LEXA_THEMA
ID LEXA_THEMA Reviewed; 197 AA.
AC O33927;
DT 30-MAY-2000, integrated into UniProtKB/Swiss-Prot.
DT 01-JAN-1998, sequence version 1.
DT 03-AUG-2022, entry version 147.
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=TM_1082;
OS Thermotoga maritima (strain ATCC 43589 / DSM 3109 / JCM 10099 / NBRC 100826
OS / MSB8).
OC Bacteria; Thermotogae; Thermotogales; Thermotogaceae; Thermotoga.
OX NCBI_TaxID=243274;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC STRAIN=ATCC 43589 / DSM 3109 / JCM 10099 / NBRC 100826 / MSB8;
RX PubMed=9380682; DOI=10.1073/pnas.94.20.10606;
RA Guipaud O., Marguet E., Noll K.M., Bouthier de la Tour C., Forterre P.;
RT "Both DNA gyrase and reverse gyrase are present in the hyperthermophilic
RT bacterium Thermotoga maritima.";
RL Proc. Natl. Acad. Sci. U.S.A. 94:10606-10611(1997).
RN [2]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=ATCC 43589 / DSM 3109 / JCM 10099 / NBRC 100826 / MSB8;
RX PubMed=10360571; DOI=10.1038/20601;
RA Nelson K.E., Clayton R.A., Gill S.R., Gwinn M.L., Dodson R.J., Haft D.H.,
RA Hickey E.K., Peterson J.D., Nelson W.C., Ketchum K.A., McDonald L.A.,
RA Utterback T.R., Malek J.A., Linher K.D., Garrett M.M., Stewart A.M.,
RA Cotton M.D., Pratt M.S., Phillips C.A., Richardson D.L., Heidelberg J.F.,
RA Sutton G.G., Fleischmann R.D., Eisen J.A., White O., Salzberg S.L.,
RA Smith H.O., Venter J.C., Fraser C.M.;
RT "Evidence for lateral gene transfer between Archaea and Bacteria from
RT genome sequence of Thermotoga maritima.";
RL Nature 399:323-329(1999).
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 -!- MISCELLANEOUS: No consensus sequence similar to the SOS-box from E.coli
CC or from B.subtilis was found upstream of the lexA gene, suggesting the
CC presence of another target sequence specific for the Thermotogales.
CC -!- SIMILARITY: Belongs to the peptidase S24 family. {ECO:0000255|HAMAP-
CC Rule:MF_00015}.
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DR EMBL; U76417; AAB87145.1; -; Genomic_DNA.
DR EMBL; AE000512; AAD36159.1; -; Genomic_DNA.
DR PIR; B72297; B72297.
DR RefSeq; NP_228888.1; NC_000853.1.
DR RefSeq; WP_004080401.1; NZ_CP011107.1.
DR PDB; 3K2Z; X-ray; 1.37 A; A/B=3-197.
DR PDBsum; 3K2Z; -.
DR AlphaFoldDB; O33927; -.
DR SMR; O33927; -.
DR STRING; 243274.THEMA_08945; -.
DR MEROPS; S24.001; -.
DR DNASU; 897745; -.
DR EnsemblBacteria; AAD36159; AAD36159; TM_1082.
DR KEGG; tma:TM1082; -.
DR eggNOG; COG1974; Bacteria.
DR InParanoid; O33927; -.
DR OMA; HVWLLPH; -.
DR OrthoDB; 1933795at2; -.
DR EvolutionaryTrace; O33927; -.
DR Proteomes; UP000008183; 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 1: Evidence at protein level;
KW 3D-structure; Autocatalytic cleavage; DNA damage; DNA repair;
KW DNA replication; DNA-binding; Hydrolase; Reference proteome; Repressor;
KW SOS response; Transcription; Transcription regulation.
FT CHAIN 1..197
FT /note="LexA repressor"
FT /id="PRO_0000170098"
FT DNA_BIND 28..47
FT /note="H-T-H motif"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT ACT_SITE 119
FT /note="For autocatalytic cleavage activity"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT ACT_SITE 156
FT /note="For autocatalytic cleavage activity"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT SITE 83..84
FT /note="Cleavage; by autolysis"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00015"
FT HELIX 6..22
FT /evidence="ECO:0007829|PDB:3K2Z"
FT HELIX 28..35
FT /evidence="ECO:0007829|PDB:3K2Z"
FT HELIX 39..51
FT /evidence="ECO:0007829|PDB:3K2Z"
FT STRAND 54..56
FT /evidence="ECO:0007829|PDB:3K2Z"
FT HELIX 58..60
FT /evidence="ECO:0007829|PDB:3K2Z"
FT STRAND 66..69
FT /evidence="ECO:0007829|PDB:3K2Z"
FT STRAND 74..83
FT /evidence="ECO:0007829|PDB:3K2Z"
FT HELIX 85..87
FT /evidence="ECO:0007829|PDB:3K2Z"
FT STRAND 89..98
FT /evidence="ECO:0007829|PDB:3K2Z"
FT HELIX 101..103
FT /evidence="ECO:0007829|PDB:3K2Z"
FT STRAND 110..114
FT /evidence="ECO:0007829|PDB:3K2Z"
FT HELIX 121..123
FT /evidence="ECO:0007829|PDB:3K2Z"
FT STRAND 130..135
FT /evidence="ECO:0007829|PDB:3K2Z"
FT STRAND 144..149
FT /evidence="ECO:0007829|PDB:3K2Z"
FT STRAND 152..161
FT /evidence="ECO:0007829|PDB:3K2Z"
FT STRAND 164..168
FT /evidence="ECO:0007829|PDB:3K2Z"
FT STRAND 177..180
FT /evidence="ECO:0007829|PDB:3K2Z"
FT HELIX 181..183
FT /evidence="ECO:0007829|PDB:3K2Z"
FT STRAND 185..196
FT /evidence="ECO:0007829|PDB:3K2Z"
SQ SEQUENCE 197 AA; 22864 MW; A8093B0BB3D10BFB CRC64;
MKDLTERQRK VLLFIEEFIE KNGYPPSVRE IARRFRITPR GALLHLIALE KKGYIERKNG
KPRALRISKS IRNKIPLIGE IRAGEKREAI EYLEDYIEIP ESFLSSGYDH FLLKVKGESM
IEEHICDGDL VLVRRQDWAQ NGDIVAAMVD GEVTLKKFYQ RGDTVELRPA NREMSSMFFR
AEKVKILGKV VGVFRKL
