To test directly if eEF1A could stimulate RNA synthesis by the viral RdRp, we chose the E. coli-expressed recombinant p88 pol RdRp protein of Turnip crinkle virus (TCV), which is unlike the E. coli-expressed TBSV or CNV p92 pol RdRp, does not need the yeast cell-free extract to be functional in vitro [53, 54] . The template specificity of the recombinant TCV RdRp with TBSV RNAs is similar to the closely-related tombusvirus replicase obtained from yeast or infected plants [21, 54, 55, 56] . However, the recombinant TCV RdRp preparation lacks co-purified eEF1A, unlike the yeast or plant-derived tombusvirus replicase preparations, facilitating studies on the role of eEF1A on the template activity of a viral RdRp. When we added the highly purified wt eEF1A to the RdRp assay containing TCV RdRp protein and a TBSV derived (+)RNA template, which is used by the TCV RdRp in vitro to produce the complementary (2)RNA product (Fig. 3A , lanes 3-4) [55] , we observed a ,6-fold increase in (2)RNA synthesis by the TCV RdRp (lanes 11-12), while, as expected, we did not detect new (+)RNA progeny (not shown). This suggests that eEF1A can greatly stimulate TCV RdRp activity in vitro, confirming a direct role for eEF1A in (2)RNA synthesis by a viral RdRp.