The identified eEF1A mutants were also useful to dissect the functions of eEF1A in TBSV replication. Based on a cell-free TBSV replication assay in CFE prepared from yeast expressing the C42, C53 or C62 mutants, we found that the minus-strand synthesis was enhanced by ,3-fold, while the rate of plus-strand synthesis was proportionate with (2)RNA synthesis, resulting in ,10-fold more (+) than (2)RNA products for wt and each mutant.