ID   LEXA_CLOBH              Reviewed;         201 AA.
AC   A5I2R7; A7G478;
DT   18-MAR-2008, integrated into UniProtKB/Swiss-Prot.
DT   26-JUN-2007, sequence version 1.
DT   03-AUG-2022, entry version 90.
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};
GN   OrderedLocusNames=CBO1795, CLC_1737;
OS   Clostridium botulinum (strain Hall / ATCC 3502 / NCTC 13319 / Type A).
OC   Bacteria; Firmicutes; Clostridia; Eubacteriales; Clostridiaceae;
OC   Clostridium.
OX   NCBI_TaxID=441771;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=Hall / ATCC 3502 / NCTC 13319 / Type A;
RX   PubMed=17519437; DOI=10.1101/gr.6282807;
RA   Sebaihia M., Peck M.W., Minton N.P., Thomson N.R., Holden M.T.G.,
RA   Mitchell W.J., Carter A.T., Bentley S.D., Mason D.R., Crossman L.,
RA   Paul C.J., Ivens A., Wells-Bennik M.H.J., Davis I.J., Cerdeno-Tarraga A.M.,
RA   Churcher C., Quail M.A., Chillingworth T., Feltwell T., Fraser A.,
RA   Goodhead I., Hance Z., Jagels K., Larke N., Maddison M., Moule S.,
RA   Mungall K., Norbertczak H., Rabbinowitsch E., Sanders M., Simmonds M.,
RA   White B., Whithead S., Parkhill J.;
RT   "Genome sequence of a proteolytic (Group I) Clostridium botulinum strain
RT   Hall A and comparative analysis of the clostridial genomes.";
RL   Genome Res. 17:1082-1092(2007).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=Hall / ATCC 3502 / NCTC 13319 / Type A;
RX   PubMed=18060065; DOI=10.1371/journal.pone.0001271;
RA   Smith T.J., Hill K.K., Foley B.T., Detter J.C., Munk A.C., Bruce D.C.,
RA   Doggett N.A., Smith L.A., Marks J.D., Xie G., Brettin T.S.;
RT   "Analysis of the neurotoxin complex genes in Clostridium botulinum A1-A4
RT   and B1 strains: BoNT/A3, /Ba4 and /B1 clusters are located within
RT   plasmids.";
RL   PLoS ONE 2:E1271-E1271(2007).
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; CP000727; ABS37659.1; -; Genomic_DNA.
DR   EMBL; AM412317; CAL83334.1; -; Genomic_DNA.
DR   RefSeq; WP_011986377.1; NC_009698.1.
DR   RefSeq; YP_001254295.1; NC_009495.1.
DR   RefSeq; YP_001387593.1; NC_009698.1.
DR   AlphaFoldDB; A5I2R7; -.
DR   SMR; A5I2R7; -.
DR   MEROPS; S24.001; -.
DR   GeneID; 5186050; -.
DR   KEGG; cbh:CLC_1737; -.
DR   KEGG; cbo:CBO1795; -.
DR   PATRIC; fig|413999.7.peg.1765; -.
DR   HOGENOM; CLU_066192_45_1_9; -.
DR   OMA; HVWLLPH; -.
DR   PRO; PR:A5I2R7; -.
DR   Proteomes; UP000001986; 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..201
FT                   /note="LexA repressor"
FT                   /id="PRO_0000322722"
FT   DNA_BIND        29..49
FT                   /note="H-T-H motif"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   ACT_SITE        125
FT                   /note="For autocatalytic cleavage activity"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   ACT_SITE        162
FT                   /note="For autocatalytic cleavage activity"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   SITE            89..90
FT                   /note="Cleavage; by autolysis"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
SQ   SEQUENCE   201 AA;  22578 MW;  9329CD35E326D833 CRC64;
     MNKSRIDKQN EVYNFIKLQI KEKGYPPSVR EICKAVGLSS TSSVHFHLKR LEKEGLIKRD
     SSKTRAIEIV DPTSKKEVIN VPIVGTITAG NPILAIENIE DVFPLPIDYV KNTKDLFMLK
     VSGESMIEAG ILNGDLAIIE KTDSANNGDI VVALIDNEAT LKRFFKESSY IRLQPENKSM
     KPIILENCKV LGRLVGIYRK Y