ID   LEXA_BACCR              Reviewed;         206 AA.
AC   Q81A92;
DT   25-JUL-2003, integrated into UniProtKB/Swiss-Prot.
DT   18-MAR-2008, sequence version 2.
DT   03-AUG-2022, entry version 119.
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=BC_3690;
OS   Bacillus cereus (strain ATCC 14579 / DSM 31 / CCUG 7414 / JCM 2152 / NBRC
OS   15305 / NCIMB 9373 / NCTC 2599 / NRRL B-3711).
OC   Bacteria; Firmicutes; Bacilli; Bacillales; Bacillaceae; Bacillus;
OC   Bacillus cereus group.
OX   NCBI_TaxID=226900;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC 14579 / DSM 31 / CCUG 7414 / JCM 2152 / NBRC 15305 / NCIMB 9373
RC   / NCTC 2599 / NRRL B-3711;
RX   PubMed=12721630; DOI=10.1038/nature01582;
RA   Ivanova N., Sorokin A., Anderson I., Galleron N., Candelon B., Kapatral V.,
RA   Bhattacharyya A., Reznik G., Mikhailova N., Lapidus A., Chu L., Mazur M.,
RA   Goltsman E., Larsen N., D'Souza M., Walunas T., Grechkin Y., Pusch G.,
RA   Haselkorn R., Fonstein M., Ehrlich S.D., Overbeek R., Kyrpides N.C.;
RT   "Genome sequence of Bacillus cereus and comparative analysis with Bacillus
RT   anthracis.";
RL   Nature 423:87-91(2003).
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=AAP10619.1; Type=Erroneous initiation; Evidence={ECO:0000305};
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DR   EMBL; AE016877; AAP10619.1; ALT_INIT; Genomic_DNA.
DR   RefSeq; NP_833418.1; NC_004722.1.
DR   RefSeq; WP_000413738.1; NZ_CP034551.1.
DR   AlphaFoldDB; Q81A92; -.
DR   SMR; Q81A92; -.
DR   STRING; 226900.BC_3690; -.
DR   MEROPS; S24.001; -.
DR   EnsemblBacteria; AAP10619; AAP10619; BC_3690.
DR   GeneID; 59155806; -.
DR   GeneID; 64202240; -.
DR   GeneID; 67508337; -.
DR   KEGG; bce:BC3690; -.
DR   PATRIC; fig|226900.8.peg.3795; -.
DR   HOGENOM; CLU_066192_45_1_9; -.
DR   OMA; HVWLLPH; -.
DR   Proteomes; UP000001417; 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..206
FT                   /note="LexA repressor"
FT                   /id="PRO_0000170004"
FT   DNA_BIND        28..48
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        166
FT                   /note="For autocatalytic cleavage activity"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT   SITE            92..93
FT                   /note="Cleavage; by autolysis"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
SQ   SEQUENCE   206 AA;  22890 MW;  CC4077E937DF8D09 CRC64;
     MEKLTKRQQD ILDFIKLKVQ EKGYPPSVRE IGQAVGLASS STVHGHLSRL EEKGYIRRDP
     TKPRAIEILG EDRMDTETQS VIQVPIVGKV TAGLPITAVE SVEEHFPLPA SIVAGADQVF
     MLRISGDSMI EAGIFDGDLV VVRQQQSAYN GEIVVALTED NEATVKRFYK EKDHFRLQPE
     NSSLEPIILK QVSVIGKVIG VYRDLH