Characterization of SARS2 Nsp15 nuclease activity reveals it's mad about U.

Journal Article (Journal Article)

Nsp15 is a uridine specific endoribonuclease that coronaviruses employ to cleave viral RNA and evade host immune defense systems. Previous structures of Nsp15 from across Coronaviridae revealed that Nsp15 assembles into a homo-hexamer and has a conserved active site similar to RNase A. Beyond a preference for cleaving RNA 3' of uridines, it is unknown if Nsp15 has any additional substrate preferences. Here, we used cryo-EM to capture structures of Nsp15 bound to RNA in pre- and post-cleavage states. The structures along with molecular dynamics and biochemical assays revealed critical residues involved in substrate specificity, nuclease activity, and oligomerization. Moreover, we determined how the sequence of the RNA substrate dictates cleavage and found that outside of polyU tracts, Nsp15 has a strong preference for purines 3' of the cleaved uridine. This work advances our understanding of how Nsp15 recognizes and processes viral RNA, and will aid in the development of new anti-viral therapeutics.

Full Text

Duke Authors

Cited Authors

  • Frazier, MN; Dillard, LB; Krahn, JM; Perera, L; Williams, JG; Wilson, IM; Stewart, ZD; Pillon, MC; Deterding, LJ; Borgnia, MJ; Stanley, RE

Published Date

  • September 2021

Published In

Volume / Issue

  • 49 / 17

Start / End Page

  • 10136 - 10149

PubMed ID

  • 34403466

Pubmed Central ID

  • PMC8385992

Electronic International Standard Serial Number (EISSN)

  • 1362-4962

International Standard Serial Number (ISSN)

  • 0305-1048

Digital Object Identifier (DOI)

  • 10.1093/nar/gkab719


  • eng