Crystallization and preliminary X-ray studies of cyclodextrin glucanotransferase from alkalophilic Bacillus sp. 1011

Large crystals of cyclodextrin glucanotransferase (CGTase) from alkalophilic Bacillus sp. 1011, a typical alkalophilic enzyme, have been obtained at room temperature using polyethylene glycol 3000 and 2-propanol as precipitant. They belong to the triclinic space group P1 with the following unit cell constants: a = 64.93 A, b = 74.45 A, c = 79.12 A, alpha = 85.2 degrees, beta = 105.0 degrees and gamma = 101.0 degrees. The crystallographic asymmetric unit seems to contain two molecules of CGTase, with crystal volume per protein mass (Vm) of 2.41 A3/Da and solvent content of 49% by volume. The crystals diffract to at least 2.0 A resolution and they are suitable for X-ray analysis.