CRYSTALLIZATION AND PRELIMINARY-X-RAY CRYSTALLOGRAPHIC ANALYSIS OF THE SOYBEAN PROGLYCININ EXPRESSED IN ESCHERICHIA-COLI

Glycinin is one of the dominant storage proteins of soybean seeds. Soybean proglycinin expressed in Escherichia coli has been crystallized from Tris·HCl buffer (pH 7.6) by the dialysis equilibrium method. The crystals belong to the tetragonal system, space group P41 or P43, with unit cell dimensions of a=b=115.2 Å, and c=147.1 Å. The asymmetric unit contains three molecules of proglycinin, with crystal volume per protein mass (Vm) of 3.05 Å3/Da and solvent content of 58.4% by volume. The crystals diffract X-rays to a resolution limit of at least 2.9 Å and are resistant to X-ray radiation damage. They appear to be suitable for X-ray structure analysis. © 1993 Academic Press Limited.