Cloning, purification and crystallization of full-length human annexin 2

Annexin 2, a Ca2+/phospholipid-binding protein, is involved in many biological processes, including membrane aggregation and the modulation of fibrinolytic activity. Here, the expression and purification of recombinant full-length human annexin 2 is reported, as well as crystals obtained by sitting-drop and hanging-drop vapor diffusion at 277 K. A condition consisting of 18% PEG 8000, 0.1 M sodium cacodylate pH 6.5, 0.2 M calcium acetate yielded long needles that diffracted to 3.20 Angstrom. Another condition, consisting of 2.5 M NaCl, 0.1 M acetate pH 4.5, 0.2 M Li2SO4, gave crystals with unit-cell parameters a = 48.36, b = 62.86, c = 119.11 Angstrom that diffracted to 1.52 Angstrom. Both crystals belong to the orthorhombic P2(1)2(1)2(1) space group. The high-resolution 1.52 A E data set was collected at ALS beamline 5.0.2 and is 93.0% complete, with an R-sym of 4.5%. The structure of full-length annexin 2 will provide insight into how its N-terminal domain contributes to its functional role in a variety of biological processes.