Interaction of Bacillus subtilis extracytoplasmic function (ECF) sigma factors with the N-terminal regions of their potential anti-sigma factors.
Extracytoplasmic function (ECF) sigma factors constitute a diverse family of proteins, within the class of the sigma 70 subunit of RNA polymerase. Most members of the family studied to date are known to regulate gene expression in response to stress conditions. The Bacillus subtilis genome encodes at least 17 distinct sigma factors, seven of which are members of the ECF subfamily. Among these, five sigma factors, namely SigV, SigW, SigX, SigY and SigM, are encoded by the first genes of the cognate sigma operons. Disruption or repressed expression of the downstream gene(s) resulted in transcriptional activation of the cognate sigma operon. Moreover, in vivo protein-protein interaction analyses by yeast two-hybrid experiments indicated that these immediate downstream gene products bind the cognate ECF sigma factor, suggesting that they function as anti-sigma factors by capturing sigma factor on the inner surface of the cytoplasmic membrane. Interaction with other sigma factors was not observed. The results presented here also show that these anti-sigma factors interact with ECF sigma factors through their N-terminal region, implying that the N-terminal domain resides inside the cytoplasmic membrane.
Yoshimura
Mika
M
Department of Bioscience, Tokyo University of Agriculture, Sakuragaoka, Setagaya-ku, Tokyo 156-8502, Japan.
Asai
Kei
K
Department of Biochemistry and Molecular Biology, Faculty of Sciences, Saitama University, Saitama 338-7507, Japan.
Sadaie
Yoshito
Y
Department of Biochemistry and Molecular Biology, Faculty of Sciences, Saitama University, Saitama 338-7507, Japan.
Yoshikawa
Hirofumi
H
Department of Bioscience, Tokyo University of Agriculture, Sakuragaoka, Setagaya-ku, Tokyo 156-8502, Japan.
D001412:Bacillus subtilis / Q000235:genetics / Q000502:physiology*; D001426:Bacterial Proteins / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D001483:Base Sequence; D001665:Binding Sites; D004269:DNA, Bacterial / Q000235:genetics; D012321:DNA-Directed RNA Polymerases / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D015964:Gene Expression Regulation, Bacterial; D015971:Gene Expression Regulation, Enzymologic; D005798:Genes, Bacterial; D007763:Lac Operon; D008958:Models, Molecular; D008969:Molecular Sequence Data; D005810:Multigene Family; D009876:Operon; D017434:Protein Structure, Tertiary; D012808:Sigma Factor / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D020798:Two-Hybrid System Techniques
D001426:Bacterial Proteins; D004269:DNA, Bacterial; C413458:SigW protein, Bacillus subtilis; C093265:SigX protein, Bacillus subtilis; D012808:Sigma Factor; C081775:RNA polymerase sigma 70; D012321:DNA-Directed RNA Polymerases