ID   LEXA_LACGA              Reviewed;         207 AA.
AC   Q044D8;
DT   15-JAN-2008, integrated into UniProtKB/Swiss-Prot.
DT   14-NOV-2006, sequence version 1.
DT   03-AUG-2022, entry version 97.
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=LGAS_0793;
OS   Lactobacillus gasseri (strain ATCC 33323 / DSM 20243 / BCRC 14619 / CIP
OS   102991 / JCM 1131 / KCTC 3163 / NCIMB 11718 / NCTC 13722 / AM63).
OC   Bacteria; Firmicutes; Bacilli; Lactobacillales; Lactobacillaceae;
OC   Lactobacillus.
OX   NCBI_TaxID=324831;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC 33323 / DSM 20243 / BCRC 14619 / CIP 102991 / JCM 1131 / KCTC
RC   3163 / NCIMB 11718 / NCTC 13722 / AM63;
RX   PubMed=17030793; DOI=10.1073/pnas.0607117103;
RA   Makarova K.S., Slesarev A., Wolf Y.I., Sorokin A., Mirkin B., Koonin E.V.,
RA   Pavlov A., Pavlova N., Karamychev V., Polouchine N., Shakhova V.,
RA   Grigoriev I., Lou Y., Rohksar D., Lucas S., Huang K., Goodstein D.M.,
RA   Hawkins T., Plengvidhya V., Welker D., Hughes J., Goh Y., Benson A.,
RA   Baldwin K., Lee J.-H., Diaz-Muniz I., Dosti B., Smeianov V., Wechter W.,
RA   Barabote R., Lorca G., Altermann E., Barrangou R., Ganesan B., Xie Y.,
RA   Rawsthorne H., Tamir D., Parker C., Breidt F., Broadbent J.R., Hutkins R.,
RA   O'Sullivan D., Steele J., Unlu G., Saier M.H. Jr., Klaenhammer T.,
RA   Richardson P., Kozyavkin S., Weimer B.C., Mills D.A.;
RT   "Comparative genomics of the lactic acid bacteria.";
RL   Proc. Natl. Acad. Sci. U.S.A. 103:15611-15616(2006).
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; CP000413; ABJ60184.1; -; Genomic_DNA.
DR   RefSeq; WP_003647498.1; NZ_WBMG01000005.1.
DR   AlphaFoldDB; Q044D8; -.
DR   SMR; Q044D8; -.
DR   MEROPS; S24.001; -.
DR   GeneID; 66468816; -.
DR   KEGG; lga:LGAS_0793; -.
DR   HOGENOM; CLU_066192_45_1_9; -.
DR   OMA; HVWLLPH; -.
DR   OrthoDB; 1933795at2; -.
DR   BioCyc; LGAS324831:G1G6Y-787-MON; -.
DR   Proteomes; UP000000664; 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; cd00090; HTH_ARSR; 1.
DR   CDD; cd06529; S24_LexA-like; 1.
DR   Gene3D; 1.10.10.10; -; 1.
DR   HAMAP; MF_00015; LexA; 1.
DR   InterPro; IPR011991; ArsR-like_HTH.
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..207
FT                   /note="LexA repressor"
FT                   /id="PRO_1000001297"
FT   DNA_BIND        29..49
FT                   /note="H-T-H motif"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   ACT_SITE        128
FT                   /note="For autocatalytic cleavage activity"
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   SITE            92..93
FT                   /note="Cleavage; by autolysis"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
SQ   SEQUENCE   207 AA;  23048 MW;  77558F287A147694 CRC64;
     MTEPHANKQL EILRFIYDTV EERAFPPTVR EICSAVDLSS TSTVHGHLAR LEKKGYILKD
     ATKPRAIEVT EKGREALGIK PKDIPIVGVV TAGQPILAVQ DIDEYFPLPP DLENDAGELF
     MLRVHGESMI NAGILNGDHV IVRKQSSANN GEIVVAMTED NEATVKRFFK EDGYYRLQPE
     NDTMDPIILP VVQILGKVVG LYRNNID