Evolutionary origin of aminoglycoside phosphotransferase resistance genes.

The protein sequences of seven 3'-aminoglycoside phosphotransferases falling into the six identified types and three 6'-aminoglycoside phosphotransferases were analyzed to give a rooted phylogenetic tree. This tree supports the origin of these groups of enzymes in an ancestor closely related to the actinomycetes, and that horizontal transfer of the resistance genes occurred, possibly via transposons. The implications for genetic engineering of a novel antibiotic are discussed.