A comparison of gene organization in the zwf region of the genomes of the cyanobacteria Synechococcus sp. PCC 7942 and Anabaena sp. PCC 7120 |
| |
Authors: | Julie Newman Haydar Karakaya David J Scanlan Nicholas H Mann |
| |
Institution: | Department of Biological Sciences, University of Warwick, Coventry CV4 7AL, UK |
| |
Abstract: | 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 . |
| |
Keywords: | Glucose-6-phosphate dehydrogenase zwf Fructose-1 6-bisphosphatase Synechococcus Anabaena |
|
|