Initiation factor eIF3 has been shown to crosslink to the FCV TURBS [17] . More important, supplementary eIF3 has been shown to stimulate reinitiation at the wild-type FCV TURBS, but more especially at TURBS derivatives which are partially defective due to deletions or point mutations [17] , just as has been observed here (Figure 7) . These results, particularly the stimulation of the partially defective TURBS, have suggested a model in which it is specifically the eIF3 associated with the TURBS that binds those 40S subunits which are destined to reinitiate translation [17] . There is no conflict between this hypothesis and the model in which tethering the 40S subunit to the TURBS is due to base-pairing between TURBS motif 1 and 18S rRNA. eIF3 binds predominantly to the back or solvent face of the 40S ribosomal subunit, and is known to make direct contacts with the 18S rRNA component of the small ribosomal subunit [39, 40] . A bridging interaction in which eIF3 binds simultaneously to the 40S subunit and to the TURBS could help stabilise the binding of the 40S subunit to the TURBS for sufficient time as is required to acquire an eIF2/GTP/Met-tRNA i ternary complex, and other necessary initiation factors. After all, the analogous Shine-Dalgarno interaction of prokaryotic 30S subunits is generally considered to be very transitory unless it is accompanied and stabilised by a P-site fMet-tRNA base-pairing with an AUG (or GUG) at an appropriate distance further downstream.