Structural Insights into Common and Host-Specific Receptor-Binding Mechanisms in Algal Picorna-like Viruses

Han Wang; Anna Munke; Siqi Li; Yuji Tomaru; Kenta Okamoto

doi:10.3390/v14112369

Structural Insights into Common and Host-Specific Receptor-Binding Mechanisms in Algal Picorna-like Viruses

Viruses. 2022 Oct 27;14(11):2369. doi: 10.3390/v14112369.

Authors

Han Wang¹, Anna Munke^{1

2}, Siqi Li¹, Yuji Tomaru³, Kenta Okamoto¹

Affiliations

¹ The Laboratory of Molecular Biophysics, Department of Cell and Molecular Biology, Uppsala University, 75124 Uppsala, Sweden.
² Center for Free-Electron Laser Science CFEL, Deutsches Elektronen-Synchrotron DESY, 22607 Hamburg, Germany.
³ Fisheries Technology Institute, Japan Fisheries Research and Education Agency, Hatsukaichi 739-0452, Hiroshima, Japan.

Abstract

Marnaviridae viruses are abundant algal viruses that regulate the dynamics of algal blooms in aquatic environments. They employ a narrow host range because they merely lyse their algal host species. This host-specific lysis is thought to correspond to the unique receptor-binding mechanism of the Marnaviridae viruses. Here, we present the atomic structures of the full and empty capsids of Chaetoceros socialis forma radians RNA virus 1 built-in 3.0 Å and 3.1 Å cryo-electron microscopy maps. The empty capsid structure and the structural variability provide insights into its assembly and uncoating intermediates. In conjunction with the previously reported atomic model of the Chaetoceros tenuissimus RNA virus type II capsid, we have identified the common and diverse structural features of the VP1 surface between the Marnaviridae viruses. We have also tested the potential usage of AlphaFold2 for structural prediction of the VP1s and a subsequent structural phylogeny for classifying Marnaviridae viruses by their hosts. These findings will be crucial for inferring the host-specific receptor-binding mechanism in Marnaviridae viruses.

Keywords: Marnaviridae; algal bloom; algal viruses; icosahedral viruses; ssRNA viruses.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Capsid / chemistry
Capsid Proteins / chemistry
Cryoelectron Microscopy
Phycodnaviridae*
RNA Viruses* / genetics
Viruses*

Substances

Capsid Proteins

Grants and funding

Funding was provided by the following agencies: The Swedish Research Council (to K.O., grant number: 2018-03387), the Swedish Foundation for International Cooperation in Research and Higher Education (STINT) (to Janos Hajdu and K.O., grant number: JA2014-5721), FORMAS research grant from the Swedish Research Council for Environment, Agricultural Sciences and Spatial Planning (to K.O., grant number: 2018-00421), Royal Swedish Academy of Sciences (to K.O., grant number: BS2018-0053) and JSPS KAKENHI (to Y.T., grant numbers: 19H00956 and 22K18351).