ID   OGT_PYRHO               Reviewed;         172 AA.
AC   O59499;
DT   10-MAY-2004, integrated into UniProtKB/Swiss-Prot.
DT   10-MAY-2004, sequence version 2.
DT   25-MAY-2022, entry version 107.
DE   RecName: Full=Methylated-DNA--protein-cysteine methyltransferase {ECO:0000250|UniProtKB:O74023};
DE            EC=2.1.1.63 {ECO:0000250|UniProtKB:O74023};
DE   AltName: Full=6-O-methylguanine-DNA methyltransferase {ECO:0000250|UniProtKB:O74023};
DE            Short=MGMT {ECO:0000250|UniProtKB:O74023};
DE   AltName: Full=O-6-methylguanine-DNA-alkyltransferase {ECO:0000250|UniProtKB:O74023};
GN   Name=ogt {ECO:0000250|UniProtKB:O74023}; OrderedLocusNames=PH1835;
OS   Pyrococcus horikoshii (strain ATCC 700860 / DSM 12428 / JCM 9974 / NBRC
OS   100139 / OT-3).
OC   Archaea; Euryarchaeota; Thermococci; Thermococcales; Thermococcaceae;
OC   Pyrococcus.
OX   NCBI_TaxID=70601;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC 700860 / DSM 12428 / JCM 9974 / NBRC 100139 / OT-3;
RX   PubMed=9679194; DOI=10.1093/dnares/5.2.55;
RA   Kawarabayasi Y., Sawada M., Horikawa H., Haikawa Y., Hino Y., Yamamoto S.,
RA   Sekine M., Baba S., Kosugi H., Hosoyama A., Nagai Y., Sakai M., Ogura K.,
RA   Otsuka R., Nakazawa H., Takamiya M., Ohfuku Y., Funahashi T., Tanaka T.,
RA   Kudoh Y., Yamazaki J., Kushida N., Oguchi A., Aoki K., Yoshizawa T.,
RA   Nakamura Y., Robb F.T., Horikoshi K., Masuchi Y., Shizuya H., Kikuchi H.;
RT   "Complete sequence and gene organization of the genome of a hyper-
RT   thermophilic archaebacterium, Pyrococcus horikoshii OT3.";
RL   DNA Res. 5:55-76(1998).
CC   -!- FUNCTION: Involved in the cellular defense against the biological
CC       effects of O6-methylguanine (O6-MeG) and O4-methylthymine (O4-MeT) in
CC       DNA. Repairs the methylated nucleobase in DNA by stoichiometrically
CC       transferring the methyl group to a cysteine residue in the enzyme. This
CC       is a suicide reaction: the enzyme is irreversibly inactivated.
CC       {ECO:0000250|UniProtKB:O74023}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=a 6-O-methyl-2'-deoxyguanosine in DNA + L-cysteinyl-[protein]
CC         = a 2'-deoxyguanosine in DNA + S-methyl-L-cysteinyl-[protein];
CC         Xref=Rhea:RHEA:24000, Rhea:RHEA-COMP:10131, Rhea:RHEA-COMP:10132,
CC         Rhea:RHEA-COMP:11367, Rhea:RHEA-COMP:11368, ChEBI:CHEBI:29950,
CC         ChEBI:CHEBI:82612, ChEBI:CHEBI:85445, ChEBI:CHEBI:85448; EC=2.1.1.63;
CC         Evidence={ECO:0000250|UniProtKB:O74023};
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=a 4-O-methyl-thymidine in DNA + L-cysteinyl-[protein] = a
CC         thymidine in DNA + S-methyl-L-cysteinyl-[protein];
CC         Xref=Rhea:RHEA:53428, Rhea:RHEA-COMP:10131, Rhea:RHEA-COMP:10132,
CC         Rhea:RHEA-COMP:13555, Rhea:RHEA-COMP:13556, ChEBI:CHEBI:29950,
CC         ChEBI:CHEBI:82612, ChEBI:CHEBI:137386, ChEBI:CHEBI:137387;
CC         EC=2.1.1.63; Evidence={ECO:0000250|UniProtKB:O74023};
CC   -!- SUBCELLULAR LOCATION: Cytoplasm {ECO:0000250|UniProtKB:O74023}.
