Recombinant L and P protein complex of Rinderpest virus catalyses mRNA synthesis in vitro

Rinderpest virus belongs to the family of Paramyxoviridae, consisting of non-segmented negative sense RNA viruses. Viral transcription and replication are carried out by the RNA dependent RNA polymerase L protein which functions together with P protein as L–P complex. The exact events triggering the polymerase complex from transcription to replication function is poorly understood. In the present work, an in vitro transcription system has been described with partially purified L–P complex expressed in insect cells and viral genomic RNA. The relative abundance of each species of mRNA synthesized in vitro decreased from the 3′ end of the genome to the 5′ end similar to their abundance in virus infected cells. Recombinant L–P complex was unable to synthesize leader RNA suggesting the initiation of transcription from gene start site and not at the 3′ end of the genome.