Crystallization and preliminary X-ray investigation at 2.0 A resolution of Bet v 1, a birch pollen protein causing IgE-mediated allergy.

The 17 kDa protein from Betula verrucosa (White Birch) pollen, Bet v 1, is the clinically most important birch pollen allergen causing immediate Type I IgE-mediated allergy. The three-dimensional structure of Bet v 1 and its IgE-binding epitopes are at present not known. In addition, the biological function of Bet v 1 in birch pollen is not fully established. In this work, Bet v 1 has been expressed in Escherichia coli as a recombinant protein, purified and crystallized. The space group of recombinant Bet v 1 crystals is orthorhombic C2221 with unit cell parameters a = 32.13 A, b = 74.22 A, and c = 118.60 A. There is one Bet v 1 molecule per asymmetric unit and the water content is 41%. Crystals diffract to 2.0 A resolution and a complete native data set was collected from a single crystal using CuK alpha X-rays from a rotating anode.