CC   -!- MISCELLANEOUS: This enzyme catalyzes only one turnover and therefore is
CC       not strictly catalytic. According to one definition, an enzyme is a
CC       biocatalyst that acts repeatedly and over many reaction cycles.
CC       {ECO:0000250|UniProtKB:O74023}.
CC   -!- SIMILARITY: Belongs to the MGMT family. {ECO:0000250|UniProtKB:O74023}.
CC   -!- SEQUENCE CAUTION:
CC       Sequence=BAA30955.1; Type=Erroneous initiation; Evidence={ECO:0000305};
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DR   EMBL; BA000001; BAA30955.1; ALT_INIT; Genomic_DNA.
DR   PIR; D71195; D71195.
DR   RefSeq; WP_048053490.1; NC_000961.1.
DR   AlphaFoldDB; O59499; -.
DR   SMR; O59499; -.
DR   STRING; 70601.3258272; -.
DR   EnsemblBacteria; BAA30955; BAA30955; BAA30955.
DR   GeneID; 1442676; -.
DR   KEGG; pho:PH1835; -.
DR   eggNOG; arCOG02724; Archaea.
DR   OMA; KRNPYPI; -.
DR   OrthoDB; 122341at2157; -.
DR   Proteomes; UP000000752; Chromosome.
DR   GO; GO:0005737; C:cytoplasm; IEA:UniProtKB-SubCell.
DR   GO; GO:0003908; F:methylated-DNA-[protein]-cysteine S-methyltransferase activity; IEA:UniProtKB-EC.
DR   GO; GO:0006281; P:DNA repair; IEA:UniProtKB-KW.
DR   GO; GO:0032259; P:methylation; IEA:UniProtKB-KW.
DR   CDD; cd06445; ATase; 1.
DR   Gene3D; 1.10.10.10; -; 1.
DR   InterPro; IPR001497; MethylDNA_cys_MeTrfase_AS.
DR   InterPro; IPR014048; MethylDNA_cys_MeTrfase_DNA-bd.
DR   InterPro; IPR036217; MethylDNA_cys_MeTrfase_DNAb.
DR   InterPro; IPR015236; MGMT_N.
DR   InterPro; IPR036631; MGMT_N_sf.
DR   InterPro; IPR036388; WH-like_DNA-bd_sf.
DR   Pfam; PF01035; DNA_binding_1; 1.
DR   Pfam; PF09153; DUF1938; 1.
DR   SUPFAM; SSF46767; SSF46767; 1.
DR   SUPFAM; SSF53155; SSF53155; 1.
DR   TIGRFAMs; TIGR00589; ogt; 1.
DR   PROSITE; PS00374; MGMT; 1.
PE   3: Inferred from homology;
KW   Cytoplasm; DNA damage; DNA repair; Methyltransferase; Transferase.
FT   CHAIN           1..172
FT                   /note="Methylated-DNA--protein-cysteine methyltransferase"
FT                   /id="PRO_0000139384"
FT   ACT_SITE        142
FT                   /note="Nucleophile; methyl group acceptor"
FT                   /evidence="ECO:0000250|UniProtKB:O74023"
SQ   SEQUENCE   172 AA;  19614 MW;  27268B6F8E6A4400 CRC64;
     MLTYKTFKIL GREILIGVVW EEKIQGIAYS LDGLEFLKDQ LSRVTSHLKS RGVKVNLLEE
     KSRYPDLVFD VLKGKIGNEK GFEELSLEGL TRFEIKVYSW LVKNVKRGEV ITYGKVAKAL
     KTSPIAVGGA MKRNPYPIIV PCHRVVGKNN PWLYTPKPSY KKFLLEVEGW IS