EC - SpoIVB peptidase

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IntEnz Enzyme Nomenclature


Accepted name:
SpoIVB peptidase
Other names:
sporulation factor IV B protease
stage IV sporulation protein B
Systematic name:



This enzyme plays a central role in a regulatory checkpoint (the σK checkpoint), which coordinates gene expression during the later stages of spore formation in Bacillus subtilis [1,3]. The enzyme activates proteolytic processing of a sporulation-specific sigma factor, pro-σK, to its mature and active form, σK, by self-cleavage [1,3]. The enzyme is also subject to secondary proteolysis, which presumably inactivates SpoIVB [3]. The enzyme is also essential for the formation of heat-resistant spores. Belongs in peptidase family S55.

Links to other databases

Enzymes and pathways: NC-IUBMB , BRENDA , ExplorEnz , ENZYME@ExPASy , KEGG , MetaCyc , MEROPS , UniPathway
Protein domains and families: PROSITE:PDOC51494
Structural data: CSA , EC2PDB


  1. Wakeley, P.R., Dorazi, R., Hoa, N.T., Bowyer, J.R. and Cutting, S.M.
    Proteolysis of SpolVB is a critical determinant in signalling of Pro-σK processing in Bacillus subtilis.
    Mol. Microbiol. 36 : 1336-1348 (2000). [PMID: 10931284]
  2. Hoa, N.T., Brannigan, J.A. and Cutting, S.M.
    The PDZ domain of the SpoIVB serine peptidase facilitates multiple functions.
    J. Bacteriol. 183 : 4364-4373 (2001). [PMID: 11418578]
  3. Hoa, N.T., Brannigan, J.A. and Cutting, S.M.
    The Bacillus subtilis signaling protein SpoIVB defines a new family of serine peptidases.
    J. Bacteriol. 184 : 191-199 (2002). [PMID: 11741860]
  4. Dong, T.C. and Cutting, S.M.
    SpoIVB-mediated cleavage of SpoIVFA could provide the intercellular signal to activate processing of Pro-σK in Bacillus subtilis.
    Mol. Microbiol. 49 : 1425-1434 (2003). [PMID: 12940997]

[EC created 2006]