ID   LEXA_RHOPA              Reviewed;         236 AA.
AC   P61614;
DT   24-MAY-2004, integrated into UniProtKB/Swiss-Prot.
DT   24-MAY-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=RPA2903;
OS   Rhodopseudomonas palustris (strain ATCC BAA-98 / CGA009).
OC   Bacteria; Proteobacteria; Alphaproteobacteria; Hyphomicrobiales;
OC   Bradyrhizobiaceae; Rhodopseudomonas.
OX   NCBI_TaxID=258594;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC BAA-98 / CGA009;
RX   PubMed=14704707; DOI=10.1038/nbt923;
RA   Larimer F.W., Chain P., Hauser L., Lamerdin J.E., Malfatti S., Do L.,
RA   Land M.L., Pelletier D.A., Beatty J.T., Lang A.S., Tabita F.R.,
RA   Gibson J.L., Hanson T.E., Bobst C., Torres y Torres J.L., Peres C.,
RA   Harrison F.H., Gibson J., Harwood C.S.;
RT   "Complete genome sequence of the metabolically versatile photosynthetic
RT   bacterium Rhodopseudomonas palustris.";
RL   Nat. Biotechnol. 22:55-61(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}.
CC   -!- SEQUENCE CAUTION:
CC       Sequence=CAE28344.1; Type=Erroneous initiation; Evidence={ECO:0000305};
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DR   EMBL; BX572602; CAE28344.1; ALT_INIT; Genomic_DNA.
DR   RefSeq; WP_012496347.1; NC_005296.1.
DR   AlphaFoldDB; P61614; -.
DR   SMR; P61614; -.
DR   STRING; 258594.RPA2903; -.
DR   MEROPS; S24.001; -.
DR   PRIDE; P61614; -.
DR   EnsemblBacteria; CAE28344; CAE28344; RPA2903.
DR   GeneID; 66893985; -.
DR   KEGG; rpa:RPA2903; -.
DR   eggNOG; COG1974; Bacteria.
DR   HOGENOM; CLU_066192_45_2_5; -.
DR   PhylomeDB; P61614; -.
DR   BioCyc; RPAL258594:TX73_RS14805-MON; -.
DR   Proteomes; UP000001426; 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..236
FT                   /note="LexA repressor"
FT                   /id="PRO_0000170078"
FT   DNA_BIND        26..46
FT                   /note="H-T-H motif"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   REGION          85..109
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   ACT_SITE        157
FT                   /note="For autocatalytic cleavage activity"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   ACT_SITE        195
FT                   /note="For autocatalytic cleavage activity"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   SITE            122..123
FT                   /note="Cleavage; by autolysis"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
SQ   SEQUENCE   236 AA;  25912 MW;  2B2156AD0DBB4731 CRC64;
     MLTRKQFELL KFINERLKEA GVPPSFDEMK DALDLRSKSG IHRLITALEE RGFIRRLPNR
     ARAIEVIKLP DTGGMPGNSR RGFTPSVIEG NLGKVRPPSP TPAEDDHDRG SVAVPVMGRI
     AAGTPIEALQ SRSHTISVPA DMLGSGEHYA LEVRGDSMVE AGILDGDMAL IQKNDVADTG
     DIVVALIDEE EATLKRFRRR GASIALEPAN AAYEVRILPP NRVRIQGKLI GLYRKY