ID   LEXA_HYPNA              Reviewed;         227 AA.
AC   Q0C1A3;
DT   15-JAN-2008, integrated into UniProtKB/Swiss-Prot.
DT   17-OCT-2006, sequence version 1.
DT   03-AUG-2022, entry version 111.
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=HNE_1786;
OS   Hyphomonas neptunium (strain ATCC 15444).
OC   Bacteria; Proteobacteria; Alphaproteobacteria; Hyphomonadales;
OC   Hyphomonadaceae; Hyphomonas.
OX   NCBI_TaxID=228405;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC 15444;
RX   PubMed=16980487; DOI=10.1128/jb.00111-06;
RA   Badger J.H., Hoover T.R., Brun Y.V., Weiner R.M., Laub M.T., Alexandre G.,
RA   Mrazek J., Ren Q., Paulsen I.T., Nelson K.E., Khouri H.M., Radune D.,
RA   Sosa J., Dodson R.J., Sullivan S.A., Rosovitz M.J., Madupu R.,
RA   Brinkac L.M., Durkin A.S., Daugherty S.C., Kothari S.P., Giglio M.G.,
RA   Zhou L., Haft D.H., Selengut J.D., Davidsen T.M., Yang Q., Zafar N.,
RA   Ward N.L.;
RT   "Comparative genomic evidence for a close relationship between the
RT   dimorphic prosthecate bacteria Hyphomonas neptunium and Caulobacter
RT   crescentus.";
RL   J. Bacteriol. 188:6841-6850(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; CP000158; ABI75849.1; -; Genomic_DNA.
DR   RefSeq; WP_011646790.1; NC_008358.1.
DR   AlphaFoldDB; Q0C1A3; -.
DR   SMR; Q0C1A3; -.
DR   STRING; 228405.HNE_1786; -.
DR   MEROPS; S24.001; -.
DR   EnsemblBacteria; ABI75849; ABI75849; HNE_1786.
DR   KEGG; hne:HNE_1786; -.
DR   eggNOG; COG1974; Bacteria.
DR   HOGENOM; CLU_066192_45_2_5; -.
DR   OMA; HVWLLPH; -.
DR   OrthoDB; 1933795at2; -.
DR   Proteomes; UP000001959; 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..227
FT                   /note="LexA repressor"
FT                   /id="PRO_1000001294"
FT   DNA_BIND        26..46
FT                   /note="H-T-H motif"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   ACT_SITE        147
FT                   /note="For autocatalytic cleavage activity"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   ACT_SITE        185
FT                   /note="For autocatalytic cleavage activity"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   SITE            112..113
FT                   /note="Cleavage; by autolysis"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
SQ   SEQUENCE   227 AA;  24672 MW;  A03601B015D39470 CRC64;
     MLTTKQKELL LFINDRIKDT GVSPSFDEMK EALDLASKSG IHRLITALEE RGFIRRLANR
     ARALEVLKLP DSAIPPPNAR QRRDFRPALV TNQGAEAPRI AGMIPLVGRI AAGSPISAIQ
     QENGQVASPG GLPEGDDYFA LEVQGDSMIQ AGILNGDTVI LKRTNTAQTG DIVVALIDGE
     EATLKRLRRK GASVALEAAN PAFETRIFGP DRVEVQGRLV ALIRRYE