MGMTDNA T. en ribbon model of MethylatedDNAproteincysteine methyltransferase MGMT with DNA methylguanin shown as balls after PDB Ref Daniels et al DNA binding and nucleotide flipping by the human DNA repair protein AGT Nat Struct Mol Biol PMID DOI adapted from pdb org pdb using PyMOL own work ebi ac uk Transferases