ID   LEXA_RHORT              Reviewed;         251 AA.
AC   Q2RT47;
DT   18-MAR-2008, integrated into UniProtKB/Swiss-Prot.
DT   24-JAN-2006, sequence version 1.
DT   03-AUG-2022, entry version 103.
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=Rru_A1898;
OS   Rhodospirillum rubrum (strain ATCC 11170 / ATH 1.1.1 / DSM 467 / LMG 4362 /
OS   NCIMB 8255 / S1).
OC   Bacteria; Proteobacteria; Alphaproteobacteria; Rhodospirillales;
OC   Rhodospirillaceae; Rhodospirillum.
OX   NCBI_TaxID=269796;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC 11170 / ATH 1.1.1 / DSM 467 / LMG 4362 / NCIMB 8255 / S1;
RX   PubMed=21886856; DOI=10.4056/sigs.1804360;
RA   Munk A.C., Copeland A., Lucas S., Lapidus A., Del Rio T.G., Barry K.,
RA   Detter J.C., Hammon N., Israni S., Pitluck S., Brettin T., Bruce D.,
RA   Han C., Tapia R., Gilna P., Schmutz J., Larimer F., Land M., Kyrpides N.C.,
RA   Mavromatis K., Richardson P., Rohde M., Goeker M., Klenk H.P., Zhang Y.,
RA   Roberts G.P., Reslewic S., Schwartz D.C.;
RT   "Complete genome sequence of Rhodospirillum rubrum type strain (S1).";
RL   Stand. Genomic Sci. 4:293-302(2011).
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; CP000230; ABC22698.1; -; Genomic_DNA.
DR   RefSeq; WP_011389651.1; NC_007643.1.
DR   RefSeq; YP_426985.1; NC_007643.1.
DR   AlphaFoldDB; Q2RT47; -.
DR   SMR; Q2RT47; -.
DR   STRING; 269796.Rru_A1898; -.
DR   MEROPS; S24.001; -.
DR   EnsemblBacteria; ABC22698; ABC22698; Rru_A1898.
DR   KEGG; rru:Rru_A1898; -.
DR   PATRIC; fig|269796.9.peg.1979; -.
DR   eggNOG; COG1974; Bacteria.
DR   HOGENOM; CLU_066192_45_2_5; -.
DR   OMA; EGVFCGL; -.
DR   OrthoDB; 1933795at2; -.
DR   PhylomeDB; Q2RT47; -.
DR   Proteomes; UP000001929; 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..251
FT                   /note="LexA repressor"
FT                   /id="PRO_0000322757"
FT   DNA_BIND        26..46
FT                   /note="H-T-H motif"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   ACT_SITE        172
FT                   /note="For autocatalytic cleavage activity"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   ACT_SITE        210
FT                   /note="For autocatalytic cleavage activity"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   SITE            137..138
FT                   /note="Cleavage; by autolysis"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
SQ   SEQUENCE   251 AA;  27250 MW;  BB1649C68A38144A CRC64;
     MLTRKQYLLL SFIDQRLKLS GVSPSFDEMK DALGLKSKSG IHRLIKGLEE RGFLKRLPHR
     ARALEVLRLP CNLTFDGDGE ALDDGQPAPL FGGPLPETGF SPQVIRGNFT PTLPSTQVPQ
     VLFTESISLP LLGKIAAGTP IAALIDPTSS IDVPASMVRG GEHFALRIEG DSMIEAGILS
     GDLAVVRRCD EAENGTVIVA LVDNEEATLK RLRRKGASIA LEPANRAFKT QIYGPDRVRI
     QGRLVGLIRS Y