A minimal representation of the self-assembly of virus capsids

Abstract

Viruses are biological nanosystems with a capsid of protein-made capsomer units that encloses and protects the genetic material responsible for their replication. Here we show how the geometrical constraints of the capsomer-capsomer interaction in icosahedral capsids fix the form of the shortest and universal truncated multipolar expansion of the two-body interaction between capsomers. The structures of many of the icosahedral and related virus capsids are located as single lowest energy states of this potential energy surface. Our approach unveils relevant features of the natural design of the capsids and can be of interest in fields of nanoscience and nanotechnology where similar hollow convex structures are relevant.

The role of the encapsulated cargo in microcompartment assembly

“…We observe that the degree of icosahedral symmetry increases with shell size, and is correlated to the assembly pathway. Small shells that assemble by one-step pathways (with ∼ 50 subunits) are clearly asymmetric, corresponding neither to icosahedral symmetry nor other symmetric lowenergy minimum arrangements expected for shells in this size range [95], whereas large shells are nearly (though not perfectly) icosahedral. The lack of perfect symmetry likely arises because the hexamers form an elastic sheet, within which shell reorganization and defect diffusion are slow in comparison to assembly timescales.…”

Acquiring Structural Information on Virus Particles with Charge Detection Mass Spectrometry

“…Such a large fraction of these variant PCs misassemble into nonspecific structures because of the non-ideal curvature induced by the substituted residue. Icosahedral capsids are expected to be more stable than nonspecific ones [61–63]. The PCs that manage to correctly form icosahedral capsids are probably stable enough to maintain their hollow structure in the gas phase, but the malformed, incomplete particles that do not have the proper symmetry or intra-capsid interactions probably partially collapse during their transition into the gas phase.…”

Wall mechanics and exocytosis define the shape of growth domains in fission yeast

“…The regular self-assembly of viruses from protein subunits offers an interesting paradigm for how shape can be encoded at the molecular level 1 2 3 . However, most cells are of a scale that lies above the reach of molecular self-assembly and as a consequence their shape results from a subtle interplay between biochemical regulation and mechanical constraints 2 4 5 6 7 .…”