Probable anti-sigma M factor YhdK (IPR020496)

Short name: Anti-sigma_M_YhdK

Overlapping homologous superfamilies


Family relationships



Extracytoplasmic function (ECF) sigma factors are a diverse family of proteins within the class of the sigma 70 subunit of RNA polymerase. Most members 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.

The ECF sigma factor sigma M, encoded by the sigM(yhdM) gene, has been found to be essential for growth and survival in nutrient broth (NB) containing 1.4 M NaCl. The activity of sigma M is negatively regulated by the proteins encoded by the yhdL and yhdK genes [PMID: 10216858]. YhdK binds the cognate ECF sigma factor, suggesting that it functions as an anti-sigma factor by capturing the sigma factor on the inner surface of the cytoplasmic membrane. Furthermore, the anti-sigma factors interact with ECF sigma factors through their N-terminal region, implying that the N-terminal domain resides inside the cytoplasmic membrane [PMID: 14993308].

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
  • PD065873 (Probable_anti-sigma-M_fac_YhdK)