ISSN:
1573-5079
Keywords:
Anabaena
;
ferredoxin
;
flavodoxin
;
FPLC determination of ferredoxin and flavodoxin
;
Iron deficiency
;
Nitrogen fixation
;
Photosynthesis
;
strain differences in gene expression
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Iron-dependent formation of ferredoxin and flavodoxin was determined in Anabaena ATCC 29413 and ATCC 29211 by a FPLC procedure. In the first species ferredoxin is replaced by flavodoxin at low iron levels in the vegetative cells only. In the heterocysts from Anabaena ATCC 29151, however, flavodoxin is constitutively formed regardless of the iron supply. Replacement of ferredoxin by flavodoxin had no effect on photosynthetic electron transport, whereas nitrogen fixation was decreased under low iron conditions. As ferredoxin and flavodoxin exhibited the same Km values as electron donors to nitrogenase, an iron-limited synthesis of active nitrogenase was assumed as the reason for inhibited nitrogen fixation. Anabaena ATCC 29211 generally lacks the potential to synthesize flavodoxin. Under iron-starvation conditions, ferredoxin synthesis is limited, with a negative effect on photosynthetic oxygen evolution.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00047083
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