Mutation in ntrC gene leading to the derepression of nitrogenase synthesis in Rhodobacter sphaeroides.
The Rhodobacter sphaeroides mutants Drn12 and Drn21 derepressed for nitrogenase synthesis in the presence of ammonia and impaired in utilization of certain nitrogen sources have been analyzed. Both mutants show a low level of expression of the glnBA operon. The DNA fragment restoring the wild-type phenotype to these mutants contains the 3'-portion of ntrB gene and the entire ntrC gene. Sequence analysis showed that Drn12 bears a missense mutation in the ntrC gene. The mutation results in the replacement of a glycine residue by aspartate within the N-terminal domain of the NtrC protein. Pleiotropic phenotypes of Drn12 and Drn21 appear to be associated with an alteration in the regulation of glnBA expression.
Zinchenko
V
V
Department of Genetics, Moscow State University, Russia. vzin@string.stringer.ru
Babykin
M
M
Glaser
V
V
Mekhedov
S
S
Shestakov
S
S
D001426:Bacterial Proteins / Q000235:genetics; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins / Q000235:genetics*; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology; D005798:Genes, Bacterial / Q000502:physiology; D005974:Glutamate-Ammonia Ligase / Q000235:genetics / Q000378:metabolism; D005973:Glutamine / Q000378:metabolism; D008744:Methylamines / Q000378:metabolism; D009154:Mutation / Q000502:physiology; D009584:Nitrogen / Q000378:metabolism; D009591:Nitrogenase / Q000096:biosynthesis*; D016366:Open Reading Frames / Q000235:genetics; D051922:PII Nitrogen Regulatory Proteins; D010957:Plasmids; D000644:Quaternary Ammonium Compounds / Q000378:metabolism; D012242:Rhodobacter sphaeroides / Q000201:enzymology* / Q000235:genetics*; D017422:Sequence Analysis, DNA; D015534:Trans-Activators; D014157:Transcription Factors
D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D008744:Methylamines; D051922:PII Nitrogen Regulatory Proteins; D000644:Quaternary Ammonium Compounds; D015534:Trans-Activators; D014157:Transcription Factors; D005973:Glutamine; C027451:methylamine; D009591:Nitrogenase; C081173:glutamine synthetase I; D005974:Glutamate-Ammonia Ligase; D009584:Nitrogen