Structure of Aichi Virus 1 and Its Empty Particle: Clues to Kobuvirus Genome Release Mechanism.Sabin, C., Fuzik, T., Skubnik, K., Palkova, L., Lindberg, A.M., Plevka, P.
(2016) J.Virol. 90: 10800-10810
- PubMed: 27681122
- DOI: 10.1128/JVI.01601-16
- PubMed Abstract:
Aichi virus 1 (AiV-1) is a human pathogen from the Kobuvirus genus of the Picornaviridae family. Worldwide, 80-95% of adults have antibodies against the virus. AiV-1 infections are associated with nausea, gastroenteritis, and fever. Unlike most picor ...
Aichi virus 1 (AiV-1) is a human pathogen from the Kobuvirus genus of the Picornaviridae family. Worldwide, 80-95% of adults have antibodies against the virus. AiV-1 infections are associated with nausea, gastroenteritis, and fever. Unlike most picornaviruses, kobuvirus capsids are composed of only three types of subunits: VP0, VP1, and VP3. Here we present the structure of the AiV-1 virion determined to a resolution of 2.1 Å using X-ray crystallography. The surface loops puff of VP0 and knob of VP3 in AiV-1 are shorter than those in other picornaviruses. Instead, the 42-residue-long BC-loop of VP0 forms the most prominent surface feature of the AiV-1 virion. We determined the structure of AiV-1 empty particle to a resolution of 4.2 Å using cryo-electron microscopy. The empty capsids are expanded relative to the native virus. The N-terminal arms of capsid proteins VP0, which mediate contacts between the pentamers of capsid protein protomers in the native AiV-1 virion, are disordered in the empty capsid. Nevertheless, the empty particles are stable, at least in vitro, and do not contain pores that might serve as channels for genome release. Therefore, extensive and probably reversible local reorganization of AiV-1 capsid is required for its genome release.
Structural Virology, Central European Institute of Technology, Masaryk University, Kamenice 753/5, 62500 Brno, Czech Republic.