Title

Cryo-electron Tomography of Porcine Reproductive and Respiratory Syndrome Virus: Organization of the Nucleocapsid

Document Type

Article

Publication Date

3-2009

Abstract

Porcine reproductive and respiratory virus (PRRSV) is an enveloped positive-sense RNA virus of the familyArteriviridae that causes severe and persistent disease in pigs worldwide. The PRRSV virion consists of a lipid envelope that contains several envelope proteins surrounding a nucleocapsid core that encapsidates the RNA genome. To provide a better understanding of the structure and assembly of PRRSV, we have carried out cryo-electron microscopy and tomographic reconstruction of virions grown in MARC-145 cells. The virions are pleomorphic, round to egg-shaped particles with an average diameter of 58 nm. The particles display a smooth outer surface with only a few protruding features, presumably corresponding to the envelope protein complexes. The virions contain a double-layered, hollow core with an average diameter of 39 nm, which is separated from the envelope by a 2–3 nm gap. Analysis of the three-dimensional structure suggests that the core is composed of a double-layered chain of nucleocapsid proteins bundled into a hollow ball.

Publication Title

Journal of General Virology

Volume

90

Issue

3

First Page

527

Last Page

535

DOI of Published Version

10.1099/vir.0.007674-0

Publisher

Microbiology Society