ID   LEXA_HALHL              Reviewed;         226 AA.
AC   A1WXU3;
DT   15-JAN-2008, integrated into UniProtKB/Swiss-Prot.
DT   06-FEB-2007, sequence version 1.
DT   03-AUG-2022, entry version 88.
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=Hhal_1741;
OS   Halorhodospira halophila (strain DSM 244 / SL1) (Ectothiorhodospira
OS   halophila (strain DSM 244 / SL1)).
OC   Bacteria; Proteobacteria; Gammaproteobacteria; Chromatiales;
OC   Ectothiorhodospiraceae; Halorhodospira.
OX   NCBI_TaxID=349124;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=DSM 244 / SL1;
RG   US DOE Joint Genome Institute;
RA   Copeland A., Lucas S., Lapidus A., Barry K., Detter J.C.,
RA   Glavina del Rio T., Hammon N., Israni S., Dalin E., Tice H., Pitluck S.,
RA   Saunders E., Brettin T., Bruce D., Han C., Tapia R., Schmutz J.,
RA   Larimer F., Land M., Hauser L., Kyrpides N., Mikhailova N., Hoff W.,
RA   Richardson P.;
RT   "Complete sequence of Halorhodospira halophila SL1.";
RL   Submitted (DEC-2006) to the EMBL/GenBank/DDBJ databases.
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; CP000544; ABM62505.1; -; Genomic_DNA.
DR   RefSeq; WP_011814527.1; NC_008789.1.
DR   AlphaFoldDB; A1WXU3; -.
DR   SMR; A1WXU3; -.
DR   STRING; 349124.Hhal_1741; -.
DR   MEROPS; S24.001; -.
DR   PRIDE; A1WXU3; -.
DR   EnsemblBacteria; ABM62505; ABM62505; Hhal_1741.
DR   KEGG; hha:Hhal_1741; -.
DR   eggNOG; COG1974; Bacteria.
DR   HOGENOM; CLU_066192_45_3_6; -.
DR   OMA; HVWLLPH; -.
DR   OrthoDB; 1933795at2; -.
DR   Proteomes; UP000000647; 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..226
FT                   /note="LexA repressor"
FT                   /id="PRO_1000001293"
FT   DNA_BIND        28..48
FT                   /note="H-T-H motif"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   ACT_SITE        133
FT                   /note="For autocatalytic cleavage activity"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   ACT_SITE        170
FT                   /note="For autocatalytic cleavage activity"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   SITE            98..99
FT                   /note="Cleavage; by autolysis"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
SQ   SEQUENCE   226 AA;  24308 MW;  E3C06F31F4E731A2 CRC64;
     MDTLTDRQRE ILELIRRSVA ERGYPPTRAE ICQSLGFRSP NAAESHLRAL ARKGAIEMRR
     GASRGIRLTD AFAGAAPEPS PATDDPNAGL PVVGRVAAGS PLLAEESIER YCQVDASLFS
     PPADYLLRVR GESMRDAGIL DGDLLAVRRD TEARDGQIVV VRLHDEVTVK FLERCNGVLR
     LIPAHPDYPV IEVAADGQDA VLEGIGVGVL RSPLDPRGPE GNAASD