Crystallization and preliminary X-ray analysis of the ATP-binding domain of the ABC transporter haemolysin B from Escherichia coli.

Haemolysin B (HlyB) is a transmembrane protein which belongs to the superfamily of ABC transporters. In vivo, it mediates the non-classical translocation of the 107 kDa toxin HlyA across both membranes of Escherichia coli together with haemolysin D and the outer membrane protein TolC. The cytosolic ATP-binding domain of HlyB has been overexpressed and purified as an N-terminal His-tag fusion protein. Here, the crystallization of the ATPase domain of HlyB in the presence of ATP is described. A native data set has been obtained at a resolution of 2.8 A. Crystals belong to the primitive tetragonal space group P4(x)2(1)2, where x is very likely to be 1 or 3, with unit-cell parameters a = b = 104.6, c = 125.8 A, alpha = beta = gamma = 90 degrees.