ID   LEXA_ACIF2              Reviewed;         205 AA.
AC   B7JBX0;
DT   14-APR-2009, integrated into UniProtKB/Swiss-Prot.
DT   10-FEB-2009, sequence version 1.
DT   03-AUG-2022, entry version 74.
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=AFE_1868;
OS   Acidithiobacillus ferrooxidans (strain ATCC 23270 / DSM 14882 / CIP 104768
OS   / NCIMB 8455) (Ferrobacillus ferrooxidans (strain ATCC 23270)).
OC   Bacteria; Proteobacteria; Acidithiobacillia; Acidithiobacillales;
OC   Acidithiobacillaceae; Acidithiobacillus.
OX   NCBI_TaxID=243159;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC 23270 / DSM 14882 / CIP 104768 / NCIMB 8455;
RX   PubMed=19077236; DOI=10.1186/1471-2164-9-597;
RA   Valdes J., Pedroso I., Quatrini R., Dodson R.J., Tettelin H., Blake R. II,
RA   Eisen J.A., Holmes D.S.;
RT   "Acidithiobacillus ferrooxidans metabolism: from genome sequence to
RT   industrial applications.";
RL   BMC Genomics 9:597-597(2008).
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; CP001219; ACK78330.1; -; Genomic_DNA.
DR   RefSeq; WP_009568876.1; NC_011761.1.
DR   AlphaFoldDB; B7JBX0; -.
DR   SMR; B7JBX0; -.
DR   STRING; 243159.AFE_1868; -.
DR   MEROPS; S24.001; -.
DR   PaxDb; B7JBX0; -.
DR   EnsemblBacteria; ACK78330; ACK78330; AFE_1868.
DR   GeneID; 66432640; -.
DR   KEGG; afr:AFE_1868; -.
DR   eggNOG; COG1974; Bacteria.
DR   HOGENOM; CLU_066192_45_3_6; -.
DR   OMA; HVWLLPH; -.
DR   OrthoDB; 1933795at2; -.
DR   Proteomes; UP000001362; 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..205
FT                   /note="LexA repressor"
FT                   /id="PRO_1000192763"
FT   DNA_BIND        28..48
FT                   /note="H-T-H motif"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   ACT_SITE        120
FT                   /note="For autocatalytic cleavage activity"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   ACT_SITE        159
FT                   /note="For autocatalytic cleavage activity"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   SITE            85..86
FT                   /note="Cleavage; by autolysis"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
SQ   SEQUENCE   205 AA;  22626 MW;  2B87862389A3461E CRC64;
     MDELTPRQSE ILAWIRARMA EDSLPPTRAE LMRAFDFRSP NAAESHLRVL ARKGYILLQS
     GTARGIRLCA SEEETGLPLI GRVAAGQPML AEEFREGQLP VDPKLFSPGA DYLLRVQGMS
     MRDAGILDGD ILAVRHDASL TLQDGQMVVA RVNGEVTVKR WKRDGKQVWL LPENPDFSPI
     SVDLQRDSLT IEGVVVGLLR IGGNL