Biochemical characterization and preliminary study of the domains of human ZBP1 bound X-ray crystallographic to left-handed Z-DNA

ZBP1 is involved in host responses against cellular stresses, including tumorigenesis and viral infection. Structurally, it harbors two copies of the Z alpha domain containing the Za motif, at its N terminus. Here, we attempted to characterize the Z-DNA binding activities of two Z alpha domains in the human ZBP1, hZ alpha(ZBP1) and hZ beta(ZBP1), using circular dichroism (CD). Our results indicated that both hZ alpha(ZBP1) and hZ beta(ZBP1) are viable Z-DNA binders, and their binding activities are comparable to those of previously-established Za domains. Additionally, we crystallized hZ beta(ZBP1) in a complex with Z-DNA, d(TCGCGCG)(2). The crystal diffracted to 1.45 angstrom, and belongs to the P2(1)2(1)2(1) space group, with the unit-cell parameters: a=29.53 angstrom, b=58.25 angstrom, and c=88.61 angstrom. The delineation of this structure will provide insight into the manner in which diverse Za motifs recognize Z-DNA. (c) 2005 Elsevier B.V. All rights reserved.