[Effect of structural P-protein of potato curly dwarf virus on replicase activity of mRNP-complexes of infected plants].

All representatives of rhabdoviruses contain a nucleocapside phosphoprotein - P-protein which is an essential subunit of the viral RNA-dependent RNA polymerase complex. As a result of studying the effect of nucleocapside protein P(NS) on replicase activity of mRNP isolated from plants infected by potato curly dwarf virus in the system in vitro, it was established that nucleocapside P-protein stimulates considerably the replicase activity of membrane-bound polysomal m-RNP P-protein being available in concentration of 15 microg/ml in the replication system in vitro of membrane-bound polysomal mRNP, the replicase activity increased 11.7 times. This property of nucleocapside P-protein at the same concentration was displayed to a less extent with the presence of free polysomal mRNP, in the system in vitro. Thus the replicase activity mRNP-complexes in the replication system in vitro depends on the presence of nucleocapside viral P-protein in the system. Its concentration being increased or decreased, one can observe the change of the replicase activity.