Transcription regulator LexA (IPR006200)

Short name: LexA

Overlapping homologous superfamilies

Family relationships


LexA acts as a homodimer to repress a number of genes involved in the response to DNA damage (SOS response), including itself and RecA. RecA, in the presence of single-stranded DNA, acts as a co-protease to activate a latent autolytic protease activity (EC: of LexA, where the active site Ser is part of LexA. The autolytic cleavage site is an Ala-Gly bond in LexA (at position 84-85 in E. coli LexA; this sequence is replaced by Gly-Gly in Synechocystis). The cleavage leads to derepression of the SOS regulon and eventually to DNA repair. LexA in Bacillus subtilis is called DinR. LexA is much less broadly distributed than RecA [PMID: 8798618, PMID: 9555905].

GO terms

Biological Process

GO:0009432 SOS response
GO:0045892 negative regulation of transcription, DNA-templated

Molecular Function

GO:0004252 serine-type endopeptidase activity

Cellular Component

No terms assigned in this category.

Contributing signatures

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