Averaging of viral envelope glycoprotein spikes from electron cryotomography reconstructions using Jsubtomo

Juha T Huiskonen, Marie-Laure Parsy, Sai Li, David Bitto, Max Renner, Thomas A Bowden

Research output: Contribution to journalArticle (Academic Journal)peer-review

Abstract

Enveloped viruses utilize membrane glycoproteins on their surface to mediate entry into host cells. Three-dimensional structural analysis of these glycoprotein 'spikes' is often technically challenging but important for understanding viral pathogenesis and in drug design. Here, a protocol is presented for viral spike structure determination through computational averaging of electron cryo-tomography data. Electron cryo-tomography is a technique in electron microscopy used to derive three-dimensional tomographic volume reconstructions, or tomograms, of pleomorphic biological specimens such as membrane viruses in a near-native, frozen-hydrated state. These tomograms reveal structures of interest in three dimensions, albeit at low resolution. Computational averaging of sub-volumes, or sub-tomograms, is necessary to obtain higher resolution detail of repeating structural motifs, such as viral glycoprotein spikes. A detailed computational approach for aligning and averaging sub-tomograms using the Jsubtomo software package is outlined. This approach enables visualization of the structure of viral glycoprotein spikes to a resolution in the range of 20-40 Å and study of the study of higher order spike-to-spike interactions on the virion membrane. Typical results are presented for Bunyamwera virus, an enveloped virus from the family Bunyaviridae. This family is a structurally diverse group of pathogens posing a threat to human and animal health.

Original languageEnglish
Pages (from-to)e51714
JournalJournal of visualized experiments : JoVE
Issue number92
DOIs
Publication statusPublished - 21 Oct 2014

Keywords

  • Bunyamwera virus/chemistry
  • Electron Microscope Tomography/methods
  • Glycoproteins/analysis
  • Software
  • Viral Envelope Proteins/analysis

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