ID   LEXA_MAGMM              Reviewed;         231 AA.
AC   A0L9E2;
DT   18-MAR-2008, integrated into UniProtKB/Swiss-Prot.
DT   12-DEC-2006, sequence version 1.
DT   03-AUG-2022, entry version 97.
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=Mmc1_2084;
OS   Magnetococcus marinus (strain ATCC BAA-1437 / JCM 17883 / MC-1).
OC   Bacteria; Proteobacteria; Alphaproteobacteria; Magnetococcales;
OC   Magnetococcaceae; Magnetococcus.
OX   NCBI_TaxID=156889;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC BAA-1437 / JCM 17883 / MC-1;
RX   PubMed=19465526; DOI=10.1128/aem.02874-08;
RA   Schubbe S., Williams T.J., Xie G., Kiss H.E., Brettin T.S., Martinez D.,
RA   Ross C.A., Schuler D., Cox B.L., Nealson K.H., Bazylinski D.A.;
RT   "Complete genome sequence of the chemolithoautotrophic marine magnetotactic
RT   coccus strain MC-1.";
RL   Appl. Environ. Microbiol. 75:4835-4852(2009).
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; CP000471; ABK44585.1; -; Genomic_DNA.
DR   RefSeq; WP_011713713.1; NC_008576.1.
DR   AlphaFoldDB; A0L9E2; -.
DR   SMR; A0L9E2; -.
DR   STRING; 156889.Mmc1_2084; -.
DR   MEROPS; S24.001; -.
DR   EnsemblBacteria; ABK44585; ABK44585; Mmc1_2084.
DR   KEGG; mgm:Mmc1_2084; -.
DR   eggNOG; COG1974; Bacteria.
DR   HOGENOM; CLU_066192_45_1_5; -.
DR   OMA; HVWLLPH; -.
DR   OrthoDB; 1933795at2; -.
DR   Proteomes; UP000002586; Chromosome.
DR   CollecTF; EXPREG_00000160; -.
DR   GO; GO:0032993; C:protein-DNA complex; IMP:CollecTF.
DR   GO; GO:0043565; F:sequence-specific DNA binding; IMP:CollecTF.
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_0000322741"
FT   DNA_BIND        43..62
FT                   /note="H-T-H motif"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   REGION          1..24
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   ACT_SITE        146
FT                   /note="For autocatalytic cleavage activity"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   ACT_SITE        183
FT                   /note="For autocatalytic cleavage activity"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   SITE            112..113
FT                   /note="Cleavage; by autolysis"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
SQ   SEQUENCE   231 AA;  25480 MW;  E6D6F111801F50D7 CRC64;
     MTDRKEHKMK PGRRPTEGMT PSQERIMQVI RNAIDRDGLP PTVKEIAEAL GMKTPSAHEQ
     VQKLVKKGFI RRTPRKARSI EIVEQSPEEE PVEKKPDVAR LVPVPIIGEV AAGIPILAVE
     NHIGELLMDS RTARGPCFAL KVKGDSMIDA EIFEGDYVVV RHQALAENGD IVVAILDGEA
     TVKRLYISEE TIELRPENRS YQPIVVPPGG DIRILGKVLA VRGHGAANNN E