Regulation ofNitrogenase inthePhotosynthetic Bacterium Rhodopseudomonas capsulata asStudied byTwo- Dimensional GelElectrophoresis

By using two-dimensional electrophoresis, fiveputative soluble nifgene products wereidentified, andtheregulation ofnif geneexpression inRhodopseudomonas capsulata wasinvestigated. Expression ofnif wasrepressed byammoniaandatmospheric concentrations ofoxygen. Deprivation ofmolybdenum caused aninteresting pattern ofpartial repression ofnif geneexpression that was notrelieved bytungsten. Theseresults arediscussed inrelation tothebetter understood system ofnifregulation inKlebsiella pneumoniae. Theidentification ofnifgenesandnifgene products andregulation oftheexpression ofthe nif genes arewell advanced forKlebsiella pneumoniae. Theuseoftwo-dimensional polyacrylamidegelelectrophoresis fortheanalysis of Nifstrains together withtheavailability ofa large numberofgenetically well-characterized