Rinderpest virus C and V proteins interact with the major (L) component of the viral polymerase.

Rinderpest virus, like other Morbilliviruses, expresses three proteins from the single P gene. In addition to the P protein, which interacts both with the viral polymerase (L) and the nucleocapsid (N) protein, the virus expresses a C and a V protein from the same gene. The functions of these two proteins in the viral life cycle are not clear. Although both C and V proteins are dispensable, in that viable viruses can be made that express neither, each seems to play a role in optimum viral replication. We have used the yeast-two hybrid system, binding to coexpressed fusions of C and V to glutathione-S-transferase, and studies of the native size of these proteins to investigate interactions of the rinderpest virus C and V proteins with other virus-encoded proteins. The V protein was found to interact with both the N and L proteins, while the C protein was found to bind to the L protein, and to self-associate in high-molecular-weight aggregates.