Cryo-Electron Microscopy Structure of the Macrobrachium rosenbergii Nodavirus Capsid at 7 Angstroms Resolution

• Published in: Scientific reports 2017-05, Vol.7 (1), p.2083-8, Article 2083
• Main Authors: Ho, Kok Lian, Kueh, Chare Li, Beh, Poay Ling, Tan, Wen Siang, Bhella, David
• Format: Article
• Language: English
• Subjects: 101/28; 631/326/596/2148; 631/535/1258/1259; Animals; Aquaculture; Capsid - ultrastructure; Capsid protein; Developing countries; Electron microscopy; Farms; Hatcheries; Humanities and Social Sciences; LDCs; Macrobrachium rosenbergii; multidisciplinary; New genera; Nodaviridae - classification; Nodaviridae - ultrastructure; Palaemonidae - virology; Pest outbreaks; Science; Science (multidisciplinary); Shellfish; Virus-like particles
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-017-02292-0

White tail disease in the giant freshwater prawn Macrobrachium rosenbergii causes significant economic losses in shrimp farms and hatcheries and poses a threat to food-security in many developing countries. Outbreaks of Macrobrachium rosenbergii nodavirus ( Mr NV), the causative agent of white tail disease (WTD) are associated with up to 100% mortality rates. There are no interventions available to treat or prevent Mr NV disease however. Here we show the structure of Mr NV virus-like particles (VLPs) produced by recombinant expression of the capsid protein, using cryogenic electron microscopy. Our data show that Mr NV VLPs package nucleic acids in a manner reminiscent of other known nodavirus structures. The structure of the capsid however shows striking differences from insect and fish infecting nodaviruses, which have been shown to assemble trimer-clustered T = 3 icosahedral virus particles. Mr NV particles have pronounced dimeric blade-shaped spikes extending up to 6 nm from the outer surface of the capsid shell. Our structural analysis supports the assertion that Mr NV may belong to a new genus of the Nodaviridae . Moreover, our study provides the first structural view of an important pathogen affecting aquaculture industries across the world.