Glucose-6-phosphate dehydrogenase (G6PDH) is a key enzyme involved in fixed carbon dissimilation in photosynthetic microorganisms ; in heterocystous cyanobacteria it may also be implicated in the supply of reductant to nitrogenase. In crude cell-free extracts of the N,-fixing cyanobacterium Anabaena variabilis G6PDH activity was reversibly deactivated by the thiol agent dithiothreitol in the pr...
