Kinetic and structural analysis of coxsackievirus B3 receptor interactions and formation of the A-particle

J Virol. 2014 May;88(10):5755-65. doi: 10.1128/JVI.00299-14. Epub 2014 Mar 12.


The coxsackievirus and adenovirus receptor (CAR) has been identified as the cellular receptor for group B coxsackieviruses, including serotype 3 (CVB3). CAR mediates infection by binding to CVB3 and catalyzing conformational changes in the virus that result in formation of the altered, noninfectious A-particle. Kinetic analyses show that the apparent first-order rate constant for the inactivation of CVB3 by soluble CAR (sCAR) at physiological temperatures varies nonlinearly with sCAR concentration. Cryo-electron microscopy (cryo-EM) reconstruction of the CVB3-CAR complex resulted in a 9.0-Å resolution map that was interpreted with the four available crystal structures of CAR, providing a consensus footprint for the receptor binding site. The analysis of the cryo-EM structure identifies important virus-receptor interactions that are conserved across picornavirus species. These conserved interactions map to variable antigenic sites or structurally conserved regions, suggesting a combination of evolutionary mechanisms for receptor site preservation. The CAR-catalyzed A-particle structure was solved to a 6.6-Å resolution and shows significant rearrangement of internal features and symmetric interactions with the RNA genome.

Importance: This report presents new information about receptor use by picornaviruses and highlights the importance of attaining at least an ∼9-Å resolution for the interpretation of cryo-EM complex maps. The analysis of receptor binding elucidates two complementary mechanisms for preservation of the low-affinity (initial) interaction of the receptor and defines the kinetics of receptor-catalyzed conformational change to the A-particle.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Binding Sites
  • Coxsackie and Adenovirus Receptor-Like Membrane Protein / metabolism*
  • Cryoelectron Microscopy
  • Enterovirus B, Human / physiology*
  • Enterovirus B, Human / ultrastructure*
  • Kinetics
  • Models, Molecular
  • Molecular Sequence Data
  • Protein Binding
  • Protein Conformation
  • Virion / metabolism
  • Virion / ultrastructure
  • Virus Attachment*
  • Virus Inactivation


  • Coxsackie and Adenovirus Receptor-Like Membrane Protein