Fig. 4: Cryo-EM analysis of hemagglutinin (HA) trimer.

a Local resolution of HA trimer in two different views, as estimated by cryoSPARC and shown with pseudo-color representation of resolution. b dFSC from different Fourier cones for HA with or without MSBP. Each curve indicates a different direction. c Angular distribution of reconstructed catalase (left) and β-galactosidase (right) with (top) or without (bottom) MSBP. d Statistics of HA trimer particles in three different views. Obviously, top views are the preferred orientation of HA trimer without MSBP. The proportions of the side views and tilted views of HA trimer with MSBP increased significantly.