The TCV RdRp reactions were carried out as previously described for 2 h at 25uC [54] . Briefly, the RdRp reactions were performed in a 20 ml reaction containing 50 mM Tris-HCl (pH 8.2), 10 mM MgCl 2 , 10 mM DTT, 1.0 mM each ATP, CTP, and GTP, 0.01 mM UTP plus 0.1 ml of [ 32 P]UTP, 7 pmol template RNA, 2 pmol affinity-purified MBP-p88C. 20 pmol eEF1A was added to the reaction at the beginning or as indicated in the text and Fig. 3 legend. The 32 P-labeled RNA products were analyzed by electrophoresis in a 5% or 15% PAGE/8 M urea gel [57] . The 86-nt 39 noncoding region of TBSV genomic RNA was used as the template in the RdRp assay [25, 54] .