Crystallization and preliminary crystal analysis of yeast hexokinase PI and PII.

Hexokinase is the prime enzyme of the Embden-Meyerhof pathway and is responsible for the first stage of energy conversion. It catalyzes the transfer of a phosphate to glucose to form glucose-6-phosphate. Yeast hexokinase PII is also known to play an important role in glucose signal transduction. Crystals of yeast hexokinase isoforms PI and PII were obtained by vapour-diffusion techniques using the hanging-drop method. Isoform PI crystals belong to the space group P2(1)2(1)2(1), with unit-cell parameters a = 62.12, b = 78.87, c = 144.74 A. Unit-cell parameters for isoform PII crystals are a = b = 142.81, c = 58.46 A and the space group is I4. Synchrotron diffraction data have been collected to 2.2 A resolution from the isoform PII crystal, whereas isoform PI diffracted to 3.1 A.