Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effect of copper on the levels of plastocyanin (PC) and cytochrome c553 (cyt-c)-specific transcripts from Anabaena sp. PCC 7937 was investigated. The addition of copper resulted in a marked increase in PC mRNA levels, and a decrease in cyt c mRNA levels. Thus the functional exchange between PC and cyt c seems to be regulated at the mRNA level. The copper-dependent increase in PC and decrease in cyt c mRNA levels was abolished when chloramphenicol was added to the cells. This suggests that de novo synthesis of at least one trans-acting element is required to regulate PC and cyt c mRNA levels. Both PC and cyt c mRNA stability was found to be unaltered under varying Cu2+ regimes. This leads to the conclusion that expression of both genes is regulated at the level of initiation of transcription.
Mol Microbiol 1992 Jun
PMID:Transcriptional regulation of the plastocyanin and cytochrome c553 genes from the cyanobacterium Anabaena species PCC 7937. 132 Jul 27

Previous studies have indicated that ADP-glucose pyrophosphorylase (ADPGlc PPase) from the cyanobacterium Anabaena sp. strain PCC 7120 is more similar to higher-plant than to enteric bacterial enzymes in antigenicity and allosteric properties. In this paper, we report the isolation of the Anabaena ADPGlc PPase gene and its expression in Escherichia coli. The gene we isolated from a genomic library utilizes GTG as the start codon and codes for a protein of 48,347 Da which is in agreement with the molecular mass determined by SDS-PAGE for the Anabaena enzyme. The deduced amino acid sequence is 63, 54, and 33% identical to the rice endosperm small subunit, maize endosperm large subunit, and the E. coli sequences, respectively. Southern analysis indicated that there is only one copy of this gene in the Anabaena genome. The cloned gene encodes an active ADPGlc PPase when expressed in an E. coli mutant strain AC70R1-504 which lacks endogenous activity of the enzyme. The recombinant enzyme is activated and inhibited primarily by 3-phosphoglycerate and Pi, respectively, as is the native Anabaena ADPGlc PPase. Immunological and other biochemical studies further confirmed the recombinant enzyme to be the Anabaena enzyme.
Plant Mol Biol 1992 Oct
PMID:Molecular cloning and expression of the gene encoding ADP-glucose pyrophosphorylase from the cyanobacterium Anabaena sp. strain PCC 7120. 132 5

A nuclease that could be recovered from the supernatant of cultures, as well as from cell-free extracts, of the cyanobacterium Anabaena sp. PCC 7120 was identified as a 29 kDa polypeptide by its ability to degrade DNA after electrophoresis in DNA-containing SDS-polyacrylamide gels. Some clones of a gene library of strain PCC 7120 established in Escherichia coli were found to produce the 29 kDa nuclease. The nucA gene encoding this nuclease was subcloned and sequenced. The deduced polypeptide, NucA, had a molecular weight of 29,650, presented a presumptive signal peptide in its N-terminal region and showed homology to the products of the nuc gene from Serratia marcescens and the NUC1 gene from Saccharomyces cerevisiae. The NucA protein from Anabaena itself, or from the cloned nucA gene expressed in E. coli, catalysed the degradation of both RNA and DNA, had the potential to act as an endonuclease, and functioned best in the presence of Mn2+ or Mg2+. An Anabaena nucA insertional mutant was generated which failed to produce the 29 kDa nuclease.
Mol Microbiol 1992 Oct
PMID:Identification, genetic analysis and characterization of a sugar-non-specific nuclease from the cyanobacterium Anabaena sp. PCC 7120. 134 21

