ID   LEXA_PROMH              Reviewed;         203 AA.
AC   B4EYR3;
DT   24-MAR-2009, integrated into UniProtKB/Swiss-Prot.
DT   23-SEP-2008, sequence version 1.
DT   03-AUG-2022, entry version 92.
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=PMI2749;
OS   Proteus mirabilis (strain HI4320).
OC   Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales;
OC   Morganellaceae; Proteus.
OX   NCBI_TaxID=529507;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=HI4320;
RX   PubMed=18375554; DOI=10.1128/jb.01981-07;
RA   Pearson M.M., Sebaihia M., Churcher C., Quail M.A., Seshasayee A.S.,
RA   Luscombe N.M., Abdellah Z., Arrosmith C., Atkin B., Chillingworth T.,
RA   Hauser H., Jagels K., Moule S., Mungall K., Norbertczak H.,
RA   Rabbinowitsch E., Walker D., Whithead S., Thomson N.R., Rather P.N.,
RA   Parkhill J., Mobley H.L.T.;
RT   "Complete genome sequence of uropathogenic Proteus mirabilis, a master of
RT   both adherence and motility.";
RL   J. Bacteriol. 190:4027-4037(2008).
CC   -!- FUNCTION: Represses a number of genes involved in the response to DNA
CC       damage (SOS response), including recA and lexA. Binds to the 16 bp
CC       palindromic sequence 5'-CTGTATATATATACAG-3'. In the presence of single-
CC       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; AM942759; CAR45417.1; -; Genomic_DNA.
DR   RefSeq; WP_004245906.1; NC_010554.1.
DR   AlphaFoldDB; B4EYR3; -.
DR   SMR; B4EYR3; -.
DR   STRING; 529507.PMI2749; -.
DR   MEROPS; S24.001; -.
DR   EnsemblBacteria; CAR45417; CAR45417; PMI2749.
DR   GeneID; 6802602; -.
DR   KEGG; pmr:PMI2749; -.
DR   eggNOG; COG1974; Bacteria.
DR   HOGENOM; CLU_066192_45_3_6; -.
DR   OMA; HVWLLPH; -.
DR   Proteomes; UP000008319; 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; cd06529; S24_LexA-like; 1.
DR   Gene3D; 1.10.10.10; -; 1.
DR   HAMAP; MF_00015; LexA; 1.
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..203
FT                   /note="LexA repressor"
FT                   /id="PRO_1000089584"
FT   DNA_BIND        28..48
FT                   /note="H-T-H motif"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   ACT_SITE        120
FT                   /note="For autocatalytic cleavage activity"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   ACT_SITE        157
FT                   /note="For autocatalytic cleavage activity"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   SITE            85..86
FT                   /note="Cleavage; by autolysis"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
SQ   SEQUENCE   203 AA;  22444 MW;  C34E8C9FDF87805A CRC64;
     MKALTARQQQ VYDLVRDHIS QTGMPPTRAE IASQLGFRSP NAAEEHLKAL ARKGVIEIVS
     GASRGIRLLL EEEPEGLPLI GRVAAGEPLL AQEHIESHYQ VDPMLFKPSA DFLLRVNGMS
     MKDIGIMDGD LLAVHKTQDV HNGQVIVARI EDEVTVKRFK KVGSKIELHA ENPEFSPIIV
     DLREQSFTVE GLAVGVIRNG EWL