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ENZYME entry: EC

Accepted Name
SpoIVB peptidase
Alternative Name(s)
sporulation factor IV B protease
stage IV sporulation protein B
Reaction catalysed
Self-cleaves 52-Val-|-Asn-53, 62-Ala-|-Phe-63 and 74-Val-|-Thr-75 at the N-terminus of SpoIVB
  • This enzyme plays a central role in a regulatory checkpoint (the sigma(K) checkpoint), which coordinates gene expression during the later stages of spore formation in Bacillus subtilis.
  • The enzyme activates proteolytic processing of a sporulation-specific sigma factor, pro-sigma(K), to its mature and active form, sigma(K), by self-cleavage.
  • The enzyme is also subject to secondary proteolysis, which presumably inactivates SpoIVB.
  • The enzyme is also essential for the formation of heat-resistant spores.
  • Belongs to peptidase family S55.
PRIAM enzyme-specific profiles3.4.21.116
KEGG Ligand Database for Enzyme Nomenclature3.4.21.116
IUBMB Enzyme Nomenclature3.4.21.116
MEDLINEFind literature relating to
Rhea expert-curated reactions3.4.21.116
P17896, SP4B_BACSU

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