Figure 6.

AFM images of a single collapsed MVM capsid. (A) Before indentation, the intact capsid is oriented with an S2 axis on top; in the 3D image, the capsomers around this axis are numbered. (B) After indentation, the capsid is completely flattened. Counting of capsomers reveals that only 4 or 5 of the 20 capsomers are missing; in the 3D image, the capsomers around each of four S5 axes observed are numbered 1–4. (C) Height profiles of the capsid before (solid line) and after (dashed and dotted lines) collapse. (D) A 2D-extended icosahedral model with the faces of the icosahedron labeled according to the code used for the equivalent capsomers in B. Black arrows connect intercapsomer interfaces that are not formed in the model but appear to be still formed in the collapsed capsid. The four missing capsomers (m) in the collapsed capsid are labeled. Some capsomers or pentamers of capsomers in B may be not attached (D) but just lying next to each other. Possibly disconnected interfaces are indicated by a yellow dashed line in the model.