ID   LEXA_MOOTA              Reviewed;         205 AA.
AC   Q2RJF5;
DT   05-FEB-2008, integrated into UniProtKB/Swiss-Prot.
DT   24-JAN-2006, sequence version 1.
DT   03-AUG-2022, entry version 104.
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=Moth_1120;
OS   Moorella thermoacetica (strain ATCC 39073 / JCM 9320).
OC   Bacteria; Firmicutes; Clostridia; Thermoanaerobacterales;
OC   Thermoanaerobacteraceae; Moorella group; Moorella.
OX   NCBI_TaxID=264732;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC 39073 / JCM 9320;
RX   PubMed=18631365; DOI=10.1111/j.1462-2920.2008.01679.x;
RA   Pierce E., Xie G., Barabote R.D., Saunders E., Han C.S., Detter J.C.,
RA   Richardson P., Brettin T.S., Das A., Ljungdahl L.G., Ragsdale S.W.;
RT   "The complete genome sequence of Moorella thermoacetica (f. Clostridium
RT   thermoaceticum).";
RL   Environ. Microbiol. 10:2550-2573(2008).
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; CP000232; ABC19434.1; -; Genomic_DNA.
DR   RefSeq; WP_011392634.1; NC_007644.1.
DR   RefSeq; YP_429977.1; NC_007644.1.
DR   AlphaFoldDB; Q2RJF5; -.
DR   SMR; Q2RJF5; -.
DR   STRING; 264732.Moth_1120; -.
DR   MEROPS; S24.001; -.
DR   EnsemblBacteria; ABC19434; ABC19434; Moth_1120.
DR   KEGG; mta:Moth_1120; -.
DR   PATRIC; fig|264732.11.peg.1201; -.
DR   eggNOG; COG1974; Bacteria.
DR   HOGENOM; CLU_066192_45_1_9; -.
DR   OMA; HVWLLPH; -.
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; Repressor; SOS response; Transcription;
KW   Transcription regulation.
FT   CHAIN           1..205
FT                   /note="LexA repressor"
FT                   /id="PRO_1000057133"
FT   DNA_BIND        29..49
FT                   /note="H-T-H motif"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   ACT_SITE        128
FT                   /note="For autocatalytic cleavage activity"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   ACT_SITE        165
FT                   /note="For autocatalytic cleavage activity"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   SITE            93..94
FT                   /note="Cleavage; by autolysis"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
SQ   SEQUENCE   205 AA;  22832 MW;  F51B368E5B24C97B CRC64;
     MQPDLSPQLA MVLNYIRHFI DINGYPPSIR DICKATGLRS SSTVYNYLNK LEEKGYIRRD
     PSRSRAIEIL TPYPALTRAK NMVSVPLLGK ITAGQPILAF ENIEDVFPLP ADLAGAENAF
     MLHVSGDSMI EAGILDGDYL IVRPQDTAEN GDIVVALLED EATVKYFYRY PDHIELVPAN
     SSMQPLIVHK VTILGKVVGL YRHFS