  Understanding the pathways by which viral capsid proteins assemble around
their genomes could identify key intermediates as potential drug targets. In
this work we use computer simulations to characterize assembly over a wide
range of capsid protein-protein interaction strengths and solution ionic
strengths. We find that assembly pathways can be categorized into two classes,
in which intermediates are either predominantly ordered or disordered. Our
results suggest that estimating the protein-protein and the protein-genome
binding affinities may be sufficient to predict which pathway occurs.
Furthermore, the calculated phase diagrams suggest that knowledge of the
dominant assembly pathway and its relationship to control parameters could
identify optimal strategies to thwart or redirect assembly to block infection.
Finally, analysis of simulation trajectories suggests that the two classes of
assembly pathways can be distinguished in single molecule fluorescence
correlation spectroscopy or bulk time resolved small angle x-ray scattering
experiments.
