title: A comparison of gene organization in the zwf region of the genomes of the cyanobacteria Synechococcus sp. PCC 7942 and Anabaena sp. PCC 7120.
abstract: The region of the genome encoding the glucose-6-phosphate dehydrogenase gene zwf was analysed in a unicellular cyanobacterium, Synechococcus sp. PCC 7942, and a filamentous, heterocystous cyanobacterium, Anabaena sp. PCC 7120. Comparison of cyanobacterial zwf sequences revealed the presence of two absolutely conserved cysteine residues which may be implicated in the light/dark control of enzyme activity. The presence in both strains of a gene fbp, encoding fructose-1,6-bisphosphatase, upstream from zwf strongly suggests that the oxidative pentose phosphate pathway in these organisms may function to completely oxidize glucose 6-phosphate to CO2. The amino acid sequence of fructose-1,6-bisphosphatase does not support the idea of its light activation by a thiol/disulfide exchange mechanism. In the case of Anabaena sp. PCC 7120, the tal gene, encoding transaldolase, lies between zwf and fbp.
authors.affiliation: Department of Biological Sciences, University of Warwick, Coventry, UK.
authors.forename: J
authors.initials: J
authors.lastname: Newman
authors.forename: H
authors.initials: H
authors.lastname: Karakaya
authors.forename: D J
authors.initials: DJ
authors.lastname: Scanlan
authors.forename: N H
authors.initials: NH
authors.lastname: Mann
mesh_terms: D000595:Amino Acid Sequence; D017033:Anabaena / Q000201:enzymology / Q000235:genetics*; D000458:Cyanobacteria / Q000201:enzymology / Q000235:genetics*; D006597:Fructose-Bisphosphatase / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics; D005798:Genes, Bacterial / Q000235:genetics; D005954:Glucosephosphate Dehydrogenase / Q000235:genetics; D008969:Molecular Sequence Data; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
chemical_list: D005954:Glucosephosphate Dehydrogenase; D006597:Fructose-Bisphosphatase