacterial gene homologous to orf159 (orf157) was isolated and sequenced. in sequencing the region upstream of orf157, reading frames with homology to the ndhc and psbg genes of maize ptdna were identified. the ndhc and psbg genes overlap in the ptdnas of maize, tobacco and marchantia polymorpha, but are ... | 1989 | 2499764 |
| amino acid sequence of photosystem i subunit iv from the cyanobacterium synechocystis pcc 6803. | we describe here the complete amino acid sequence of photosystem i subunit iv from synechocystis 6803. the molecular mass of 8.0 kda is lower than in higher plants and chlamydomonas, due to the lack of a characteristic, proline-rich, n-terminal sequence. the remaining sequence exhibits a good conservation, with a hydrophilic and strongly basic n-terminal head followed by two hydrophobic domains. there is no possibility of classical membrane-spanning alpha helices. this component is likely to be ... | 1990 | 2105239 |
| a cyanobacterial mutant requiring the expression of ribulose bisphosphate carboxylase from a photosynthetic anaerobe. | ribulose bisphosphate carboxylase is essential for both photoautotrophic and photoheterotrophic growth of the cyanobacterium synechocystis 6803. however, a mutant lacking cyanobacterial carboxylase could be obtained by replacing the natural carboxylase gene with the corresponding gene from rhodospirillum rubrum, a photosynthetic anaerobe. this treatment produced an organism whose growth depended on the activity of the structurally and functionally dissimilar foreign carboxylase. as a further con ... | 1989 | 2503824 |
| genes for phycocyanin subunits in synechocystis sp. strain pcc 6701 and assembly mutant uv16. | the cyanobacterial phycobilisome is a large protein complex located on the photosynthetic membrane. it harvests light energy and transfers it to chlorophyll for use in photosynthesis. phycobilisome assembly mutants in the unicellular cyanobacterium synechocystis sp. strain 6701 have been characterized. one such mutant, uv16, contains a defect in the assembly of the biliprotein phycocyanin. we report the cloning and sequencing of the phycocyanin genes from wild-type synechocystis strain 6701 and ... | 1990 | 2106506 |
| structure and light-regulated expression of phycoerythrin genes in wild-type and phycobilisome assembly mutants of synechocystis sp. strain pcc 6701. | phycoerythrin is a major pigmented component of the phycobilisome, a cyanobacterial light-harvesting complex. it contains bilin-type chromophores that absorb and transfer light energy to chlorophyll protein complexes of the photosynthetic membranes. in many cyanobacteria, phycoerythrin expression is regulated by light wavelength in a response known as chromatic adaptation. green light-grown cells contain higher levels of this biliprotein than do cells grown in red light. the phycoerythrin gene s ... | 1990 | 2106507 |
| nucleotide sequence of the psbh gene of the cyanobacterium synechocystis 6803. | | 1990 | 2106663 |
| nucleotide sequence of the second psbg gene in synechocystis 6803. possible implications for psbg function as a nad(p)h dehydrogenase subunit gene. | nucleotide sequencing of the second synechocystis 6803 psbg gene, psbg2 shows the predicted polypeptide to be 219 amino acids long. it is less similar to chloroplast psbg genes than is the synechocystis psbg1 copy. alignment with seven other psbg protein sequences, including that from the paramecium mitochondrial genome reveals a central highly conserved region common to each. this is discussed as evidence supporting the proposal that the psbg polypeptide is a nad(p)h dehydrogenase (complex i) s ... | 1990 | 2108054 |