To obtain additional evidence if eEF1Bc could stimulate RNA synthesis by the viral RdRp, we used the E. coli-expressed recombinant p88C pol RdRp protein of Turnip crinkle virus (TCV). The TCV RdRp, unlike the E. coli-expressed TBSV p92 pol or the closely-related Cucumber necrosis virus (CNV) p92 pol RdRps, does not need the yeast CFE to be functional in vitro [35, 36] . Importantly, the template specificity of the recombinant TCV RdRp with TBSV RNAs is similar to the closely-related tombusvirus replicase purified from yeast or infected plants [10, 36, 37, 38] . The recombinant TCV RdRp preparation lacks co-purified eEF1Bc (E. coli does not have a homolog), unlike the yeast or plant-derived tombusvirus replicase preparations, facilitating studies on the role of eEF1Bc on the template activity of a viral RdRp. When we added various amounts of the highly purified recombinant eEF1Bc to the TCV RdRp assay programmed with TBSVderived SL3-2-1(+) RNA template, which is used by the TCV RdRp in vitro to produce the complementary (-)RNA product [37] , we observed a ,2-to-4-fold increase in (-)RNA synthesis by the TCV RdRp (Figure 2A , lanes [3] [4] [5] . eEF1Bc in the absence of the TCV RdRp did not give a 32 P-labeled RNA product, excluding that our eEF1Bc preparation contained RdRp activity (not shown). Altogether, our data suggest that eEF1Bc can stimulate in vitro activity of TCV RdRp on a TBSV (+)RNA template, confirming a direct role for eEF1Bc in viral (-)RNA synthesis by a viral RdRp.