No abstract

Deletion and substitution mutations affecting the oligomerization of alfalfa mosaic virus (AMV) coat protein (CP) were studied in protoplasts to determine their effect on genome activation, an early step in AMV replication. The CP mutants that formed dimers, CPDeltaC9 and CPC-A(R)F, were highly active in initiating replication with 63-84% of wild-type (wt) CP activity. However, all mutants that did not form dimers, CPDeltaC18, CPDeltaC19, CPC-WFP, and CPC-W, were much less active with 19-33% of wt CP activity. The accumulation and solubility of mutant CPs expressed from a virus-based vector in Nicotiana benthamiana were similar to that of wt CP. Analysis of CP-RNA interactions indicated that CP dimers and CP monomers interacted very differently with AMV RNA 3' ends. These results suggest that CP dimers are more efficient for replication than CP monomers because of differences in RNA binding rather than differences in expression and accumulation of the mutant CPs in infected cells.

Biomolecules are increasingly attractive templates for the synthesis of functional nanomaterials. Chief among them are the plant Tobacco mosaic virus (TMV) and Barley stripe mosaic virus (BSMV) due to their high aspect ratio, narrow size distribution, diverse biochemical functionalities presented on the surface, and compatibility with a number of chemical conjugations. These properties are also easily manipulated by genetic modification to enable the synthesis of a range of metallic and non-metallic nanomaterials for diverse applications. This article reviews the characteristics of TMV, BSMV, and their virus-like particle (VLP) derivatives and how these may be manipulated to extend their use and function. A focus of recent efforts has been on greater understanding and control of the self-assembly processes that drive biotemplate formation. We briefly outline how these features have been exploited in engineering applications such as sensing, catalysis, and energy storage, and discuss emerging advances that promise to accelerate the development of these biotemplates for widescale industrial use.