LEXA_SYMTH
ID LEXA_SYMTH Reviewed; 205 AA.
AC Q67NM2;
DT 01-FEB-2005, integrated into UniProtKB/Swiss-Prot.
DT 11-OCT-2004, sequence version 1.
DT 03-AUG-2022, entry version 104.
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=STH1736;
OS Symbiobacterium thermophilum (strain T / IAM 14863).
OC Bacteria; Firmicutes; Clostridia; Eubacteriales; Symbiobacteriaceae;
OC Symbiobacterium.
OX NCBI_TaxID=292459;
RN [1]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=T / IAM 14863;
RX PubMed=15383646; DOI=10.1093/nar/gkh830;
RA Ueda K., Yamashita A., Ishikawa J., Shimada M., Watsuji T., Morimura K.,
RA Ikeda H., Hattori M., Beppu T.;
RT "Genome sequence of Symbiobacterium thermophilum, an uncultivable bacterium
RT that depends on microbial commensalism.";
RL Nucleic Acids Res. 32:4937-4944(2004).
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; AP006840; BAD40721.1; -; Genomic_DNA.
DR RefSeq; WP_011195864.1; NC_006177.1.
DR AlphaFoldDB; Q67NM2; -.
DR SMR; Q67NM2; -.
DR STRING; 292459.STH1736; -.
DR MEROPS; S24.001; -.
DR EnsemblBacteria; BAD40721; BAD40721; STH1736.
DR KEGG; sth:STH1736; -.
DR eggNOG; COG1974; Bacteria.
DR HOGENOM; CLU_066192_45_1_9; -.
DR OMA; HVWLLPH; -.
DR OrthoDB; 1933795at2; -.
DR Proteomes; UP000000417; 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; cd00090; HTH_ARSR; 1.
DR CDD; cd06529; S24_LexA-like; 1.
DR Gene3D; 1.10.10.10; -; 1.
DR HAMAP; MF_00015; LexA; 1.
DR InterPro; IPR011991; ArsR-like_HTH.
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..205
FT /note="LexA repressor"
FT /id="PRO_0000170097"
FT DNA_BIND 29..49
FT /note="H-T-H motif"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT ACT_SITE 128
FT /note="For autocatalytic cleavage activity"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT ACT_SITE 165
FT /note="For autocatalytic cleavage activity"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT SITE 91..92
FT /note="Cleavage; by autolysis"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
SQ SEQUENCE 205 AA; 23097 MW; 8CAD209C0B362258 CRC64;
MPEPLTERQR QILQFIKDEI RTKGYPPSVR EIGEAIGLSS SSTVHGHMTR LEEKGYIRRD
PTKPRAIEVL DGSHTQLKRT IAVPVVGRVT AGQPILAQES IEDHFPLPAD FVRADESELF
FLTVQGDSMI EAGILDGDYV LVHRQQHANN GDIVVALIED EATVKRFFKE QDHIRLQPEN
RFMDPIIVPD CQILGKVVGL VRRMG
