What does PRRSV structure reveal about its biology?

Problem: Despite the importance of PRRSV, the structures of its proteins and the organization of the virion remained incompletely understood, limiting understanding of relationships between viral structure and function.

Methods: This review synthesized evidence from crystallography, electron microscopy, and biochemical and in vivo studies of PRRSV proteins and protein interactions.

Takeaway 1: Crystal structures were available for the NSP1α, NSP1β and NSP4 proteases and the nucleocapsid protein N.

Takeaway 2: NSP1α and NSP1β structures revealed domains beyond their protease domains that may contribute to modulation of host-cell functions.

Takeaway 3: Cryo-electron tomography suggested an asymmetric, linear nucleocapsid rather than the previously described isometric core, strengthening structural similarities between arteriviruses and coronaviruses.