CRYSTALLIZATION AND PRELIMINARY-X-RAY CRYSTALLOGRAPHIC ANALYSIS OF IMME7 PROTEIN OF COLICIN E7

The ImmE7 protein, which can bind specifically to the DNase colicin E7 and neutralize its bactericidal activity, has been pu. rifled and cry stallized in two different crystal forms by vapor diffusion method, Th e orthorhombic crystals belong to space group I222 or I2(1)2(1)2(1) an d have unit cell dimensions a = 75.1 Angstrom, b = 50.5 Angstrom, and c = 45.4 Angstrom. The second form is monoclinic space group P2(1) wit h cell dimensions a = 29.3 Angstrom, b = 102.7 Angstrom, c = 53.0 Angs trom, and beta = 91.5 degrees. The orthorhombic crystals diffract to 1 .8 Angstrom resolution, and are suitable for high-resolution X-ray ana lysis. (C) 1995 Wiley-Liss, Inc.