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 recognized on western blots by antibodies raised against authentic DnaK and GroEL from Escherichia coli. To furnish sufficient evidence for the assumption that HSP64 is a GroEL-related chaperonin, this protein was purified to homogeneity. There was a 76% sequence identity between the amino acid sequence of HSP64 and the corresponding protein in Synechococcus PCC 7942. Moreover, the purified HSP64 cross-reacted to anti-E. coli GroEL antibody. To our knowledge, this is the first report about the purification and partial protein sequencing of a cyanobacterial chaperonin.
Plant Mol Biol 1992 Jan
PMID:Heat shock protein synthesis of the cyanobacterium Synechocystis PCC 6803: purification of the GroEL-related chaperonin. 134 51

The genome of the cyanobacterium Synechococcus sp. strain PCC 7942 contains two psbD genes encoding the D2 protein of the photosystem II reaction center: psbDI, which is cotranscribed as a discistronic message with psbC (the gene encoding CP43, a chlorophyll-a binding protein), and psbDII, which is monocistronic. Northern blot analysis of psbD transcripts showed that the two genes responded differently when wild-type cells were shifted from moderate to high light intensity. Whereas psbDII transcripts increased 500% relative to unshifted control cells, psbDI-psbC transcripts remained unchanged. The beta-galactosidase activities expressed from translational fusions between the psbD genes and the Escherichia coli lacZ reporter gene displayed responses similar to those seen in the RNA. D2 protein levels in thylakoid membranes from wild-type cells increased to 250% of those of the unshifted control cells 12 h after a shift to high light intensities. In contrast, in a mutant strain (AMC016) that carries an inactive psbDII gene, D2 levels decreased by 50% under identical conditions. These results suggested that induction of psbDII gene expression by light can serve as a supplementary system for maintaining a functional photosystem II reaction center at high light intensity. This hypothesis was corroborated by mixed-culture experiments, in which AMC016 cells competed poorly with wild-type cells at high light intensity. These data suggest for the first time that differential expression of members of a cyanobacterial gene family serves to maintain a functional PSII reaction center under diverse environmental conditions.
Mol Gen Genet 1992 Mar
PMID:Light-regulated expression of the psbD gene family in Synechococcus sp. strain PCC 7942: evidence for the role of duplicated psbD genes in cyanobacteria. 137 52

Arginine auxotrophs of the dinitrogen-fixing cyanobacterium Anabaena species strain PCC 7120 were isolated after ultraviolet light mutagenesis and penicillin enrichment. Two of these auxotrophs were complemented by a cosmid gene library of the wild-type strain established in Escherichia coli that was transferred en masse to the mutants by conjugation. The gene complementing one of those mutants was found to complement an E. coli argC mutant. Sequencing analysis of the gene showed that it encodes a 322-residue polypeptide that is homologous to the ArgC protein of E. coli, Bacillus subtilis and Streptomyces clavuligerus and to the C-terminal moiety of the Saccharomyces cerevisiae ARG5,6 gene product, N-acetylglutamate semialdehyde dehydrogenase. A cysteine residue present in a highly conserved domain in the five proteins is probably located in the active site of the enzyme. Conserved among the ArgC proteins, sequences resembling the primary structure of nucleotide-binding domains are also found. Downstream of the Anabaena argC gene seven nearly perfect repeats of a heptanucleotide (consensus sequence:5'-CTAATGA-3') are found.
Mol Microbiol 1992 Aug
PMID:Isolation of arginine auxotrophs, cloning by mutant complementation, and sequence analysis of the argC gene from the cyanobacterium Anabaena species PCC 7120. 140 50

