Peptidase S24, LexA-like (IPR006197)

Short name: Peptidase_S24_LexA

Overlapping homologous superfamilies

Family relationships


This signature defines serine peptidases belong to MEROPS peptidase family S24 (LexA family, clan SF). They include:

  • LexA, the repressor of genes in the cellular SOS response to DNA damage
  • MucA and the related UmuD proteins, which are lesion-bypass DNA polymerases, induced in response to mitogenic DNA damage
  • RumA a plasmid encoded homologue of UmuD [PMID: 8709953]
  • RuvA, which is a component of the RuvABC resolvasome that catalyses the resolution of Holliday junctions that arise during genetic recombination and DNA repair [PMID: 12423347]

The LexA, UmuD and MucD proteins interact with RecA, which activates self cleavage either derepressing transcription in the case of LexA [PMID: 10692372] or activating the lesion-bypass polymerase in the case of UmuD and MucA. UmuD'2, is the homodimeric component of DNA pol V, which is produced from UmuD by RecA-facilitated self-cleavage. The first 24 N-terminal residues of UmuD are removed; UmuD'2 is a DNA lesion bypass polymerase [PMID: 10692372, PMID: 11483531]. MucA [PMID: 9925794, PMID: 11016960], like UmuD, is a plasmid encoded a DNA polymerase (pol RI) which is converted into the active lesion-bypass polymerase by a self-cleavage reaction involving RecA [PMID: 11114935].

This group of proteins also contains proteins classified as non-peptidase homologues as they either have been found experimentally to be without peptidase activity, or lack amino acid residues that are believed to be essential for catalytic activity.

GO terms

Biological Process

GO:0006355 regulation of transcription, DNA-templated

Molecular Function

GO:0003677 DNA binding

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.