Yeast strains (WT, C42, C53, C62) were transformed with plasmids pESCHIS4-ADH-HF33/CUP1-DI-72 expressing 6XHis-and Flag-tagged CNV p33 and the TBSV DI-72 repRNA, and pRS317-Tet-His92, expressing CNV p92 under the control of Tet promoter [25] . Co-purification was done according to a previously described procedure with the following modification [25] . Gel mobility shift assay (EMSA) and co-purification of eEF1A-repRNA EMSA was performed in a 10 ml-reaction containing 20 mM HEPES [pH 7.6], 50 mM KCl, 2 mM MgCl 2 , 1 mM DTT, 0.1 mM EDTA, 10% [vol/vol] glycerol, 10 U of RNase inhibitor, 10 nM 32 P-labeled DI-72 (+) RNA probe and 0.5 mg purified eEF1A protein [76] . Reactions were incubated at room temperature for 20 min and then resolved by 4% nondenaturing polyacrylamide gel as described previously [25] .