ID   LEXA_LIGS1              Reviewed;         206 AA.
AC   Q1WUI6;
DT   18-MAR-2008, integrated into UniProtKB/Swiss-Prot.
DT   02-MAY-2006, sequence version 1.
DT   03-AUG-2022, entry version 96.
DE   RecName: Full=LexA repressor {ECO:0000255|HAMAP-Rule:MF_00015};
DE            EC=3.4.21.88 {ECO:0000255|HAMAP-Rule:MF_00015};
GN   Name=lexA {ECO:0000255|HAMAP-Rule:MF_00015}; OrderedLocusNames=LSL_0540;
OS   Ligilactobacillus salivarius (strain UCC118) (Lactobacillus salivarius).
OC   Bacteria; Firmicutes; Bacilli; Lactobacillales; Lactobacillaceae;
OC   Ligilactobacillus.
OX   NCBI_TaxID=362948;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=UCC118;
RX   PubMed=16617113; DOI=10.1073/pnas.0511060103;
RA   Claesson M.J., Li Y., Leahy S., Canchaya C., van Pijkeren J.P.,
RA   Cerdeno-Tarraga A.M., Parkhill J., Flynn S., O'Sullivan G.C., Collins J.K.,
RA   Higgins D., Shanahan F., Fitzgerald G.F., van Sinderen D., O'Toole P.W.;
RT   "Multireplicon genome architecture of Lactobacillus salivarius.";
RL   Proc. Natl. Acad. Sci. U.S.A. 103:6718-6723(2006).
CC   -!- FUNCTION: Represses a number of genes involved in the response to DNA
CC       damage (SOS response), including recA and lexA. In the presence of
CC       single-stranded DNA, RecA interacts with LexA causing an autocatalytic
CC       cleavage which disrupts the DNA-binding part of LexA, leading to
CC       derepression of the SOS regulon and eventually DNA repair.
CC       {ECO:0000255|HAMAP-Rule:MF_00015}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=Hydrolysis of Ala-|-Gly bond in repressor LexA.; EC=3.4.21.88;
CC         Evidence={ECO:0000255|HAMAP-Rule:MF_00015};
CC   -!- SUBUNIT: Homodimer. {ECO:0000255|HAMAP-Rule:MF_00015}.
CC   -!- SIMILARITY: Belongs to the peptidase S24 family. {ECO:0000255|HAMAP-
CC       Rule:MF_00015}.
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DR   EMBL; CP000233; ABD99349.1; -; Genomic_DNA.
DR   RefSeq; WP_003699857.1; NC_007929.1.
DR   RefSeq; YP_535432.1; NC_007929.1.
DR   AlphaFoldDB; Q1WUI6; -.
DR   SMR; Q1WUI6; -.
DR   STRING; 362948.LSL_0540; -.
DR   MEROPS; S24.001; -.
DR   EnsemblBacteria; ABD99349; ABD99349; LSL_0540.
DR   GeneID; 57059028; -.
DR   KEGG; lsl:LSL_0540; -.
DR   PATRIC; fig|362948.14.peg.618; -.
DR   HOGENOM; CLU_066192_45_1_9; -.
DR   OMA; HVWLLPH; -.
DR   Proteomes; UP000006559; Chromosome.
DR   GO; GO:0003677; F:DNA binding; IEA:UniProtKB-UniRule.
DR   GO; GO:0004252; F:serine-type endopeptidase activity; IEA:UniProtKB-UniRule.
DR   GO; GO:0006281; P:DNA repair; IEA:UniProtKB-UniRule.
DR   GO; GO:0006260; P:DNA replication; IEA:UniProtKB-UniRule.
DR   GO; GO:0045892; P:negative regulation of transcription, DNA-templated; IEA:UniProtKB-UniRule.
DR   GO; GO:0006508; P:proteolysis; IEA:InterPro.
DR   GO; GO:0009432; P:SOS response; IEA:UniProtKB-UniRule.
DR   CDD; cd00090; HTH_ARSR; 1.
DR   CDD; cd06529; S24_LexA-like; 1.
DR   Gene3D; 1.10.10.10; -; 1.
DR   HAMAP; MF_00015; LexA; 1.
DR   InterPro; IPR011991; ArsR-like_HTH.
DR   InterPro; IPR006200; LexA.
DR   InterPro; IPR039418; LexA-like.
DR   InterPro; IPR036286; LexA/Signal_pep-like_sf.
DR   InterPro; IPR006199; LexA_DNA-bd_dom.
DR   InterPro; IPR006197; Peptidase_S24_LexA.
DR   InterPro; IPR015927; Peptidase_S24_S26A/B/C.
DR   InterPro; IPR036388; WH-like_DNA-bd_sf.
DR   InterPro; IPR036390; WH_DNA-bd_sf.
DR   Pfam; PF01726; LexA_DNA_bind; 1.
DR   Pfam; PF00717; Peptidase_S24; 1.
DR   PRINTS; PR00726; LEXASERPTASE.
DR   SUPFAM; SSF46785; SSF46785; 1.
DR   SUPFAM; SSF51306; SSF51306; 1.
DR   TIGRFAMs; TIGR00498; lexA; 1.
PE   3: Inferred from homology;
KW   Autocatalytic cleavage; DNA damage; DNA repair; DNA replication;
KW   DNA-binding; Hydrolase; Reference proteome; Repressor; SOS response;
KW   Transcription; Transcription regulation.
FT   CHAIN           1..206
FT                   /note="LexA repressor"
FT                   /id="PRO_0000322740"
FT   DNA_BIND        28..48
FT                   /note="H-T-H motif"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   ACT_SITE        128
FT                   /note="For autocatalytic cleavage activity"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   ACT_SITE        166
FT                   /note="For autocatalytic cleavage activity"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   SITE            93..94
FT                   /note="Cleavage; by autolysis"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
SQ   SEQUENCE   206 AA;  22998 MW;  382669FFEF4D33DB CRC64;
     MTKSEKRQHD ILRYIFSHVS DSGYPPTVRE ICNAVGLSST STVHGHLSKL ESKGLIKRDP
     TKPRAIEITL AGLEMLDELP NKTQIPIVGT VTAGEPILAV EENRDYFPLP PYFESADDLF
     MLSIRGESMI NAGILDGDQV IVRKQSSANN GEIVIAMTEE NEATCKRFFK EDGYYRLQPE
     NDTMDPIILE NVTILGKVVG LYRDLI