ID   LEXA_HAEIG              Reviewed;         207 AA.
AC   A5UHQ3;
DT   15-JAN-2008, integrated into UniProtKB/Swiss-Prot.
DT   10-JUL-2007, 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};
GN   OrderedLocusNames=CGSHiGG_07240;
OS   Haemophilus influenzae (strain PittGG).
OC   Bacteria; Proteobacteria; Gammaproteobacteria; Pasteurellales;
OC   Pasteurellaceae; Haemophilus.
OX   NCBI_TaxID=374931;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=PittGG;
RX   PubMed=17550610; DOI=10.1186/gb-2007-8-6-r103;
RA   Hogg J.S., Hu F.Z., Janto B., Boissy R., Hayes J., Keefe R., Post J.C.,
RA   Ehrlich G.D.;
RT   "Characterization and modeling of the Haemophilus influenzae core and
RT   supragenomes based on the complete genomic sequences of Rd and 12 clinical
RT   nontypeable strains.";
RL   Genome Biol. 8:R103.1-R103.18(2007).
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; CP000672; ABR00309.1; -; Genomic_DNA.
DR   RefSeq; WP_005648504.1; NC_009567.1.
DR   AlphaFoldDB; A5UHQ3; -.
DR   SMR; A5UHQ3; -.
DR   MEROPS; S24.001; -.
DR   EnsemblBacteria; ABR00309; ABR00309; CGSHiGG_07240.
DR   KEGG; hiq:CGSHiGG_07240; -.
DR   HOGENOM; CLU_066192_45_3_6; -.
DR   OMA; HVWLLPH; -.
DR   Proteomes; UP000001990; 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..207
FT                   /note="LexA repressor"
FT                   /id="PRO_1000001290"
FT   DNA_BIND        28..48
FT                   /note="H-T-H motif"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   ACT_SITE        123
FT                   /note="For autocatalytic cleavage activity"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   ACT_SITE        160
FT                   /note="For autocatalytic cleavage activity"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   SITE            88..89
FT                   /note="Cleavage; by autolysis"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
SQ   SEQUENCE   207 AA;  23020 MW;  849F721D8AD5C7D7 CRC64;
     MRPLTARQQE VLDLLKRHLE TTGMPPTRAE ISRELGFKSA NAAEEHLKAL SRKGAIEIIP
     GASRGIRILD NSSNDEFDGL PLVGRVAAGE PILAEQHIEA TYRVDADMFK PQADFLLKVY
     GLSMKNVGIL DGDLLAVHST KDVRNGQIVV ARIEDEVTVK RLEKKGSIIY LHAENEEFDP
     IVVNLEEQKN FEIEGIAVGI IRNNAWM