Structural basis for the regulatory function of a complex zinc-binding domain in a replicative arterivirus helicase resembling a nonsense-mediated mRNA decay helicase

Deng, Zengqin; Lehmann, Kathleen C.; Li, Xiaorong; Feng, Chong; Wang, Guoqiang; Zhang, Qi; Qi, Xiaoxuan; Yu, Lin; Zhang, Xingliang; Feng, Wenhai; Wu, Wei; Gong, Peng; Tao, Ye; Posthuma, Clara C.; Snijder, Eric J.; Gorbalenya, Alexander E.; Chen, Zhongzhou

Like the protein-binding surface of the Upf1 C/H domain (54) , ZBD has a putative protein interaction surface composed of two major hydrophobic zones that are almost perpendicular to each other ( Figure 8 ). Nucleic acid binding induced a conformational change (Supplementary Figure S6B ) of these two zones. In addition, the temperature factor of the treble-clef zinc finger was higher and several residues are disordered in the structure of the nsp10Á-DNA complex (Supplementary Figure S2 ). Together, these findings imply that these two zones are readily accessible for interactions with other proteins, which may further influence nucleic acid binding.