7pkp | pdb_00007pkp
NSP2 RNP complex
Structural highlights
Function[A2T3N6_9REOV] Participates in replication and packaging of the viral genome. Plays a crucial role, together with NSP5, in the formation of virus factories (viroplasms) which are large inclusions in the host cytoplasm where replication intermediates are assembled and viral RNA replication takes place. Displays ssRNA binding, NTPase, RNA triphosphatase (RTPase) and ATP-independent helix-unwinding activities. The unwinding activity may prepare and organize plus-strand RNAs for packaging and replication by removing interfering secondary structures. The RTPase activity plays a role in the removal of the gamma-phosphate from the rotavirus RNA minus strands of dsRNA genome segments.[HAMAP-Rule:MF_04089][RuleBase:RU364009] Publication Abstract from PubMedRotavirus genomes are distributed between 11 distinct RNA molecules, all of which must be selectively copackaged during virus assembly. This likely occurs through sequence-specific RNA interactions facilitated by the RNA chaperone NSP2. Here, we report that NSP2 autoregulates its chaperone activity through its C-terminal region (CTR) that promotes RNA-RNA interactions by limiting its helix-unwinding activity. Unexpectedly, structural proteomics data revealed that the CTR does not directly interact with RNA, while accelerating RNA release from NSP2. Cryo-electron microscopy reconstructions of an NSP2-RNA complex reveal a highly conserved acidic patch on the CTR, which is poised toward the bound RNA. Virus replication was abrogated by charge-disrupting mutations within the acidic patch but completely restored by charge-preserving mutations. Mechanistic similarities between NSP2 and the unrelated bacterial RNA chaperone Hfq suggest that accelerating RNA dissociation while promoting intermolecular RNA interactions may be a widespread strategy of RNA chaperone recycling. Structural basis of rotavirus RNA chaperone displacement and RNA annealing.,Bravo JPK, Bartnik K, Venditti L, Acker J, Gail EH, Colyer A, Davidovich C, Lamb DC, Tuma R, Calabrese AN, Borodavka A Proc Natl Acad Sci U S A. 2021 Oct 12;118(41). pii: 2100198118. doi:, 10.1073/pnas.2100198118. PMID:34615715[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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