A new putative sigma factor of Myxococcus xanthus.
A third putative sigma factor gene, sigC, has been isolated from Myxococcus xanthus by using the sigA gene (formerly rpoD of M. xanthus) as a probe. The nucleotide sequence of sigC has been determined, and an open reading frame of 295 residues (M(r) = 33,430) has been identified. The deduced amino acid sequence of sigC exhibits the features which are characteristic of other bacterial sigma factors. The characterization of a sigC-lacZ strain has demonstrated that sigC expression is induced immediately after cells enter into the developmental cycle and is dramatically reduced at the onset of sporulation. A deletion mutant of sigC grows normally in vegetative culture and is able to develop normally. However, in contrast to the wild-type cells, the sigC deletion mutant cells became capable of forming fruiting bodies and myxospores on semirich agar plates. This suggests that sigC may play a role in expression of genes involved in negatively regulating the initiation of fruiting body formation.
Department of Biochemistry, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, Piscataway 08854-5635.
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D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics*; D001483:Base Sequence; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins; D012321:DNA-Directed RNA Polymerases / Q000096:biosynthesis / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics; D008969:Molecular Sequence Data; D009024:Morphogenesis / Q000235:genetics; D016941:Myxococcus xanthus / Q000166:cytology / Q000235:genetics*; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D017422:Sequence Analysis, DNA; D017384:Sequence Deletion; D017386:Sequence Homology, Amino Acid; D012808:Sigma Factor / Q000096:biosynthesis / Q000235:genetics*; D001616:beta-Galactosidase / Q000096:biosynthesis / Q000235:genetics
D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D011993:Recombinant Fusion Proteins; D012808:Sigma Factor; C081467:sigC protein, Bacteria; C081775:RNA polymerase sigma 70; D012321:DNA-Directed RNA Polymerases; D001616:beta-Galactosidase