Density waves theory of the capsid structure of small icosahedral viruses

TL;DR

This paper applies Landau crystallization theory to classify and predict the structure of small icosahedral virus capsids, unifying different structural models with a universal density distribution.

Contribution

It introduces an explicit, parameter-free method to predict protein positions in viral capsids, bridging classical geometrical models and deviations from them.

Findings

Predicts protein positions without fitting parameters

Unifies Caspar-Klug and non-conforming capsid structures

Discusses thermodynamics of viral assembly

Abstract

We apply Landau theory of crystallization to explain and to classify the capsid structures of small viruses with spherical topology and icosahedral symmetry. We develop an explicit method which predicts the positions of centers of mass for the proteins constituting viral capsid shell. Corresponding density distribution function which generates the positions has universal form without any fitting parameter. The theory describes in a uniform way both the structures satisfying the well-known Caspar and Klug geometrical model for capsid construction and those violating it. The quasiequivalence of protein environments in viral capsid and peculiarities of the assembly thermodynamics are also discussed.