Structural basis for the regulatory function of a complex zinc-binding domain in a replicative arterivirus helicase resembling a nonsense-mediated mRNA decay helicase

Zengqin Deng, Kathleen C. Lehmann, Xiaorong Li, Chong Feng, Guoqiang Wang, Qi Zhang, Xiaoxuan Qi, Lin Yu, Xingliang Zhang, Wenhai Feng, Wei Wu, Peng Gong, Ye Tao, Clara C. Posthuma, Eric J. Snijder, Alexander E. Gorbalenya, Zhongzhou Chen

Research output: Contribution to journalArticleResearchpeer-review

28 Citations (Scopus)


All positive-stranded RNA viruses with genomes > ∼7 kb encode helicases, which generally are poorly characterized. The core of the nidovirus superfamily 1 helicase (HEL1) is associated with a unique N-terminal zinc-binding domain (ZBD) that was previously implicated in helicase regulation, genome replication and subgenomic mRNA synthesis. The high-resolution structure of the arterivirus helicase (nsp10), alone and in complex with a polynucleotide substrate, now provides first insights into the structural basis for nidovirus helicase function. A previously uncharacterized domain 1B connects HEL1 domains 1A and 2A to a long linker of ZBD, which further consists of a novel RING-like module and treble-clef zinc finger, together coordinating three Zn atoms. On substrate binding, major conformational changes were evident outside the HEL1 domains, notably in domain 1B. Structural characterization, mutagenesis and biochemistry revealed that helicase activity depends on the extensive relay of interactions between the ZBD and HEL1 domains. The arterivirus helicase structurally resembles the cellular Upf1 helicase, suggesting that nidoviruses may also use their helicases for post-transcriptional quality control of their large RNA genomes.
Original languageEnglish
Article numbergkt1310
Pages (from-to)3464-3477
Number of pages14
JournalNucleic Acids Research
Issue number5
Publication statusPublished - 1 Mar 2014
Externally publishedYes

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