CRYSTALLIZATION AND PRELIMINARY CRYSTALLOGRAPHIC ANALYSIS OF STREPTOMYCES-GRISEUS AMINOPEPTIDASE

Streptomyces griseus excretes a small molecular mass (30 kDa) aminopeptidase that could be used for various biotechnological applications. This enzyme was isolated from an extracellular protease mixture of Streptomyces griseus (Pronase E, Sigma) and single crystals were obtainedby the vapor diffusion method using polyethylene glycol 4000 as the precipitant. The crystals belong to the tetragonal space group P41212 (P43212), with cell dimensions of a = b = 61·82(3) Å and c = 145·88(4) Å. Thesecrystals are mechanically strong, they are stable in the X-ray beam and they diffract to better than 1·8 Å resolution. The cell dimensions and the cell symmetry are consistent with one molecule in the asymmetric unit and the crystals are suitable for a detailed high-resolution crystallographic analysis. A complete nativedata set to 1·9 Å resolution has been collected on a Rigaku R-AXIS-IIC Imaging Plate Detector system and a heavy-atom derivative search is in progress. © 1993 Academic Press, Inc.