The SOS response is a global response to DNA damage in which the cell cycle is arrested and DNA repair and mutagenesis are induced. The system involves the RecA protein.The RecA protein, stimulated by single-stranded DNA, is involved in the inactivation of the LexA thereby inducing the response. It is an error-prone repair system that is attributed to mutagenesis.
SOS genes include lexA, recA, uvrA, uvrB, and uvrD.

Source : https://en.wikipedia.org/wiki/SOS_res...