ID   LEXA_RHILO              Reviewed;         245 AA.
AC   Q98MD2;
DT   25-NOV-2002, integrated into UniProtKB/Swiss-Prot.
DT   01-OCT-2001, sequence version 1.
DT   03-AUG-2022, entry version 117.
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=mlr0626;
OS   Mesorhizobium japonicum (strain LMG 29417 / CECT 9101 / MAFF 303099)
OS   (Mesorhizobium loti (strain MAFF 303099)).
OC   Bacteria; Proteobacteria; Alphaproteobacteria; Hyphomicrobiales;
OC   Phyllobacteriaceae; Mesorhizobium.
OX   NCBI_TaxID=266835;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=LMG 29417 / CECT 9101 / MAFF 303099;
RX   PubMed=11214968; DOI=10.1093/dnares/7.6.331;
RA   Kaneko T., Nakamura Y., Sato S., Asamizu E., Kato T., Sasamoto S.,
RA   Watanabe A., Idesawa K., Ishikawa A., Kawashima K., Kimura T., Kishida Y.,
RA   Kiyokawa C., Kohara M., Matsumoto M., Matsuno A., Mochizuki Y.,
RA   Nakayama S., Nakazaki N., Shimpo S., Sugimoto M., Takeuchi C., Yamada M.,
RA   Tabata S.;
RT   "Complete genome structure of the nitrogen-fixing symbiotic bacterium
RT   Mesorhizobium loti.";
RL   DNA Res. 7:331-338(2000).
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; BA000012; BAB48181.1; -; Genomic_DNA.
DR   RefSeq; WP_010909536.1; NC_002678.2.
DR   AlphaFoldDB; Q98MD2; -.
DR   SMR; Q98MD2; -.
DR   STRING; 266835.14021569; -.
DR   MEROPS; S24.001; -.
DR   EnsemblBacteria; BAB48181; BAB48181; BAB48181.
DR   KEGG; mlo:mlr0626; -.
DR   PATRIC; fig|266835.9.peg.503; -.
DR   eggNOG; COG1974; Bacteria.
DR   HOGENOM; CLU_066192_45_2_5; -.
DR   OMA; HVWLLPH; -.
DR   OrthoDB; 1933795at2; -.
DR   Proteomes; UP000000552; 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; Repressor; SOS response; Transcription;
KW   Transcription regulation.
FT   CHAIN           1..245
FT                   /note="LexA repressor"
FT                   /id="PRO_0000170075"
FT   DNA_BIND        26..46
FT                   /note="H-T-H motif"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   ACT_SITE        166
FT                   /note="For autocatalytic cleavage activity"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   ACT_SITE        204
FT                   /note="For autocatalytic cleavage activity"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   SITE            131..132
FT                   /note="Cleavage; by autolysis"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
SQ   SEQUENCE   245 AA;  26496 MW;  F404793902739A83 CRC64;
     MLTRKQHELL MFIHERLKES GIPPSFDEMK EALDLASKSG IHRLITALEE RGFIRRLPNR
     ARALEVLRLP DSIAPGLNAA KKFSPSVIQG SLGQGGLGRQ IKPAPSRLPA AGNDDDAVSA
     VSIPVMGRIA AGVPIDAIQH QTHSISVPPD MIMGGEHYAL EVKGDSMIDA GIFDGDTVII
     RNADTASPGE IVVALVDEEE ATLKRFRRKG ASIALEAANP AYETRIFGPD RVKVQGKLVG
     LIRRY