Potato virus X (PVX) and some other potexviruses can be reconstitutedin vitrofrom viral coat protein (CP) and RNA. PVX CP is capable of forming viral ribonucleoprotein complexes (vRNP) not only with homologous, but also with foreign RNAs. This paper presents the structure and properties of vRNP assembledin vitroupon incubation of PVX CP and RNAs of various plant and animal viruses belonging to different taxonomic groups. We have shown that the morphology and translational properties of vRNPs containing foreign (heterologous) RNA are identical to those of homological vRNP (PVX RNA - PVX CP). Our data suggest that the assembly of the "mixed" vRNPin vitrocould be started at the 5'-proximal region of the RNA, producing a helical structure of vRNPs with foreign nucleic acids. The formation of heterologous vRNPin vitrowith PVX CP appears not to require a specific 5' end RNA nucleotide sequence, and the PVX CP seems to be able to pack foreign genetic material of various sizes and compositions into artificial virus-like particles.
Keywords: RNA; plant viruses; translation activation; viral ribonucleoproteins.