Crystallization and preliminary X-ray data investigation of the bacterial enterocin A immunity protein at 1.65 A resolution.

Crystals of the bacterial enterocin A immunity protein have been prepared by the hanging-drop vapour-diffusion technique at 293 K. The crystals diffract to better than 1.7 A resolution and X-ray diffraction data to 1.65 A have been collected at 110 K using synchrotron radiation. The enterocin A immunity protein crystals belong to the monoclinic crystal system, with unit-cell parameters a = 116.32, b = 42.35, c = 66.17 A, beta = 111.3 degrees. The symmetry and systematic absences in the diffraction pattern are consistent with space group C2. The presence of two molecules in the asymmetric unit with a molecular weight of approximately 12.2 kDa gives a crystal volume per protein mass (V(M)) of approximately 3.1 A(3) Da(-1) and a solvent content of approximately 60% by volume.