Figure 1.

Structure of NSP14 in the absence of NSP10. (A) Overall NSP14 structure with the ExoN domain colored yellow, hinge domain in green and MTase domain slate, zinc ions are shown as blue-grey spheres and phosphate ions are shown in ball and stick format. (B) Close up view of the ExoN domain with regions that were observed to shift conformation highlighted in ‘sand’ color. (C) Structure of the ExoN domain of SARS-CoV NSP14 in complex with NSP10 (shown in pink) viewed from the same orientation as for panel B. (D) The interaction between NSP14 and NSP10 has been described as ‘hand over fist’, by the same logic the ‘fingers’ of NSP14 collapse back toward the core resembling a closed ‘fist’.