Crystallization and preliminary X-ray analysis of the matrix protein of Borna disease virus.

The matrix protein M of Borna disease virus (BDV) is associated with the inner viral membrane and is thought to be a mediator between the nucleocapsid and the lipid-containing envelope in stabilizing the virus shape. The full-length BDV-M gene encoding a 16 kDa protein was expressed in Escherichia coli. M was purified to homogeneity and crystallized by the sitting-drop vapour-diffusion method. The crystals of M belong to the space group I432, with unit-cell parameters a = b = c = 144.6 A, and diffract to 3.1 A.