A distinct ferredoxin for nitrogen fixation isolated from heterocysts of the cyanobacterium Anabaena variabilis
1985; Wiley; Volume: 184; Issue: 2 Linguagem: Inglês
10.1016/0014-5793(85)80627-x
ISSN1873-3468
AutoresBernhard Schrautemeier, Herbert Böhme,
Tópico(s)Metal-Catalyzed Oxygenation Mechanisms
ResumoFerredoxin from heterocysts of Anabaena variabilis has been isolated and its biological activity compared to ferredoxin obtained from vegetative cells of the same organism. Both ferredoxins catalyze equally effective NADP + photoreduction by heterocyst thylakoids. When photoreduced, both ferredoxins transfer electrons to nitrogenase from A. variabilis , with heterocyst ferredoxin being twice as active as vegetative cell ferredoxin. In the dark, however, only heterocyst ferredoxin is able to link reducing power, generated by soluble systems, such as H 2 /hydrogenase (from Clostridium pasteurianum ) and NADPH/ferredoxin:NADP + oxidoreductase (from A. variabilis ), to the cyanobacterial nitrogenase. Using heterocyst homogenates with glucose 6‐phosphate as electron donor, only ferredoxin from heterocysts is able to stimulate nitrogenase activity further.
Referência(s)