A Phosphotransferase Gene encodes one of a large group of enzymes that transfer phosphate, diphosphate, nucleotidyl residues, and other groups. Many phosphotransferases catalyze the conversion of a proenzyme to an active enzyme or catalyze the transfer of phosphate groups to form triphosphates (e.g., ATP). Phosphotransferases have also been subdivided according to the acceptor group. [ ]