ID   LEXA_RUEST              Reviewed;         241 AA.
AC   Q1GHJ8;
DT   15-JAN-2008, integrated into UniProtKB/Swiss-Prot.
DT   27-JUN-2006, sequence version 1.
DT   03-AUG-2022, entry version 105.
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=TM1040_1135;
OS   Ruegeria sp. (strain TM1040) (Silicibacter sp.).
OC   Bacteria; Proteobacteria; Alphaproteobacteria; Rhodobacterales;
OC   Roseobacteraceae; Ruegeria; unclassified Ruegeria.
OX   NCBI_TaxID=292414;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=TM1040;
RG   US DOE Joint Genome Institute;
RA   Copeland A., Lucas S., Lapidus A., Barry K., Detter J.C.,
RA   Glavina del Rio T., Hammon N., Israni S., Dalin E., Tice H., Pitluck S.,
RA   Brettin T., Bruce D., Han C., Tapia R., Goodwin L., Thompson L.S.,
RA   Gilna P., Schmutz J., Larimer F., Land M., Hauser L., Kyrpides N., Kim E.,
RA   Belas R., Moran M.A., Buchan A., Gonzalez J.M., Schell M.A., Sun F.,
RA   Richardson P.;
RT   "Complete sequence of chromosome of Silicibacter sp. TM1040.";
RL   Submitted (MAY-2006) 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; CP000377; ABF63868.1; -; Genomic_DNA.
DR   RefSeq; WP_011538475.1; NC_008044.1.
DR   AlphaFoldDB; Q1GHJ8; -.
DR   SMR; Q1GHJ8; -.
DR   STRING; 292414.TM1040_1135; -.
DR   MEROPS; S24.001; -.
DR   EnsemblBacteria; ABF63868; ABF63868; TM1040_1135.
DR   KEGG; sit:TM1040_1135; -.
DR   eggNOG; COG1974; Bacteria.
DR   HOGENOM; CLU_066192_45_2_5; -.
DR   OMA; HVWLLPH; -.
DR   OrthoDB; 1933795at2; -.
DR   Proteomes; UP000000636; 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..241
FT                   /note="LexA repressor"
FT                   /id="PRO_1000001347"
FT   DNA_BIND        26..46
FT                   /note="H-T-H motif"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   ACT_SITE        162
FT                   /note="For autocatalytic cleavage activity"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   ACT_SITE        200
FT                   /note="For autocatalytic cleavage activity"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   SITE            126..127
FT                   /note="Cleavage; by autolysis"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
SQ   SEQUENCE   241 AA;  25705 MW;  DE325A001C0BCE20 CRC64;
     MLTKKQLQLL EFIHKRLQKD GVPPSFDEMK TALDLRSKSG IHRLITALEE RGFIRRLAHR
     ARAIEVIRLP DSLGGGGALG AASDGFQPKV IAGGRGDSAD GGAAAELKPV ADTGATELTI
     MGRIAAGVPI EAINQAAAHV AVPNAMLSSS GQHYALEVRG DSMIDAGIND GDVVVIRETD
     AADNGDIVVA LVEGHEATLK RFERKGRMIE LHAANPAYPT RSYTEDQVKV QGRLVGLIRT
     Y