X-ray structure of glycerol kinase complexed with an ATP analog implies a novel mechanism for the ATP-dependent glycerol phosphorylation by glycerol kinase

Glycerol kinase (GK) catalyzes the Mg-ATP-dependent phosphorylation of glyc erol which yields glycerol 3-phosphate. The 2.8 Angstrom new crystal struct ure of GK complexed with an ATP analog revealed an unexpected position of t he gamma-phosphoryl group, which was 7.2 Angstrom distant from the 3-hydrox yl group of glycerol, 5.5 A away from the 3-phosphate of the product (glyce rol 3-phosphate) and is stabilized by a beta-hairpin structure. Based on th e presented crystal structure and the previously determined structures of G K product complexes, we propose a 3-D model of a nucleophilic inline transf er mechanism for the ATP-dependent phosphorylation of glycerol by GK. (C) 1 999 Academic Press.