ID   LEXA_CITBB              Reviewed;         201 AA.
AC   B5EA68;
DT   24-MAR-2009, integrated into UniProtKB/Swiss-Prot.
DT   14-OCT-2008, sequence version 1.
DT   03-AUG-2022, entry version 82.
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=Gbem_1758;
OS   Citrifermentans bemidjiense (strain ATCC BAA-1014 / DSM 16622 / JCM 12645 /
OS   Bem) (Geobacter bemidjiensis).
OC   Bacteria; Proteobacteria; Deltaproteobacteria; Desulfuromonadales;
OC   Geobacteraceae; Citrifermentans.
OX   NCBI_TaxID=404380;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC BAA-1014 / DSM 16622 / JCM 12645 / Bem;
RG   US DOE Joint Genome Institute;
RA   Lucas S., Copeland A., 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   Lykidis A., Lovley D., Richardson P.;
RT   "Complete sequence of Geobacter bemidjiensis BEM.";
RL   Submitted (JUL-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; CP001124; ACH38774.1; -; Genomic_DNA.
DR   RefSeq; WP_012530192.1; NC_011146.1.
DR   AlphaFoldDB; B5EA68; -.
DR   SMR; B5EA68; -.
DR   STRING; 404380.Gbem_1758; -.
DR   MEROPS; S24.001; -.
DR   EnsemblBacteria; ACH38774; ACH38774; Gbem_1758.
DR   KEGG; gbm:Gbem_1758; -.
DR   eggNOG; COG1974; Bacteria.
DR   HOGENOM; CLU_066192_45_1_7; -.
DR   OMA; HVWLLPH; -.
DR   OrthoDB; 1933795at2; -.
DR   Proteomes; UP000008825; 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..201
FT                   /note="LexA repressor"
FT                   /id="PRO_1000089568"
FT   DNA_BIND        28..48
FT                   /note="H-T-H motif"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   ACT_SITE        120
FT                   /note="For autocatalytic cleavage activity"
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   SITE            85..86
FT                   /note="Cleavage; by autolysis"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
SQ   SEQUENCE   201 AA;  22227 MW;  D21FB87C452E9219 CRC64;
     MEQLTARQTE VLQIITRHLE TCGYPPTLRE IAAQLGISGT LGVMKHLEAL EKKGYLRRQE
     GSTRGITLCN QSQAASLPIV GVVRAGLLHP AIQDIEGHFA IDRSQLASGG AFFLRVKGDS
     MVHAHIVEGD LALVRPQPHA SNRDIVVAMV DGEATLKRFY READRIRLQP ENPNYEPIII
     EKGEQEVSIV GKVVGIYRQM E