InterPro domain: IPR029056

This superfamily represents a domain found in phosphotransferases that have an alcohol group as an acceptor ([intenz:2.7.1.-]). However, 4-amino-5-hydroxymethyl-2-methylpyrimidine phosphate kinase (HMPP kinase) catalyses two phosphorylation reactions: one to a hydroxymethyl group of hydroxymethyl pyrimidine (HMP) and the second to the phosphomethyl group of HMPP [ 1 ]. The common structural feature for the enzymes in this superfamily is a central eight-stranded sheet that is flanked by eight structurally conserved helices, five on one side and three on the other [ 2 ]. The active site is located in a shallow groove along one edge of the sheet, with the phosphate acceptor hydroxyl group and -phosphate of ATP close together in the middle of the groove, and substrate and ATP binding at the ends [ 2 ].

1. Crystal structure of an aminoimidazole riboside kinase from Salmonella enterica: implications for the evolution of the ribokinase superfamily. Structure 12, 1809-21