ID   LEXA_LIMF3              Reviewed;         208 AA.
AC   B2GBL2;
DT   24-MAR-2009, integrated into UniProtKB/Swiss-Prot.
DT   10-JUN-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}; OrderedLocusNames=LAF_0708;
OS   Limosilactobacillus fermentum (strain NBRC 3956 / LMG 18251) (Lactobacillus
OS   fermentum).
OC   Bacteria; Firmicutes; Bacilli; Lactobacillales; Lactobacillaceae;
OC   Limosilactobacillus.
OX   NCBI_TaxID=334390;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=NBRC 3956 / LMG 18251;
RX   PubMed=18487258; DOI=10.1093/dnares/dsn009;
RA   Morita H., Toh H., Fukuda S., Horikawa H., Oshima K., Suzuki T.,
RA   Murakami M., Hisamatsu S., Kato Y., Takizawa T., Fukuoka H., Yoshimura T.,
RA   Itoh K., O'Sullivan D.J., McKay L.L., Ohno H., Kikuchi J., Masaoka T.,
RA   Hattori M.;
RT   "Comparative genome analysis of Lactobacillus reuteri and Lactobacillus
RT   fermentum reveal a genomic island for reuterin and cobalamin production.";
RL   DNA Res. 15:151-161(2008).
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; AP008937; BAG27044.1; -; Genomic_DNA.
DR   RefSeq; WP_003685235.1; NC_010610.1.
DR   AlphaFoldDB; B2GBL2; -.
DR   SMR; B2GBL2; -.
DR   MEROPS; S24.001; -.
DR   EnsemblBacteria; BAG27044; BAG27044; LAF_0708.
DR   GeneID; 61201043; -.
DR   KEGG; lfe:LAF_0708; -.
DR   eggNOG; COG1974; Bacteria.
DR   HOGENOM; CLU_066192_45_1_9; -.
DR   OMA; HVWLLPH; -.
DR   OrthoDB; 1933795at2; -.
DR   Proteomes; UP000001697; 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..208
FT                   /note="LexA repressor"
FT                   /id="PRO_1000089572"
FT   DNA_BIND        29..49
FT                   /note="H-T-H motif"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   ACT_SITE        129
FT                   /note="For autocatalytic cleavage activity"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   ACT_SITE        167
FT                   /note="For autocatalytic cleavage activity"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   SITE            94..95
FT                   /note="Cleavage; by autolysis"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
SQ   SEQUENCE   208 AA;  22697 MW;  33A50280B39E35DC CRC64;
     MPRNSTNKQM AVLSFIHKQV DAHGYPPTVR EICGAVGLSS TSTVHGHINR LIKKGYLKKD
     PSKPRALEIT PAGLEVLGIT PKQTQIPLLG VVAAGEPILA VQDATDFFPI PPSIPDHDDL
     FMLTIQGTSM INIGILNGDK VIVRRQETAN NGDIVIAMTS DNEATCKRFF KEQGHIRLQP
     ENDTLAPIIL DDVTILGKVV GLFRDDIF