(268a) Thermodynamic and Kinetic Constraints On Viral Packaging [Invited]

During the replication of many viruses, hundreds to thousands of protein subunits assemble around the viral nucleic acid to form a protein shell called a capsid.  Capsid formation is a multicomponent, out-of-equilibrium assembly process for which kinetic effects and thermodynamic constraints compete to determine the outcome. Success or failure hinges crucially on the interactions among the assembling components, and most viruses have evolved their structural components to drive highly efficient assembly. In this presentation, we will describe computer simulations that represent the assembly of a capsid around a nucleic acid or a synthetic polyelectrolyte. We will investigate how the length of nucleic acid which can be packaged during a dynamical assembly process depends on solution conditions. We will then compare the results to equilibrium calculations to determine the extent to which kinetics or if thermodynamics is a limiting factor. Finally, we will describe how one virus may be assembling a metastable complex primed for release of its nucleic acid cargo.