Fig. 2.

TBSV p33/p92-mediated binding of TBSV RNA to artificial vesicles containing different phospholipids. (A) Scheme of the in vitro binding assay and membrane-flotation experiments. The ³²P-labeled TBSV (+)repRNA (DI-72) was incubated with artificial vesicles in the presence of purified recombinant TBSV p33 and p92 (plus the S40 fraction of yeast CFE to provide soluble cellular factors, such as heat shock protein 70), followed by centrifugation in 10–70% sucrose density gradient. The top fraction of the sucrose gradient was tested for the presence of ³²P-labeled TBSV (+)repRNA. (B) Denaturing RNA gel analysis of the presence of ³²P-labeled TBSV (+)repRNA in the top fraction. The amount of ³²P-labeled TBSV (+)repRNA with the PE vesicles was chosen as 100%.