Fig. 6.

Mapping of the Arbidol-resistance mutations on HA. The crystal structure of Arbidol in complex with H7N9 A/Shanghai/2/2013 (H7/SH2) HA is represented with the HA shown as a transparent gray surface. The HA2 is also shown in gray secondary structure backbone traces, and Arbidol is shown as yellow sticks. One of the three N-terminal fusion peptides in the trimer has been highlighted as a red ribbon, and its N terminus is labeled “N.” Previously reported Arbidol-resistance mutations K51N, K117R, Q42H, and Q27N in HA2 are shown as green spheres, and the previously predicted binding site for Arbidol from docking studies is marked by a blue dashed circle.