Cell-fractionation assay, followed by the cell-free TBSV replication assay demonstrated that the soluble fraction from the C42, C53 and C62 mutant yeasts stimulated the in vitro replication of TBSV repRNA by ,3-fold, while the membrane fraction when derived from C42, C53 and C62 mutant yeasts had a lesser effect (Fig. 2D , lanes 12-14 versus 7-9). These data are in agreement with the expected mostly cytosolic distribution of eEF1A, albeit eEF1A is also present in the membrane fraction in a smaller amount (Fig. 2D , bottom panel).