The synergistic effect of these host proteins could promote efficient recycling of the viral RdRp resulting in multiple rounds of (+)RNA synthesis ( Figure 9 ). Thus, the roles of these host proteins are to serve as ''matchmakers'' between the viral RNA template and the viral RdRp. It is intriguing that two host proteins, eEF1A and eEF1Bc, are proposed to serve somewhat similar functions during (2)RNA initiation for TBSV [27, 29] . Therefore, the emerging picture is that TBSV utilizes different host proteins for promoting (2) versus (+)RNA synthesis. This strategy could be beneficial for the virus by allowing asymmetric RNA synthesis, thus leading to excess amount of progeny (+)RNA.