Various proteomics analyses of the highly purified tombusvirus replicase has revealed at least five permanent resident host proteins in the complex, including the heat shock protein 70 chaperones (Hsp70) [18] [19] [20] [21] , glyceraldehyde-3-phosphate dehydrogenase [4] , pyruvate decarboxylase [21] , Cdc34p E2 ubiquitin conjugating enzyme [4, 21, 22] , eukaryotic translation elongation factor 1A (eEF1A) [23, 24] and two temporary resident proteins, Pex19p shuttle protein [25] and the Vps23p adaptor ESCRT protein [24, 26, 27] . The functions of several of these proteins have been studied in some detail [4, 17, 18, 19, 20] .