ID   LEXA_METRJ              Reviewed;         242 AA.
AC   B1LUJ7;
DT   24-MAR-2009, integrated into UniProtKB/Swiss-Prot.
DT   29-APR-2008, 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};
GN   OrderedLocusNames=Mrad2831_2020;
OS   Methylobacterium radiotolerans (strain ATCC 27329 / DSM 1819 / JCM 2831 /
OS   NBRC 15690 / NCIMB 10815 / 0-1).
OC   Bacteria; Proteobacteria; Alphaproteobacteria; Hyphomicrobiales;
OC   Methylobacteriaceae; Methylobacterium.
OX   NCBI_TaxID=426355;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC 27329 / DSM 1819 / JCM 2831 / NBRC 15690 / NCIMB 10815 / 0-1;
RG   US DOE Joint Genome Institute;
RA   Copeland A., Lucas S., Lapidus A., Glavina del Rio T., Dalin E., Tice H.,
RA   Bruce D., Goodwin L., Pitluck S., Kiss H., Brettin T., Detter J.C., Han C.,
RA   Kuske C.R., Schmutz J., Larimer F., Land M., Hauser L., Kyrpides N.,
RA   Mikhailova N., Marx C.J., Richardson P.;
RT   "Complete sequence of chromosome of Methylobacterium radiotolerans JCM
RT   2831.";
RL   Submitted (MAR-2008) 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; CP001001; ACB24015.1; -; Genomic_DNA.
DR   RefSeq; WP_012318999.1; NC_010505.1.
DR   AlphaFoldDB; B1LUJ7; -.
DR   SMR; B1LUJ7; -.
DR   STRING; 426355.Mrad2831_2020; -.
DR   MEROPS; S24.001; -.
DR   EnsemblBacteria; ACB24015; ACB24015; Mrad2831_2020.
DR   KEGG; mrd:Mrad2831_2020; -.
DR   eggNOG; COG1974; Bacteria.
DR   HOGENOM; CLU_066192_45_2_5; -.
DR   OMA; EGVFCGL; -.
DR   OrthoDB; 1933795at2; -.
DR   Proteomes; UP000006589; 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..242
FT                   /note="LexA repressor"
FT                   /id="PRO_1000089578"
FT   DNA_BIND        26..46
FT                   /note="H-T-H motif"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   REGION          75..109
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   ACT_SITE        163
FT                   /note="For autocatalytic cleavage activity"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   ACT_SITE        201
FT                   /note="For autocatalytic cleavage activity"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   SITE            128..129
FT                   /note="Cleavage; by autolysis"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
SQ   SEQUENCE   242 AA;  26519 MW;  E2C1DFA5B7BBB426 CRC64;
     MLTRKQLDLL RFIQSRMQEC GVPPSFDEMK DALDLKSKSG IHRLITALEE RGFLRRLPNR
     ARAIEVIRIP ESLTQAAPAP QTPAEPRRFT PSVVEGGKSK QPPAPASTRM IDESGRAISI
     PVMGRIAAGT PVSAIQNQSH AITLSPDFVA GGEHYALEVR GDSMVEAGIL DGDLVVIRKQ
     DTANTGDIIV ALIDDEEATL KRLRRRGSSI ALEAANPAYE TRVLGPDRVR IQGRLVSLVR
     RY