Purity > 90% as determined by SDS-PAGE. MW: 38.4kDa. Full Length: 1-202aa. N-terminal 6xHis-SUMO-tagged. Escherichia coli (strain K12). Represses a number of genes involved in the response to DNA damage (SOS response), including recA and lexA. Binds to the 16 bp palindromic sequence 5'-CTGTATATATATACAG-3'. In the presence of single-stranded DNA, RecA interacts with LexA causing an autocatalytic cleavage which disrupts the DNA-binding part of LexA, leading to derepression of the SOS regulon and eventually DNA repair. Implicated in hydroxy radical-mediated cell death induced by hydroxyurea treatment.The SOS response controls an apoptotic-like death (ALD) induced (in the absence of the mazE-mazF toxin-antitoxin module) in response to DNA damaging agents that is mediated by RecA and LexA