O6-methylguanine-DNA Methyltransferase (human, recombinant)

O6-methylguanine-DNA Methyltransferase (MGMT) is a DNA repair enzyme responsible for demethylating O6-methylguanine (O6-mG). The methylation of guanine at O6 to form O6-mG allows base-pairing to thymine rather than cytosine during DNA replication. MGMT prevents mutations by transferring the methyl group from O6-mG to MGMT cysteine 145, restoring guanine. This transfer results in a covalent bond between MGMT cysteine 145 and the methyl group, and so MGMT is a single-turnover, "suicide" enzyme. The assay used to test MGMT is the demethylation of a synthesized, double-stranded, DNA oligonucleotide. Demethylation removes an O6-methyl group to expose a restriction site for the restriction endonuclease PvuII. Lanes A-E show 200 ng of methylated dsDNA treated with increasing amounts of MGMT prior to PvuII digestion.Synonyms: MGMT. Purity: >50% estimated by SDS-PAGE. Source: Recombinant N-terminal His-tagged protein expressed in E. coli. Amino Acids: 2-238 (full length). MW: 26.8 kDa. Formulation: (Request formulation change), 50 mM Tris, pH 8.0, 150 mM sodium chloride, 10% glycerol. UniProt Accession #: B4DEE8.