ID   LEXA_LEPCP              Reviewed;         231 AA.
AC   B1Y250;
DT   24-MAR-2009, integrated into UniProtKB/Swiss-Prot.
DT   20-MAY-2008, sequence version 1.
DT   03-AUG-2022, entry version 83.
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=Lcho_2082;
OS   Leptothrix cholodnii (strain ATCC 51168 / LMG 8142 / SP-6) (Leptothrix
OS   discophora (strain SP-6)).
OC   Bacteria; Proteobacteria; Betaproteobacteria; Burkholderiales; Leptothrix.
OX   NCBI_TaxID=395495;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC 51168 / LMG 8142 / SP-6;
RG   US DOE Joint Genome Institute;
RA   Copeland A., Lucas S., Lapidus A., Glavina del Rio T., Dalin E., Tice H.,
RA   Bruce D., Goodwin L., Pitluck S., Chertkov O., Brettin T., Detter J.C.,
RA   Han C., Kuske C.R., Schmutz J., Larimer F., Land M., Hauser L.,
RA   Kyrpides N., Lykidis A., Emerson D., Richardson P.;
RT   "Complete sequence of Leptothrix cholodnii SP-6.";
RL   Submitted (MAR-2008) to the EMBL/GenBank/DDBJ databases.
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; CP001013; ACB34349.1; -; Genomic_DNA.
DR   RefSeq; WP_012347109.1; NC_010524.1.
DR   AlphaFoldDB; B1Y250; -.
DR   SMR; B1Y250; -.
DR   STRING; 395495.Lcho_2082; -.
DR   MEROPS; S24.001; -.
DR   PRIDE; B1Y250; -.
DR   EnsemblBacteria; ACB34349; ACB34349; Lcho_2082.
DR   KEGG; lch:Lcho_2082; -.
DR   eggNOG; COG1974; Bacteria.
DR   HOGENOM; CLU_066192_45_3_4; -.
DR   OMA; HVWLLPH; -.
DR   OrthoDB; 1933795at2; -.
DR   Proteomes; UP000001693; 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..231
FT                   /note="LexA repressor"
FT                   /id="PRO_1000089576"
FT   DNA_BIND        31..51
FT                   /note="H-T-H motif"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   ACT_SITE        148
FT                   /note="For autocatalytic cleavage activity"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   ACT_SITE        185
FT                   /note="For autocatalytic cleavage activity"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   SITE            113..114
FT                   /note="Cleavage; by autolysis"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
SQ   SEQUENCE   231 AA;  25315 MW;  DD48D98903A9DAAD CRC64;
     MQDSPKLTAR QQQILDLIQS TIERTGAPPT RAEIATEFGF RSANAAEEHL QALARKGVIE
     LLGGTSRGIR LKSDTLRSIN ESRLRGIGQQ FSLPLSNMPP AQLTLPLVGR VAAGSPILAQ
     QHIDQSYTFE AHMFSRKPDF LLKVRGMSMR DAGILDGDLI AVQRASEAKN GQIVVARLGD
     EVTVKRWRRS KSGIDLIPEN PDFDIIHVPA DSPDFALEGL AVGLIRNTML M