Required for the cleavage of the signal sequence of TasA and TapA, which are involved in biofilm formation. Cleavage of hydrophobic, N-terminal signal or leader sequences from secreted and periplasmic proteins. Part of the tapA-sipW-tasA operon (PubMed:10464223). Expression is directly repressed by the DNA-binding protein master regulator of biofilm formation SinR and activated by the extracellular matrix regulatory protein RemA (PubMed:16430695, PubMed:23646920). Expressed constitutively at a low level (PubMed:9694797). Also positively regulated by the sporulation transcription factors sigma H and Spo0A and repressed by the transition phase regulatory protein AbrB, probably indirectly (PubMed:10464223). Mutation impairs colony surface architecture. B.subtilis contains five chromosomal type I signal peptidases: SipS, SipT, SipU, SipV and SipW. They have different, but overlapping, substrate specificities and have different transcription patterns. Belongs to the peptidase S26B family.