Reconstructing an Icosahedral Virus from Single-Particle Diffraction Experiments

TL;DR

This paper introduces a method to reconstruct 3D images of icosahedral viruses from low-resolution diffraction data obtained via free electron laser experiments, enabling detailed structural analysis from single-particle scattering.

Contribution

It presents a simple test for confirming icosahedral symmetry and an efficient algorithm for combining diffraction data from multiple shots to reconstruct virus structures.

Findings

Successful simulation reconstruction of satellite tobacco necrosis virus

Effective angular correlation test for symmetry verification

Potential for high-resolution virus imaging from FEL data

Abstract

The first experimental data from single-particle scattering experiments from free electron lasers (FELs) are now becoming available. The first such experiments are being performed on relatively large objects such as viruses, which produce relatively low-resolution, low-noise diffraction patterns in so-called "diffract-and-destroy" experiments. We describe a very simple test on the angular correlations of measured diffraction data to determine if the scattering is from an icosahedral particle. If this is confirmed, the efficient algorithm proposed can then combine diffraction data from multiple shots of particles in random unknown orientations to generate a full 3D image of the icosahedral particle. We demonstrate this with a simulation for the satellite tobacco necrosis virus (STNV), the atomic coordinates of whose asymmetric unit is given in Protein Data Bank entry 2BUK.