ID   LEXA_CLONN              Reviewed;         204 AA.
AC   A0Q0N2;
DT   18-MAR-2008, integrated into UniProtKB/Swiss-Prot.
DT   09-JAN-2007, sequence version 1.
DT   03-AUG-2022, entry version 94.
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=NT01CX_2111;
OS   Clostridium novyi (strain NT).
OC   Bacteria; Firmicutes; Clostridia; Eubacteriales; Clostridiaceae;
OC   Clostridium.
OX   NCBI_TaxID=386415;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=NT;
RX   PubMed=17115055; DOI=10.1038/nbt1256;
RA   Bettegowda C., Huang X., Lin J., Cheong I., Kohli M., Szabo S.A., Zhang X.,
RA   Diaz L.A. Jr., Velculescu V.E., Parmigiani G., Kinzler K.W., Vogelstein B.,
RA   Zhou S.;
RT   "The genome and transcriptomes of the anti-tumor agent Clostridium novyi-
RT   NT.";
RL   Nat. Biotechnol. 24:1573-1580(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; CP000382; ABK61190.1; -; Genomic_DNA.
DR   RefSeq; WP_011722184.1; NC_008593.1.
DR   AlphaFoldDB; A0Q0N2; -.
DR   SMR; A0Q0N2; -.
DR   STRING; 386415.NT01CX_2111; -.
DR   MEROPS; S24.001; -.
DR   PRIDE; A0Q0N2; -.
DR   EnsemblBacteria; ABK61190; ABK61190; NT01CX_2111.
DR   KEGG; cno:NT01CX_2111; -.
DR   eggNOG; COG1974; Bacteria.
DR   HOGENOM; CLU_066192_45_1_9; -.
DR   OMA; HVWLLPH; -.
DR   OrthoDB; 1933795at2; -.
DR   Proteomes; UP000008220; 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..204
FT                   /note="LexA repressor"
FT                   /id="PRO_0000322725"
FT   DNA_BIND        29..49
FT                   /note="H-T-H motif"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   ACT_SITE        126
FT                   /note="For autocatalytic cleavage activity"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   ACT_SITE        163
FT                   /note="For autocatalytic cleavage activity"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   SITE            90..91
FT                   /note="Cleavage; by autolysis"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
SQ   SEQUENCE   204 AA;  22816 MW;  47C6C9E113E4CE94 CRC64;
     MSRSSEDKQI EIYEFIKEQI IEKGYPPSVR EICKGVGLSS TSSVHGHLSK LEKKGLIRRD
     STKPRTIEIL KEPIVPKEMV NIPILGKVTA GTPILAVENI EDTFPISLNF IPSNKDLFML
     KISGESMIDA GILDGDLAII EKTNTAKNGE IVVALIDNEV TLKRFFKEDK HIRLQPENKN
     MDPIILEDDS VSIVGKLAGI FRRY