The genes encoding the photosynthetic cytochrome b6 (petB) and subunit 4 (petD) have been cloned and sequenced from the unicellular, photoheterotrophic, transformable cyanobacterium Synechococcus sp. PCC 7002, formerly designated Agmenellum quadruplicatum. The gene arrangement was found to be similar to that reported in the cyanobacterium Nostoc PCC 7906. The DNA and derived protein sequences were compared to chloroplast and the other cyanobacterial sequences. By pulsed-field electrophoresis, the petBD operon and the petCA operon, encoding the Rieske iron-sulfur protein and cytochrome f, were found to be located on separate, unlinked, Not I-digested DNA fragments. The petBD operon was found on the third largest Not I fragment (NC-325) while the petCA operon was found on the second largest Not I fragment (NB-370). These results suggest the two operons are not in proximity. The 1.35 kb transcript was shown to be light-regulated. Transcripts from cells grown under constant illumination showed a decrease in petB transcript levels to undetectable levels within 2 h after the cells were placed in the dark. Upon reillumination, transcript levels rose to three-fold over that seen initially under constant illumination.
Plant Mol Biol 1992 Nov
PMID:Cloning and sequencing of the petBD operon from the cyanobacterium Synechococcus sp. PCC 7002. 142 Nov 51

The structural gene encoding a thioredoxin-dependent 5'-phosphoadenylyl sulphate (PAPS) reductase (EC 1.8.4.-) from cyanobacterium Synechococcus PCC 7942 ('Anacystis nidulans') was detected by heterologous hybridization with the cysH gene from Escherichia coli K12. The cyanobacterial gene (further called par gene) comprised 696 nt which are 57.8% homologous to the enterobacterial gene. The putative open reading frame encoded a polypeptide consisting of 232 amino acid residues (deduced molecular weight 26,635) which showed significant homologies to the polypeptide from E. coli (50.8%) and to the polypeptide from Saccharomyces cerevisiae (30.3%). A single cysteine located at the C-terminus of the polypeptide of E. coli (Cys239) was conserved in Synechococcus. Conservation of this cysteinyl residue seems indispensable for catalysis. Complementation of a cysH-deficient mutant of E. coli by the cyanobacterial gene indicated that the cloned DNA is the structural gene of the PAPS reductase.
Plant Mol Biol 1992 Dec
PMID:Primary structure of the Synechococcus PCC 7942 PAPS reductase gene. 146 52

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 to a deletion in the 5'-region (creating a 5' truncation) and a mutation associated with an insertion of the Rhodospirillum rubrum rbc gene, yielding a high-CO2-requiring mutant ('cyanorubrum'). The 3' and the 5' truncated rbcL genes were linked to chloramphenicol and kanamycin resistance markers, respectively. Decreasing the kanamycin selective pressure concomitantly with exposure of the double resistance mutant to air, resulted in air-growing colonies. Analysis of their genomes, Rubisco proteins, and their ultrastructure revealed: 1) Reconstitution of a full-length cyanobacterial rbcL gene at the rbc locus; 2) simultaneous synthesis of the cyanobacterial (L8S8) and R. rubrum (L2) enzymes in meroploids containing both mutated and reconstituted rbcL genes; 3) reappearance of carboxysomes. Our results indicate extensive recombinatorial interactions between the homologous sequences at both loci leading to reconstitution of the cyanobacterial rbcL gene.
Mol Gen Genet 1992 Nov
PMID:Restoration of the wild-type locus in an RuBP carboxylase/oxygenase mutant of Synechocystis PCC 6803 via targeted gene recombination. 146 99

The complete nucleotide sequence is presented for pUH24, the small plasmid of Synechococcus sp. PCC 7942. pUH24 consists of 7835bp and has a G + C content of 59%. The distribution of translation start and stop codons in the sequence allows 36 open reading frames that potentially encode polypeptides of 50 or more amino acids. We postulate that eight of these open reading frames are actual coding sequences. A region has been identified, by experiment, that contains two functions, designated pmaA and pmaB, involved in the segregational stability of the plasmid. The minimal region of pUH24 fully capable of supporting autonomous replication consists of a 3.6kb DNA fragment, which is almost entirely occupied by two overlapping genes most likely coding for essential replication proteins (repA and repB).
Mol Microbiol 1992 Mar
PMID:Identification of replication and stability functions in the complete nucleotide sequence of plasmid pUH24 from the cyanobacterium Synechococcus sp. PCC 7942. 155 63


1 2 3 4 5 6 7 8 9 10 Next >>