ID   LEXA_XANCI              Reviewed;         213 AA.
AC   P60512; O86050;
DT   01-MAR-2004, integrated into UniProtKB/Swiss-Prot.
DT   01-MAR-2004, sequence version 1.
DT   03-AUG-2022, entry version 84.
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};
OS   Xanthomonas citri (Xanthomonas campestris pv. citri).
OC   Bacteria; Proteobacteria; Gammaproteobacteria; Xanthomonadales;
OC   Xanthomonadaceae; Xanthomonas.
OX   NCBI_TaxID=346;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA], AND DNA-BINDING SPECIFICITY.
RC   STRAIN=XW47;
RX   PubMed=10688691; DOI=10.1007/s002849910047;
RA   Yang M.-K., Wu P.-I., Yang Y.-C.;
RT   "Identification of a lexA gene in, and construction of a lexA mutant of,
RT   Xanthomonas campestris pv. citri.";
RL   Curr. Microbiol. 40:233-238(2000).
CC   -!- FUNCTION: Represses a number of genes involved in the response to DNA
CC       damage (SOS response), including recA and lexA. Has been shown to bind
CC       to the palindromic sequence 5'-CTG-N(8-12)-C-[TC]-G. 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 (By
CC       similarity). {ECO:0000250}.
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; AF081945; AAC31950.1; -; Genomic_DNA.
DR   RefSeq; WP_005915033.1; NZ_SMDV01000012.1.
DR   AlphaFoldDB; P60512; -.
DR   SMR; P60512; -.
DR   MEROPS; S24.001; -.
DR   GeneID; 66910889; -.
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   1: Evidence at protein level;
KW   Autocatalytic cleavage; DNA damage; DNA repair; DNA replication;
KW   DNA-binding; Hydrolase; Repressor; SOS response; Transcription;
KW   Transcription regulation.
FT   CHAIN           1..213
FT                   /note="LexA repressor"
FT                   /id="PRO_0000170108"
FT   DNA_BIND        27..47
FT                   /note="H-T-H motif"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   ACT_SITE        133
FT                   /note="For autocatalytic cleavage activity"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   ACT_SITE        170
FT                   /note="For autocatalytic cleavage activity"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   SITE            98..99
FT                   /note="Cleavage; by autolysis"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
SQ   SEQUENCE   213 AA;  23240 MW;  30C56E5396EAF946 CRC64;
     MDLTDTQQAI LALIAERIDA DGVPPSQTEI ARAFGFKGIR AAQYHLEALE HAGAIRRVPG
     QARGIRLAGQ GAQTRTAPVS EVARDDVLRL PVLGRVAAGL PIGADIGSDD FVVLDRVFFS
     PSPDYLLKVQ GDSMRDEGIF NGDLIGVHRT RDARSGQIVV ARIDEEITVK LLKIGKDRIR
     LLPRNPDYAP IEVLPDQDFA IEGLYCGLLR PNR