Photosynthetic electron transport, ATP synthesis and nitrogenase activity in isolated heterocysts of Anabaena cylindrica.
Isolated heterocysts of the N2-fixing blue-green alga Anabaena cylindrica contain the Photosystem I components P-700, bound and soluble ferredoxins and ferredoxin-NADP reductase. They also show Photosystem I activity being able to photoreduce both methylviologen and NADP when ascorbate + dichlorophenol-indophenol acts as reductant. They photophosphorylate (64 munol ATP produced/mg chlorophyll a/h) and carry out oxidative phosphorylation (8.7 munol ATP produced/mg chlorophyll a/h). Ninety per cent of the total cell-free extract nitrogenase activity is located in the heterocyst fraction of aerobic cultures.
D000255:Adenosine Triphosphate / Q000378:metabolism*; D000458:Cyanobacteria / Q000378:metabolism*; D003580:Cytochromes / Q000378:metabolism; D004579:Electron Transport; D005288:Ferredoxins / Q000378:metabolism; D009247:NADH, NADPH Oxidoreductases / Q000378:metabolism; D009591:Nitrogenase / Q000378:metabolism*; D010785:Photophosphorylation; D010788:Photosynthesis; D013347:Subcellular Fractions / Q000378:metabolism
D003580:Cytochromes; D005288:Ferredoxins; D000255:Adenosine Triphosphate; D009591:Nitrogenase; D009247:NADH, NADPH Oxidoreductases