Summary: Multiple molecular forms of glucose-6-phosphate dehydrogenase (G6PDH) were detected by activity staining in non-denaturing polyacrylamide gels of cell-free extracts from a range of cyanobacteria including sp. PCC 7120, sp. PCC 7942, PCC 73110, sp. PCC 6803, sp. MAC PCC 8009 and the marine strain sp. WH7803. In most of the species tested, the profile of G6PDH activities was modulated by the growth of the cells in the presence of exogenous 10 mM glucose. Using an antiserum raised against a fragment of G6PDH from sp. PCC 7120, it was shown that the different molecular forms of G6PDH all contained an antigenically related subunit, suggesting that the different forms arose from different quaternary structures involving the same monomer. An insertion mutant of sp. PCC 7942 was constructed in which the gene, adjacent to (encoding G6PDH), was disrupted. Although no reduction in the amount of G6PDH monomers (Zwf) was observed in the mutant, activity staining of native gels indicated that most of this protein is not assembled into one of the active oligomeric forms. The oligomerization of G6PDH in extracts of the mutant was stimulated by a factor present in crude extracts of the wild-type, suggesting that the product of the gene is involved in the oligomerization and activation of G6PDH.


Article metrics loading...

Loading full text...

Full text loading...


Most cited this month

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error