In vitro evidence for RNA binding properties of the coat protein of prunusnecrotic ringspot ilarvirus and their comparison to related and unrelated viruses

The RNA binding properties of the prunus necrotic ringspot virus (PNRSV) co at protein (CP) were demonstrated by northwestern and dot-blot analyses. Th e capability to bind PNRSV RNA 4 was compared with viruses representing thr ee different interactions prevailing in the assembly and architecture of vi rions. The results showed that cucumber mosaic virus (CMV) and PNRSV CPs, w hich stabilise their virions mainly through RNA-protein interactions bound PNRSV RNA 4 even at very high salt concentrations. The CP of cherry leaf ro ll nepovirus, whose virions are predominantly stabilised by protein-protein interactions did not bind even at the lowest salt concentration tested. Fi nally the CP of carnation mottle carmovirus, that has an intermediate posit ion in which both RNA-protein and protein-protein interactions are equally important showed a salt-dependent RNA binding.