Fig. 8.

Substitution with polar residues at position 54 of ORF65 abolished capsid self-assembly. (a) Examination of infected cells using conventional thin-section TEM revealed the presence of aberrant structures (arrows) in cells infected with viruses expressing ORF65 L49K or I53K plus all the viruses expressing the five other capsid proteins. No capsid structures or shells were evident in cells infected with virus expressing ORF65 A54K, whereas closed capsid structures (arrowhead) were observed in cells infected with the virus expressing ORF65 WT protein. Bars, 500 nm. (b) ORF65 polypeptides containing substitution of residue 54 with L, V, P and K were tested for self-assembly as judged by sucrose gradient sedimentation of infected cell lysates. The arrow indicates direction of sedimentation. (c) Stable accumulation of ORF65 polypeptides tagged with HA was observed in infected cell lysates using immunoblot methods and anti-HA (αHA) antisera. Proteins standards (kDa) are shown in lane M.