Cryo-EM structure of a Marseilleviridae virus particle reveals a large internal microassembly

Kenta Okamoto; Naoyuki Miyazaki; Hemanth K N Reddy; Max F Hantke; Filipe R N C Maia; Daniel S D Larsson; Chantal Abergel; Jean-Michel Claverie; Janos Hajdu; Kazuyoshi Murata; Martin Svenda

doi:10.1016/j.virol.2018.01.021

Cryo-EM structure of a Marseilleviridae virus particle reveals a large internal microassembly

Virology. 2018 Mar:516:239-245. doi: 10.1016/j.virol.2018.01.021.

Affiliations

¹ Laboratory of Molecular Biophysics, Department of Cell and Molecular Biology, Uppsala University, Husargatan 3 (Box 596), SE-75124 Uppsala, Sweden. Electronic address: kenta.okamoto@icm.uu.se.
² National Institute for Physiological Sciences (NIPS), Okazaki, Aichi, 444-8585 Japan.
³ Laboratory of Molecular Biophysics, Department of Cell and Molecular Biology, Uppsala University, Husargatan 3 (Box 596), SE-75124 Uppsala, Sweden.
⁴ Structural and Genomic Information Laboratory, UMR 7256 (IMM FR 3479) Centre National de la Recherche Scientifique & Aix-Marseille University, Marseille 13288, France.
⁵ Structural and Genomic Information Laboratory, UMR 7256 (IMM FR 3479) Centre National de la Recherche Scientifique & Aix-Marseille University, Marseille 13288, France; Assistance Publique des Hôpitaux de Marseille, La Timone, 13005 Marseille, France.
⁶ Laboratory of Molecular Biophysics, Department of Cell and Molecular Biology, Uppsala University, Husargatan 3 (Box 596), SE-75124 Uppsala, Sweden; Institute of Physics AS CR, v.v.i., Na Slovance 2, 18221 Prague 8, Czech Republic.
⁷ National Institute for Physiological Sciences (NIPS), Okazaki, Aichi, 444-8585 Japan. Electronic address: kazum@nips.ac.jp.

PMID: 29407382
DOI: 10.1016/j.virol.2018.01.021

Abstract

Nucleocytoplasmic large DNA viruses (NCLDVs) blur the line between viruses and cells. Melbournevirus (MelV, family Marseilleviridae) belongs to a new family of NCLDVs. Here we present an electron cryo-microscopy structure of the MelV particle, with the large triangulation number T = 309 constructed by 3080 pseudo-hexagonal capsomers. The most distinct feature of the particle is a large and dense body (LDB) consistently found inside all particles. Electron cryo-tomography of 147 particles shows that the LDB is preferentially located in proximity to the probable lipid bilayer. The LDB is 30 nm in size and its density matches that of a genome/protein complex. The observed LDB reinforces the structural complexity of MelV, setting it apart from other NCLDVs.

Keywords: Amoeba; Capsid; Cryo-electron microscopy; Marseilleviridae; Melbournevirus; NCLDV; Protein complex; Structure; Tomography; Virus.

Publication types

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

MeSH terms

Capsid / metabolism
Capsid / ultrastructure
Cryoelectron Microscopy
DNA Viruses / genetics
DNA Viruses / physiology*
DNA Viruses / ultrastructure*
Genome, Viral
Viral Proteins / genetics
Viral Proteins / metabolism
Virion / genetics
Virion / physiology*
Virion / ultrastructure*
Virus Assembly

Substances

Viral Proteins