Viruses and geometry – a new
perspective on virus assembly and anti-viral therapy
Reidun Twarock, NYU
A large number of
human, animal and plant viruses make use of protein containers,
called viral capsids, to encapsulate and hence provide
protection for their genomes. In many cases, these viral capsids
exhibit symmetry, and they can therefore be modelled using
techniques from group, graph and tiling theory. It has
previously been assumed that their formation from the
constituent protein building blocks can be fully understood as a
self-assembly process in which viral genomes are only passive
passengers. Our mathematical approach, in concert with
techniques from bioinformatics, biophysics and experiment,
provides a new perspective. It shows that, by contrast,
interactions between viral genome and capsid play vital
cooperative roles in this process in the case of RNA viruses,
enhancing assembly efficiency and fidelity. We use the graph
theoretical concept of Hamiltonian path to quantify the
resulting complexity reduction in the number of assembly
pathways, and discuss implications of these insights for a novel
form of anti-viral therapy.