THE STRUCTURE OF MAMMALIAN HEXOKINASE-1

We have determined the structures of the glucose-6-phosphate (G6P)-inh ibitable 100,000 M-r Type I hexokinase from rat and the G6P-sensitive 50,000 M-r hexokinase from Schistosoma mansoni at a resolution of 2.8 and 2.6 Angstrom respectively. The structures define the glucose and G 6P binding sites in these enzymes, suggest the mechanisms of intradoma in G6P inhibition and activity loss in the Type I hexokinase N-termina l half, and reveal the structure of the membrane targeting motif that integrates the Type I hexokinase into the outer mitochondrial membrane .