Download MendeleyCrystal structure of a nematode-infecting virus.
Guo, Y.R., Hryc, C.F., Jakana, J., Jiang, H., Wang, D., Chiu, W., Zhong, W., Tao, Y.J.(2014) Proc Natl Acad Sci U S A 111: 12781-12786
- PubMed: 25136116
- DOI: https://doi.org/10.1073/pnas.1407122111
- Primary Citation of Related Structures:
4NWV, 4NWW - PubMed Abstract:
Orsay, the first virus discovered to naturally infect Caenorhabditis elegans or any nematode, has a bipartite, positive-sense RNA genome. Sequence analyses show that Orsay is related to nodaviruses, but molecular characterizations of Orsay reveal several unique features, such as the expression of a capsid-δ fusion protein and the use of an ATG-independent mechanism for translation initiation. Here we report the crystal structure of an Orsay virus-like particle assembled from recombinant capsid protein (CP). Orsay capsid has a T = 3 icosahedral symmetry with 60 trimeric surface spikes. Each CP can be divided into three regions: an N-terminal arm that forms an extended protein interaction network at the capsid interior, an S domain with a jelly-roll, β-barrel fold forming the continuous capsid, and a P domain that forms surface spike projections. The structure of the Orsay S domain is best aligned to T = 3 plant RNA viruses but exhibits substantial differences compared with the insect-infecting alphanodaviruses, which also lack the P domain in their CPs. The Orsay P domain is remotely related to the P1 domain in calicivirus and hepatitis E virus, suggesting a possible evolutionary relationship. Removing the N-terminal arm produced a slightly expanded capsid with fewer nucleic acids packaged, suggesting that the arm is important for capsid stability and genome packaging. Because C. elegans-Orsay serves as a highly tractable model for studying viral pathogenesis, our results should provide a valuable structural framework for further studies of Orsay replication and infection.
Organizational Affiliation:
Department of BioSciences, Rice University, Houston, TX 77005;
