Crystallization and preliminary X-ray diffraction data of the complex of recombinant tick anticoagulant peptide (rTAP) and bovine factor Xa

The complex of bovine factor Xa and recombinant tick anticoagulant peptide (rTAP) was crystallized in two different crystal forms using polyethylene g lycol as a precipitant. Form I belongs to space group P4(2)2(1)2 with unit- cell dimensions a = b = 133.1, c = 68.5 Angstrom. It contains one complex p er asymmetric unit and diffracts to 3.0 Angstrom resolution. Form II belong s to P4(1)2(1)2 (or P4(3)2(1)2) With dimensions a = b = 126.5, c = 146.7 An gstrom; it contains two complexes per asymmetric unit and diffracts to 2.5 Angstrom. The crystals of both forms consist of factor Xa (M-W = 45.3 kDa) and rTAP (M-W = 6.7 kDa).