Genome packaging within icosahedral capsids and large-scale segmentation in viral genomic sequences

TL;DR

This study uses Fourier analysis to reveal quasi-regular segmentation in viral genomes that correlates with icosahedral capsid assembly, providing insights into hierarchical genome packaging and potential antiviral targets.

Contribution

It introduces a Fourier transform-based method to analyze viral genomic segmentation related to capsid assembly, linking sequence patterns with structural data.

Findings

Detected significant quasi-regular segmentation in viral genomes.

Found correspondence between sequence segmentation and capsid structure.

Provided insights into hierarchical genome packaging mechanisms.

Abstract

The assembly and maturation of viruses with icosahedral capsids must be coordinated with icosahedral symmetry. The icosahedral symmetry imposes also the restrictions on the cooperative specific interactions between genomic RNA/DNA and coat proteins that should be reflected in quasi-regular segmentation of viral genomic sequences. Combining discrete direct and double Fourier transforms, we studied the quasi-regular large-scale segmentation in genomic sequences of different ssRNA, ssDNA, and dsDNA viruses. The particular representatives included satellite tobacco mosaic virus and the strains of satellite tobacco necrosis virus, STNV-C, STNV-1, STNV-2, Escherichia phages MS2, phiX174, alpha3, and HK97, and Simian virus 40. In all their genomes, we found the significant quasi-regular segmentation of genomic sequences related to the virion assembly and the genome packaging within icosahedral capsid. We also found good correspondence between our results and available cryo-electron microscopy data on capsid structures and genome packaging in these viruses. Fourier analysis of genomic sequences provides the additional insight into mechanisms of hierarchical genome packaging and may be used for verification of the concepts of 3-fold or 5-fold intermediates in virion assembly. The results of sequence analysis should be taken into account at the choice of models and data interpretation. They also may be helpful for the development of antiviral drugs.