Defining substrate selection by rhinoviral 2A proteinase through its crystal structure with the inhibitor zVAM.fmk

Virology. 2021 Oct:562:128-141. doi: 10.1016/j.virol.2021.07.008. Epub 2021 Jul 21.

Abstract

Picornavirus family members cause disease in humans. Human rhinoviruses (RV), the main causative agents of the common cold, increase the severity of asthma and COPD; hence, effective agents against RVs are required. The 2A proteinase (2Apro), found in all enteroviruses, represents an attractive target; inactivating mutations in poliovirus 2Apro result in an extension of the VP1 protein preventing infectious virion assembly. Variations in sequence and substrate specificity on eIF4G isoforms between RV 2Apro of genetic groups A and B hinder 2Apro as drug targets. Here, we demonstrate that although RV-A2 and RV-B4 2Apro cleave the substrate GAB1 at different sites, the 2Apro from both groups cleave equally efficiently an artificial site containing P1 methionine. We determined the RV-A2 2Apro structure complexed with zVAM.fmk, containing P1 methionine. Analysis of this first 2Apro-inhibitor complex reveals a conserved hydrophobic P4 pocket among enteroviral 2Apro as a potential target for broad-spectrum anti-enteroviral inhibitors.

Keywords: Anti-viral agent; Cysteine proteinase; Fluoromethylketone inhibitor; Rhinovirus; Translation initiation; Virus-host interaction.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing / metabolism
  • Amino Acid Sequence
  • Antiviral Agents / chemistry*
  • Cysteine Endopeptidases / chemistry*
  • Cysteine Endopeptidases / genetics
  • Cysteine Endopeptidases / metabolism*
  • Enterovirus / chemistry
  • Enterovirus / enzymology
  • Eukaryotic Initiation Factor-4G / metabolism
  • Genetic Variation
  • HeLa Cells
  • Humans
  • Protein Conformation
  • Rhinovirus / chemistry
  • Rhinovirus / enzymology*
  • Rhinovirus / genetics
  • Substrate Specificity
  • Viral Proteins / antagonists & inhibitors
  • Viral Proteins / chemistry*
  • Viral Proteins / genetics
  • Viral Proteins / metabolism*

Substances

  • Adaptor Proteins, Signal Transducing
  • Antiviral Agents
  • Eukaryotic Initiation Factor-4G
  • GAB1 protein, human
  • Viral Proteins
  • Cysteine Endopeptidases
  • picornain 2A, Picornavirus