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.
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Department of Biochemistry, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, Piscataway 08854-5635.
Inouye
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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