Rinderpest virus RNA polymerase subunits: Mapping of mutual interacting domains on the Large protein L and Phosphoprotein P

The RNA dependant RNA polymerase of negative sense RNA viruses is composed of two subunits - the Large protein ( L) and the Phosphoprotein ( P). These two proteins have to form a complex in order to carry out genome transcription and replication. Employing the baculovirus expression system, we demonstrate here, the specific in vivo interaction between the L and P proteins of Rinderpest virus and also the stabilization of L protein when it is present as L+P complex. The regions on either protein involved in such interaction has been studied using the yeast two-hybrid system which indicates that the P binding region resides within the amino terminal 380 amino acid residues of L protein. The L binding region on P protein has been mapped to lie within 347 - 490 amino acids.