ID   LEXA_AZOC5              Reviewed;         236 AA.
AC   A8I825;
DT   26-FEB-2008, integrated into UniProtKB/Swiss-Prot.
DT   04-DEC-2007, sequence version 1.
DT   03-AUG-2022, entry version 80.
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=AZC_2201;
OS   Azorhizobium caulinodans (strain ATCC 43989 / DSM 5975 / JCM 20966 / LMG
OS   6465 / NBRC 14845 / NCIMB 13405 / ORS 571).
OC   Bacteria; Proteobacteria; Alphaproteobacteria; Hyphomicrobiales;
OC   Xanthobacteraceae; Azorhizobium.
OX   NCBI_TaxID=438753;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC 43989 / DSM 5975 / JCM 20966 / LMG 6465 / NBRC 14845 / NCIMB
RC   13405 / ORS 571;
RA   Lee K.B., Backer P.D., Aono T., Liu C.T., Suzuki S., Suzuki T., Kaneko T.,
RA   Yamada M., Tabata S., Kupfer D.M., Najar F.Z., Wiley G.B., Roe B.,
RA   Binnewies T., Ussery D., Vereecke D., Gevers D., Holsters M., Oyaizu H.;
RT   "Complete genome sequence of the nitrogen-fixing bacterium Azorhizobium
RT   caulinodans ORS571.";
RL   Submitted (APR-2007) 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; AP009384; BAF88199.1; -; Genomic_DNA.
DR   RefSeq; WP_012170728.1; NC_009937.1.
DR   AlphaFoldDB; A8I825; -.
DR   SMR; A8I825; -.
DR   STRING; 438753.AZC_2201; -.
DR   MEROPS; S24.001; -.
DR   EnsemblBacteria; BAF88199; BAF88199; AZC_2201.
DR   KEGG; azc:AZC_2201; -.
DR   eggNOG; COG1974; Bacteria.
DR   HOGENOM; CLU_066192_45_2_5; -.
DR   OMA; HVWLLPH; -.
DR   OrthoDB; 1933795at2; -.
DR   Proteomes; UP000000270; 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..236
FT                   /note="LexA repressor"
FT                   /id="PRO_1000070964"
FT   DNA_BIND        26..46
FT                   /note="H-T-H motif"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   ACT_SITE        157
FT                   /note="For autocatalytic cleavage activity"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   ACT_SITE        195
FT                   /note="For autocatalytic cleavage activity"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   SITE            122..123
FT                   /note="Cleavage; by autolysis"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
SQ   SEQUENCE   236 AA;  25740 MW;  646B2187ABF24E91 CRC64;
     MLTRKQYDLL RFIHERLKET GVPPSFDEMK EALDLRSKSG IHRLITALEE RGFIRRLPNR
     ARALEVVRLP DSAAPGLAAA RSGGRGFSPS VIEGSLGRVR PVVDDEEPAA VVAVPVMGRI
     AAGSPISAIQ TRSNTLNLPP EMLGTGEHFA LEVRGDSMIE AGILDGDTVL IRKCDTADTG
     DIIVALVDDE EATLKRLRRK GASIALEAAN PAYETRIFGP DRVRIQGRLV GLIRRY