Fig. 4.
F occurs in two different conformations on the virions. Averages of class 1 (253 subvolumes) representing the long (A) and class 2 (226 subvolumes) representing the short spike (B) from subvolumes extracted from both A2 and rgΔGΔSH virions. Class averages 1 (224 subvolumes) and 2 (65 subvolumes) including only subvolumes from rgΔGΔSH are shown (C and D). Positions of the classified spikes on the A2 virions (E and F) and on the rgΔGΔSH virions (G and H). Tomographic slices in E–H are transparent to show all spike positions. Cyan spheres correspond to class 1 spikes and magenta spheres to class 2 spikes. (A–D) Scale bar in (C) is 10 nm. (E–H) Scale bar in (E) is 100 nm.