ID   LEXA_ROSS1              Reviewed;         218 AA.
AC   A5UQF5;
DT   18-MAR-2008, integrated into UniProtKB/Swiss-Prot.
DT   18-MAR-2008, sequence version 2.
DT   03-AUG-2022, entry version 85.
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=RoseRS_0427;
OS   Roseiflexus sp. (strain RS-1).
OC   Bacteria; Chloroflexi; Chloroflexia; Chloroflexales; Roseiflexineae;
OC   Roseiflexaceae; Roseiflexus.
OX   NCBI_TaxID=357808;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=RS-1;
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   Chertkov O., Brettin T., Bruce D., Han C., Schmutz J., Larimer F., Land M.,
RA   Hauser L., Kyrpides N., Mikhailova N., Bryant D.A., Richardson P.;
RT   "Complete sequence of Roseiflexus sp. RS-1.";
RL   Submitted (APR-2007) 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}.
CC   -!- SEQUENCE CAUTION:
CC       Sequence=ABQ88858.1; Type=Erroneous initiation; Evidence={ECO:0000305};
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DR   EMBL; CP000686; ABQ88858.1; ALT_INIT; Genomic_DNA.
DR   RefSeq; WP_041332785.1; NC_009523.1.
DR   AlphaFoldDB; A5UQF5; -.
DR   SMR; A5UQF5; -.
DR   STRING; 357808.RoseRS_0427; -.
DR   MEROPS; S24.001; -.
DR   EnsemblBacteria; ABQ88858; ABQ88858; RoseRS_0427.
DR   KEGG; rrs:RoseRS_0427; -.
DR   eggNOG; COG1974; Bacteria.
DR   HOGENOM; CLU_066192_45_2_0; -.
DR   OrthoDB; 1933795at2; -.
DR   Proteomes; UP000006554; 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..218
FT                   /note="LexA repressor"
FT                   /id="PRO_0000322758"
FT   DNA_BIND        31..51
FT                   /note="H-T-H motif"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   ACT_SITE        137
FT                   /note="For autocatalytic cleavage activity"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   ACT_SITE        176
FT                   /note="For autocatalytic cleavage activity"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   SITE            95..96
FT                   /note="Cleavage; by autolysis"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
SQ   SEQUENCE   218 AA;  24280 MW;  CD8A5AE14A2D19CE CRC64;
     MRSSDQLSAR QRDILGFIEE FTQEHGYPPS IREIQDGLRI SSTSVVAYNL RALESKGLID
     RDGRVSRGIK IKNMTPMPLS RAQGGRVPLL GVITAGQPLP NPEDTSTTAV EMIEVPVDLA
     PPEKLQNVYA LKVRGHSMID ALIDDGDIVL MRYQETADNG QMVAVRIEDD NAVTLKRFYR
     EGDKVRLQPA NVTMEPIYVD AARVHIQGRV VGVLRSMW