Conformational Characterization of Linker Revealed the Mechanism of Cavity Formation by 227G in BVDV RDRP

J Phys Chem B. 2019 Jul 25;123(29):6150-6160. doi: 10.1021/acs.jpcb.9b01859. Epub 2019 Jul 11.

Abstract

RNA-dependent RNA polymerase (RdRp) is a relevant antiviral drug target. We investigated a potent benzimidazole inhibitor (227G; IC50 = 0.002 μM) against bovine viral diarrhea virus (BVDV) RdRp; however, its inhibition action was completely impaired in the presence of a resistant mutation, I261M. The binding of 227G in mutant RdRp affected the binding site loop conformations (especially Linker) that increased the volume of the binding site. It was also observed that the innate Linker's flexibility was retained, which was otherwise completely frozen in the wild-type complex. The functional role of Linker was hypothesized that it is a multidocking site for RNA template, inhibitors, and the other proteins involved in replication complex formation. The binding phenomenon requires significant molecular flexibility and the large-amplitude conformational dynamics of Linker, which is currently unknown. We observed a bidirectional "hinge"-like motion of Linker from crystal position, indicating its pronounced flexible behavior. This study underscores the importance of Linker's flexibility in the functionality of BVDV RdRp and proposes the template entrance site for selective anti-BVDV drug discovery.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Binding Sites
  • Diarrhea Viruses, Bovine Viral / enzymology*
  • Molecular Docking Simulation
  • Molecular Dynamics Simulation
  • Movement
  • Mutation
  • Protein Conformation
  • RNA-Dependent RNA Polymerase / chemistry*
  • RNA-Dependent RNA Polymerase / genetics
  • RNA-Dependent RNA Polymerase / metabolism

Substances

  • RNA-Dependent RNA Polymerase