Open AccessElectron transport to nitrogenase in Rhodospirillum rubrum : the role of NAD(P)H as electron donor and the effect of fluoroacetate on nitrogenase activity
Author(s) -
Brostedt Erica,
Lindblad Anders,
Jansson Janet,
Nordlund Stefan
Publication year - 1997
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1997.tb10379.x
Subject(s) - fluoroacetate , nitrogenase , rhodospirillum rubrum , citric acid cycle , nad+ kinase , chemistry , rhodospirillaceae , biochemistry , electron transport chain , nitrogen fixation , enzyme , nitrogen , organic chemistry
The role of the reactions of the TCA cycle in the generation of reductant for nitrogenase in Rhodospirillum rubrum has been investigated. Addition of fluoroacetate inhibited nitrogenase activity almost completely when pyruvate or endogenous sources were used as electron donors, whereas the inhibition was incomplete when malate, succinate or fumarate were used. Addition of NAD(P)H to cells supported nitrogenase activity, both with and without prior addition of fluoroacetate. We suggest that the role of the TCA cycle in nitrogen fixation in R. rubrum is to generate reduced pyridine nucleotides which are oxidized by the components of the electron transport pathway to nitrogenase.