PRELIMINARY CRYSTALLOGRAPHIC STUDIES OF THE HUMAN CYTOMEGALOVIRUS PROTEASE. Y. Li, Y. Yan, S. Munshi, D. Hall, L. Waxman, P. Darke, L. Kuo, and Z. Chen. Merck Research Laboratories, West Point, PA 19486, USA
Human cytomegalovirus (hCMV) protease is synthesized as a 709 amino-acid precursor which undergoes at least two autoprolytic cleavages. The mature protease is one of the autolytic products and is composed of the first 256 amino acids of the precursor. The active center of the hCMV protease has been proposed to contain a serine, a histidine, and a glutamate although there is no sequence homology between this protease and known serine proteases. Recent studies have showed that only the homodimeric form of the protease is active [1].
Single crystals have been obtained in our lab employing the vapor diffusion technique. These crystals grow up to 0.25x0.25x0.6 mm in tetragonal morphology. Under X-ray irradiation, the crystals diffract to well beyond 2.8 Å Braggs resolution. The cell constants are a=b=75.61 Å, and c=214.61 Å in the space group of P41212 (or P43212). There are two monomers per asymmetrical unit. A native data set has been obtained at room temperature with an Rmerge of 9.02%.
1. P. Darke, J. Cole, L. Waxman, D. L. Hall, M. K. Sardana and L.C. Kuo. (1996) J. Biol. Chem. 271, 7445-7449.