The catalytic mechanism of protein tyrosine phosphatases revisited

Experimental and theoretical studies of the catalytic mechanism in protein tyrosine phosphatases and dual specific phosphatases are reviewed. The stru ctural properties of these enzymes contributing to the efficient rate enhan cement of phosphate monoester hydrolysis have been established during the l ast decade. There are, however, uncertainties in the interpretation of avai lable experimental data that make the commonly assumed reaction mechanism s omewhat doubtful. Theoretical calculations as well as analysis of crystal s tructures point towards an alternative interpretation of the ionisation sta te in the reactive complex. (C) 2001 Federation of European Biochemical Soc ieties. Published by Elsevier Science B,V, All rights reserved.