ID   LEXA_CLOPS              Reviewed;         203 AA.
AC   Q0STQ8;
DT   15-JAN-2008, integrated into UniProtKB/Swiss-Prot.
DT   05-SEP-2006, sequence version 1.
DT   03-AUG-2022, entry version 95.
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=CPR_1177;
OS   Clostridium perfringens (strain SM101 / Type A).
OC   Bacteria; Firmicutes; Clostridia; Eubacteriales; Clostridiaceae;
OC   Clostridium.
OX   NCBI_TaxID=289380;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=SM101 / Type A;
RX   PubMed=16825665; DOI=10.1101/gr.5238106;
RA   Myers G.S.A., Rasko D.A., Cheung J.K., Ravel J., Seshadri R., DeBoy R.T.,
RA   Ren Q., Varga J., Awad M.M., Brinkac L.M., Daugherty S.C., Haft D.H.,
RA   Dodson R.J., Madupu R., Nelson W.C., Rosovitz M.J., Sullivan S.A.,
RA   Khouri H., Dimitrov G.I., Watkins K.L., Mulligan S., Benton J., Radune D.,
RA   Fisher D.J., Atkins H.S., Hiscox T., Jost B.H., Billington S.J.,
RA   Songer J.G., McClane B.A., Titball R.W., Rood J.I., Melville S.B.,
RA   Paulsen I.T.;
RT   "Skewed genomic variability in strains of the toxigenic bacterial pathogen,
RT   Clostridium perfringens.";
RL   Genome Res. 16:1031-1040(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; CP000312; ABG87657.1; -; Genomic_DNA.
DR   AlphaFoldDB; Q0STQ8; -.
DR   SMR; Q0STQ8; -.
DR   MEROPS; S24.001; -.
DR   EnsemblBacteria; ABG87657; ABG87657; CPR_1177.
DR   KEGG; cpr:CPR_1177; -.
DR   OMA; HVWLLPH; -.
DR   Proteomes; UP000001824; 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; Repressor; SOS response; Transcription;
KW   Transcription regulation.
FT   CHAIN           1..203
FT                   /note="LexA repressor"
FT                   /id="PRO_1000001279"
FT   DNA_BIND        30..50
FT                   /note="H-T-H motif"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   ACT_SITE        127
FT                   /note="For autocatalytic cleavage activity"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   ACT_SITE        164
FT                   /note="For autocatalytic cleavage activity"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   SITE            91..92
FT                   /note="Cleavage; by autolysis"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
SQ   SEQUENCE   203 AA;  22936 MW;  727789D8CC73B477 CRC64;
     MIIKENSDKQ TQIYNFLIEF TKSKGYPPSV REICQAVSLK STSTVHGHLK RLEKKGLIYR
     DPTKPRALEI VELSNEEKEL IDIPIVGKVT AGMPILATEN IEDMFQIPIN YVKHNNDLFI
     LKVTGDSMIE AGILDGDLAI IEQKNIATNG DIVVALIENE ATIKRFFKEN GFIRLQPENK
     NYEPIIVEDC SILGKLVGIY RAY