FIG. 7.

EM of unpurified CLPs formed by VP7 mutants. Sf cells were coinfected with Ac17BTV-3 and one of the mutant viruses expressing either R111F, T321R, or W1119D. The infected-cell lysates were loaded onto a discontinuous sucrose step gradient (66% [wt/wt]) and 40% [wt/vol]) in 200 mM Tris-HCl (pH 8.0)–150 mM NaCl and centrifuged for 3 h on an SW28 rotor at 26,000 rpm. The interface above the 66% sucrose was collected and visualized by EM as described in Materials and Methods.