Identification of an Intramolecular Switch That Controls the Interaction of Helicase nsp10 with Membrane-Associated nsp12 of Porcine Reproductive and Respiratory Syndrome Virus
Yunhao Hu, Purui Ke, Peng Gao, Yongning Zhang, Lei Zhou, Xinna Ge, Xin Guo, Jun Han, Hanchun Yang
Abstract
Assembly of replication and transcription complexes (RTC) is a limiting step for viral RNA synthesis. The PRRSV RTC macromolecular complexes are comprised of mainly viral nonstructural replicase proteins (nsps), but how they come together remains elusive. We previously showed that viral helicase nsp10 interacts nsp12 in a regulated manner by truncation mutagenesis. Here, we revealed that the interaction is controlled by single residues within the domain linker region of nsp10. Moreover, the activation mutations lead to defects in viral sgRNA synthesis. Our results provide important insight into the mechanisms of PRRSV RTC assembly and regulation of viral sgRNA synthesis.