Brome mosaic virus capsid protein regulates accumulation of viral replication proteins by binding to the replicase assembly RNA element

Coexpression of BMV 2a protein can rescue BMV RNA accumulation. Agrobacterium cultures expressing three genomic RNAs were either infiltrated into N. banthamiana plants along with a culture harboring pCP (at OD₅₉₅ of 1.0) or infiltrated with culture expressing pCP along with increasing concentrations of a culture that can express the 2a protein. Viral RNAs were detected by Northern blot assay. The levels of RNA3 and RNA4 were quantified and shown below the cellular RNA (cRNA) loading control. Amounts of RNA3 and RNA4 were determined by Phosphorimage analysis and normalized to the sample lacking cultures expressing both pCP and p2a.