9507344 Kao Viruses with genomes of (+)-stranded RNAs make up a diverse group that include economically important pathogens of animals and plants. The mechanism of replication of these RNA genomes is not understood well, and what roles host proteins play are just beginning to be determined. The overall goal of this research is to understand the mechanism by which the model (+)-strand RNA virus, brome mosaic virus (BMV), replicates its genome. Experiments will focus on two key areas, the identification and characterization of host factors involved in viral RNA replication, and the interaction of viral proteins within the RNA-dependent RNA polymerase. The anticipated results are important because they will elucidate fundamental aspects of viral RNA replication, including the role of host proteins and the interaction of viral proteins. Many, if not all, of these mechanistic details should prove to be common among viral pathogens with (+)-strand RNA genomes. Advances in our understanding of RNA replication will provide the basis for the development of new strategies for the inhibition of viral infection. %%% Viruses with genomes of (+)-stranded RNAs make up a diverse group that include economically important pathogens of animals and plants. The mechanism of replication of these RNA genomes is not understood well, and what roles host proteins play are just beginning to be determined. The overall goal of this research is to understand the mechanism by which the model (+)-strand RNA virus, brome mosaic virus (BMV), replicates its genome. The anticipated results are important because they will elucidate fundamental aspects of viral RNA replication, including the role of host proteins and the interaction of viral proteins. Many, if not all, of these mechanistic details should prove to be common among viral pathogens with (+)-strand RNA genomes. Advances in our understanding of RNA replication will provide the basis for the development of new strategies for the inhibition of viral infection. ***