The highly purified tombusvirus VRC is known to contain at least six permanent resident host proteins, including the heat shock protein 70 chaperones (Hsp70, Ssa1/2p in yeast) [21] [22] [23] [24] , glyceraldehyde-3-phosphate dehydrogenase (GAPDH, encoded by TDH2 and TDH3 in yeast) [25] , pyruvate decarboxylase (Pdc1p) [24] , Cdc34p E2 ubiquitin conjugating enzyme [24] [25] [26] , eukaryotic translation elongation factor 1A (eEF1A) [27, 28] , eukaryotic translation elongation factor 1Bgamma (eEF1Bc) [29] and two temporary resident proteins, Pex19p shuttle protein [30] and the Vps23p adaptor ESCRT protein [28, 31, 32] . Although the functions of several of these proteins have been studied in some details, additional host proteins might be also present in tombusvirus VRC [5, 10, [21] [22] [23] 25] . One of the intriguing questions is if tombusviruses use host-coded helicases for their replication. This is because, unlike larger RNA viruses, the tombusvirus genome does not code for a protein with helicase function. Thus, can tombusviruses and other small RNA viruses replicate without the use of a helicase or they subvert a cellular helicase(s) to assist their replication? DEAD-box proteins constitute the largest family of RNA helicases that are involved in all aspects of cellular metabolism and perform RNA duplex unwinding and remodeling of RNA-protein complexes in cells [33] [34] [35] . Ded1p, which is essential for yeast growth, is among the best-characterized DEAD-box helicases [36] . It is involved in initiation of translation of every yeast mRNA [37] [38] [39] and down-regulation of Ded1p level also reduced p33 and p92 levels in yeast [20] . Therefore, not surprisingly, TBSV replication also decreased significantly in yeast with reduced level of Ded1p. Due to its essential role in translation, it is critical to separate the possible role of Ded1p in viral replication from its effect on viral translation.