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

Abstract

ZBP1 is involved in host responses against cellular stresses, including tumorigenesis and viral infection. Structurally, it harbors two copies of the Zα domain containing the Zα motif, at its N terminus. Here, we attempted to characterize the Z-DNA binding activities of two Zα domains in the human ZBP1, hZαZBP1 and hZβZBP1, using circular dichroism (CD). Our results indicated that both hZα ZBP1 and hZβZBP1 are viable Z-DNA binders, and their binding activities are comparable to those of previously-established Zα domains. Additionally, we crystallized hZβZBP1 in a complex with Z-DNA, d(TCGCGCG)2. The crystal diffracted to 1.45 ?, and belongs to the P212121 space group, with the unit-cell parameters: a = 29.53 ?, b = 58.25 ?, and c = 88.61 ?. The delineation of this structure will provide insight into the manner in which diverse Zα motifs recognize Z-DNA.