ID   LEXA_ALTMD              Reviewed;         208 AA.
AC   B4S1W7; F2G510;
DT   24-MAR-2009, integrated into UniProtKB/Swiss-Prot.
DT   23-SEP-2008, sequence version 1.
DT   03-AUG-2022, entry version 95.
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=MADE_1020110;
OS   Alteromonas mediterranea (strain DSM 17117 / CIP 110805 / LMG 28347 / Deep
OS   ecotype).
OC   Bacteria; Proteobacteria; Gammaproteobacteria; Alteromonadales;
OC   Alteromonadaceae; Alteromonas/Salinimonas group; Alteromonas.
OX   NCBI_TaxID=1774373;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=DSM 17117 / CIP 110805 / LMG 28347 / Deep ecotype;
RX   PubMed=18670397; DOI=10.1038/ismej.2008.74;
RA   Ivars-Martinez E., Martin-Cuadrado A.-B., D'Auria G., Mira A., Ferriera S.,
RA   Johnson J., Friedman R., Rodriguez-Valera F.;
RT   "Comparative genomics of two ecotypes of the marine planktonic copiotroph
RT   Alteromonas macleodii suggests alternative lifestyles associated with
RT   different kinds of particulate organic matter.";
RL   ISME J. 2:1194-1212(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; CP001103; AEB00145.1; -; Genomic_DNA.
DR   RefSeq; WP_012518730.1; NC_011138.3.
DR   AlphaFoldDB; B4S1W7; -.
DR   SMR; B4S1W7; -.
DR   MEROPS; S24.001; -.
DR   EnsemblBacteria; AEB00145; AEB00145; MADE_1020110.
DR   GeneID; 56344236; -.
DR   KEGG; amc:MADE_1020110; -.
DR   HOGENOM; CLU_066192_45_3_6; -.
DR   OMA; HVWLLPH; -.
DR   Proteomes; UP000001870; 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_1000089543"
FT   DNA_BIND        28..48
FT                   /note="H-T-H motif"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   ACT_SITE        125
FT                   /note="For autocatalytic cleavage activity"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   ACT_SITE        162
FT                   /note="For autocatalytic cleavage activity"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   SITE            90..91
FT                   /note="Cleavage; by autolysis"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
SQ   SEQUENCE   208 AA;  22976 MW;  951DB715DC683771 CRC64;
     MRPLTARQTE VLELIKTTMQ ETGMPPTRAE IARQLGFRSA NAAEEHLKAL ARKGVIEILP
     GTSRGIKLNI PLDNEAEEEE GLPLIGRVAA GEPILAQEHV ESHYKVDPAL FQPQADFLLR
     VNGMSMKDIG ILDGDLLAVH RTTDVHNGQV VVARVDEDVT VKRLEKRGRE VLLHAENEEF
     SPIKVDLANE PFAIEGIAVG VIRNADWM