title: Mutation in ntrC gene leading to the derepression of nitrogenase synthesis in Rhodobacter sphaeroides.
abstract: 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.
authors.affiliation: Department of Genetics, Moscow State University, Russia. vzin@string.stringer.ru
authors.forename: V
authors.initials: V
authors.lastname: Zinchenko
authors.forename: M
authors.initials: M
authors.lastname: Babykin
authors.forename: V
authors.initials: V
authors.lastname: Glaser
authors.forename: S
authors.initials: S
authors.lastname: Mekhedov
authors.forename: S
authors.initials: S
authors.lastname: Shestakov
mesh_terms: 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
chemical_list: 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