ID   LEXA_PETMO              Reviewed;         205 AA.
AC   A9BGA3;
DT   20-MAY-2008, integrated into UniProtKB/Swiss-Prot.
DT   15-JAN-2008, sequence version 1.
DT   03-AUG-2022, entry version 89.
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=Pmob_1237;
OS   Petrotoga mobilis (strain DSM 10674 / SJ95).
OC   Bacteria; Thermotogae; Petrotogales; Petrotogaceae; Petrotoga.
OX   NCBI_TaxID=403833;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=DSM 10674 / SJ95;
RG   US DOE Joint Genome Institute;
RA   Copeland A., Lucas S., Lapidus A., Barry K., Glavina del Rio T., Dalin E.,
RA   Tice H., Pitluck S., Meincke L., Brettin T., Bruce D., Detter J.C., Han C.,
RA   Kuske C.R., Schmutz J., Larimer F., Land M., Hauser L., Kyrpides N.,
RA   Mikhailova N., Noll K., Richardson P.;
RT   "Complete sequence of Petroga mobilis SJ95.";
RL   Submitted (NOV-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; CP000879; ABX31953.1; -; Genomic_DNA.
DR   RefSeq; WP_012209053.1; NC_010003.1.
DR   AlphaFoldDB; A9BGA3; -.
DR   SMR; A9BGA3; -.
DR   STRING; 403833.Pmob_1237; -.
DR   MEROPS; S24.001; -.
DR   EnsemblBacteria; ABX31953; ABX31953; Pmob_1237.
DR   KEGG; pmo:Pmob_1237; -.
DR   eggNOG; COG1974; Bacteria.
DR   HOGENOM; CLU_066192_45_1_0; -.
DR   OMA; HVWLLPH; -.
DR   OrthoDB; 1933795at2; -.
DR   Proteomes; UP000000789; Chromosome.
DR   CollecTF; EXPREG_000002c0; -.
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; Repressor; SOS response; Transcription;
KW   Transcription regulation.
FT   CHAIN           1..205
FT                   /note="LexA repressor"
FT                   /id="PRO_1000074061"
FT   DNA_BIND        28..48
FT                   /note="H-T-H motif"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   ACT_SITE        125
FT                   /note="For autocatalytic cleavage activity"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   ACT_SITE        163
FT                   /note="For autocatalytic cleavage activity"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   SITE            89..90
FT                   /note="Cleavage; by autolysis"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
SQ   SEQUENCE   205 AA;  23336 MW;  725E6044016A10FA CRC64;
     MEELTKRQSQ VLDFIKSYME KNGFAPSIRD IMKHFNFKSP RAAHKHLIIL EKKGYIERKN
     VSRGIKMMPK SGEIFATETL APVSGKIAAG DAIEAIQTIS DYIPIPTNFF PKNYEYFSLR
     VEGNSMIEAQ IKSGDFVLIR KQDYAMDGDI VVALIDGNDA TLKRYKRLNE DEVLLIPENK
     SMKEIKVKAD HLKIQGKMVG LIRVL