ID   LEXA_METSB              Reviewed;         236 AA.
AC   B8EK86;
DT   28-JUL-2009, integrated into UniProtKB/Swiss-Prot.
DT   03-MAR-2009, sequence version 1.
DT   03-AUG-2022, entry version 77.
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=Msil_1678;
OS   Methylocella silvestris (strain DSM 15510 / CIP 108128 / LMG 27833 / NCIMB
OS   13906 / BL2).
OC   Bacteria; Proteobacteria; Alphaproteobacteria; Hyphomicrobiales;
OC   Beijerinckiaceae; Methylocella.
OX   NCBI_TaxID=395965;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=DSM 15510 / CIP 108128 / LMG 27833 / NCIMB 13906 / BL2;
RX   PubMed=20472789; DOI=10.1128/jb.00506-10;
RA   Chen Y., Crombie A., Rahman M.T., Dedysh S.N., Liesack W., Stott M.B.,
RA   Alam M., Theisen A.R., Murrell J.C., Dunfield P.F.;
RT   "Complete genome sequence of the aerobic facultative methanotroph
RT   Methylocella silvestris BL2.";
RL   J. Bacteriol. 192:3840-3841(2010).
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}.
CC   ---------------------------------------------------------------------------
CC   Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms
CC   Distributed under the Creative Commons Attribution (CC BY 4.0) License
CC   ---------------------------------------------------------------------------
DR   EMBL; CP001280; ACK50626.1; -; Genomic_DNA.
DR   RefSeq; WP_012590696.1; NC_011666.1.
DR   AlphaFoldDB; B8EK86; -.
DR   SMR; B8EK86; -.
DR   STRING; 395965.Msil_1678; -.
DR   MEROPS; S24.001; -.
DR   EnsemblBacteria; ACK50626; ACK50626; Msil_1678.
DR   KEGG; msl:Msil_1678; -.
DR   eggNOG; COG1974; Bacteria.
DR   HOGENOM; CLU_066192_45_2_5; -.
DR   OMA; HVWLLPH; -.
DR   OrthoDB; 1933795at2; -.
DR   Proteomes; UP000002257; 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..236
FT                   /note="LexA repressor"
FT                   /id="PRO_1000116610"
FT   DNA_BIND        26..46
FT                   /note="H-T-H motif"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   ACT_SITE        157
FT                   /note="For autocatalytic cleavage activity"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   ACT_SITE        195
FT                   /note="For autocatalytic cleavage activity"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   SITE            122..123
FT                   /note="Cleavage; by autolysis"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
SQ   SEQUENCE   236 AA;  26129 MW;  399669EF7E5B4784 CRC64;
     MLTKKQSELL RFINERMKET GVPPSFDEMK DALDLRSKSG IHRLIIALEE RGFIRRLPNR
     ARALEVLRMP GASAADAGRG RKFEPSVIEG HLGRVRPMPA ARDDEDGARA MVAIPVMGRI
     AAGTPISALQ TRSHTLNLPP EMLSQGEHYA LEVRGDSMID AGIFDADTVL IRKQDTAETG
     DIVVALIDDE EATLKRLRRR GASIALEAAN PAYETRIFGP DRVRIQGKLV GLIRRY