ID   LEXA_POLSJ              Reviewed;         234 AA.
AC   Q129C4;
DT   18-MAR-2008, integrated into UniProtKB/Swiss-Prot.
DT   22-AUG-2006, sequence version 1.
DT   03-AUG-2022, entry version 99.
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=Bpro_2954;
OS   Polaromonas sp. (strain JS666 / ATCC BAA-500).
OC   Bacteria; Proteobacteria; Betaproteobacteria; Burkholderiales;
OC   Comamonadaceae; Polaromonas; unclassified Polaromonas.
OX   NCBI_TaxID=296591;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=JS666 / ATCC BAA-500;
RX   PubMed=18723656; DOI=10.1128/aem.00197-08;
RA   Mattes T.E., Alexander A.K., Richardson P.M., Munk A.C., Han C.S.,
RA   Stothard P., Coleman N.V.;
RT   "The genome of Polaromonas sp. strain JS666: insights into the evolution of
RT   a hydrocarbon- and xenobiotic-degrading bacterium, and features of
RT   relevance to biotechnology.";
RL   Appl. Environ. Microbiol. 74:6405-6416(2008).
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; CP000316; ABE44868.1; -; Genomic_DNA.
DR   RefSeq; WP_011483866.1; NC_007948.1.
DR   AlphaFoldDB; Q129C4; -.
DR   SMR; Q129C4; -.
DR   STRING; 296591.Bpro_2954; -.
DR   MEROPS; S24.001; -.
DR   EnsemblBacteria; ABE44868; ABE44868; Bpro_2954.
DR   KEGG; pol:Bpro_2954; -.
DR   eggNOG; COG1974; Bacteria.
DR   HOGENOM; CLU_066192_45_3_4; -.
DR   OMA; HVWLLPH; -.
DR   OrthoDB; 1933795at2; -.
DR   Proteomes; UP000001983; 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..234
FT                   /note="LexA repressor"
FT                   /id="PRO_0000322753"
FT   DNA_BIND        41..61
FT                   /note="H-T-H motif"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   ACT_SITE        152
FT                   /note="For autocatalytic cleavage activity"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   ACT_SITE        189
FT                   /note="For autocatalytic cleavage activity"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   SITE            117..118
FT                   /note="Cleavage; by autolysis"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
SQ   SEQUENCE   234 AA;  25883 MW;  982F5BFA335F020C CRC64;
     MSILNDFSHL SSEGPKLTAR QQQILELIQS AITRTGAPPT RAEIANELGF KSANAAEEHL
     QALARKGVIE LVSGTSRGIR LRSDTLRSIH ESRVKQFSLP LQSLAQLALP LVGRVAAGSP
     ILAQEHIEQT YYFESSLFQR QPDYLLKVRG MSMRDAGIID GDLLAVKQAK EARNGQIVVA
     RIGDEVTVKR FRRTKHLIEL LPENPDFKTI VVEPGEPFEL EGLAVGLIRN TMLI