Kinetic analysis of RNA cleavage by coronavirus Nsp15 endonuclease: Evidence for acid-base catalysis and substrate-dependent metal ion activation.

ABSTRACT: Understanding the functional properties of severe acute respiratory syndrome coronavirus 2 nonstructural proteins is essential for defining their roles in the viral life cycle, developing improved therapeutics and diagnostics, and countering future variants. Coronavirus nonstructural protein Nsp15 is a hexameric U-specific endonuclease whose functions, substrate specificity, mechanism, and dynamics are not fully defined. Previous studies report that Nsp15 requires Mn²⁺ ions for optimal activity; however, the effects of divalent ions on Nsp15 reaction kinetics have not been investigated in detail. Here, we analyzed the single- and multiple-turnover kinetics for model ssRNA substrates. Our data confirm that divalent ions are dispensable for catalysis and show that Mn²⁺

SUBMITTER: Huang T 

PROVIDER: S-EPMC10158045 | biostudies-literature | 2023 Jun

REPOSITORIES: biostudies-literature