ID   LEXA_AZOSB              Reviewed;         202 AA.
AC   A1K776;
DT   15-JAN-2008, integrated into UniProtKB/Swiss-Prot.
DT   06-FEB-2007, sequence version 1.
DT   03-AUG-2022, entry version 91.
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=azo2064;
OS   Azoarcus sp. (strain BH72).
OC   Bacteria; Proteobacteria; Betaproteobacteria; Rhodocyclales; Zoogloeaceae;
OC   Azoarcus.
OX   NCBI_TaxID=418699;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=BH72;
RX   PubMed=17057704; DOI=10.1038/nbt1243;
RA   Krause A., Ramakumar A., Bartels D., Battistoni F., Bekel T., Boch J.,
RA   Boehm M., Friedrich F., Hurek T., Krause L., Linke B., McHardy A.C.,
RA   Sarkar A., Schneiker S., Syed A.A., Thauer R., Vorhoelter F.-J.,
RA   Weidner S., Puehler A., Reinhold-Hurek B., Kaiser O., Goesmann A.;
RT   "Complete genome of the mutualistic, N2-fixing grass endophyte Azoarcus sp.
RT   strain BH72.";
RL   Nat. Biotechnol. 24:1385-1391(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; AM406670; CAL94681.1; -; Genomic_DNA.
DR   RefSeq; WP_011765795.1; NC_008702.1.
DR   AlphaFoldDB; A1K776; -.
DR   SMR; A1K776; -.
DR   STRING; 62928.azo2064; -.
DR   MEROPS; S24.001; -.
DR   EnsemblBacteria; CAL94681; CAL94681; azo2064.
DR   KEGG; aoa:dqs_2190; -.
DR   KEGG; azo:azo2064; -.
DR   eggNOG; COG1974; Bacteria.
DR   HOGENOM; CLU_066192_45_3_4; -.
DR   OMA; HVWLLPH; -.
DR   OrthoDB; 1933795at2; -.
DR   Proteomes; UP000002588; 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..202
FT                   /note="LexA repressor"
FT                   /id="PRO_1000001257"
FT   DNA_BIND        32..52
FT                   /note="H-T-H motif"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   ACT_SITE        121
FT                   /note="For autocatalytic cleavage activity"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   ACT_SITE        158
FT                   /note="For autocatalytic cleavage activity"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   SITE            86..87
FT                   /note="Cleavage; by autolysis"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
SQ   SEQUENCE   202 AA;  22023 MW;  B13D7A43761CA120 CRC64;
     MNARNEQLTS RQQEILDFIR QTVESEGRPP TRAEVCSAFG FKSPNAAETH LRALAAKGAI
     LLEEGRARGI RLAEALGLPL VGRVAAGNPI LAAEHVEARI QFDPALFSPR ADYLLRVRGM
     SMRDAGILDG DLIAVHRSHE ARNGQVVVAR IDDDVTVKTL RRNGPIVELL PANPDFDPIV
     VDTRSAALEL EGIMVGLIRT DH