tag visualisation by enzyme assay tag visualisation by dna adenine methyltransferase tag DNA methyltransferase MI:1185 orchard Proteins of interest are tagged with Escherichia coli DNA adenine methyltransferase (dam). Expression of this fusion protein in vivo leads to preferential methylation of adenines in DNA surrounding the native binding sites of the dam fusion partner. Because adenine methylation does not occur endogenously in most eukaryotes, it provides a unique tag to mark protein interaction sites. The adenine-methylated DNA fragments are isolated by selective polymerase chain reaction amplification and can be identified by microarray hybridization. PSI-MI 2012-06-07T02:22:19Z