| Type: | Active_site | Name: | Methylated-DNA-[protein]-cysteine S-methyltransferase, active site |
| Description: | Synonym(s): 6-O-methylguanine-DNA methyltransferase, O-6-methylguanine-DNA-alkyltransferase, Methylated-DNA-[protein]-cysteine S-methyltransferase.This entry represents the active site of 6-O-methylguanine-DNA methyltransferases.The repair of DNA containing O6-alkylated guanine is carried out by DNA-[protein]-cysteine S-methyltransferase (). The major mutagenic and carcinogenic effect of methylating agents in DNA is the formation of O6-alkylguanine. The alkyl group at the O-6 position is transferred to a cysteine residue in the enzyme []. This is a suicide reaction since the enzyme is irreversibly inactivatedand the methylated protein accumulates as a dead-end product. Most, but not all of the methyltransferases are also able to repair O-4-methylthymine. DNA-[protein]-cysteine S-methyltransferases are widely distributed and are found in various prokaryotic and eukaryotic sources []. | Short Name: | MethylDNA_cys_MeTrfase_AS |
