Correction: The Murine Coronavirus Hemagglutinin-esterase Receptor-binding Site: A Major Shift in Ligand Specificity through Modest Changes in Architecture
Martijn A. Langereis, Qinghong Zeng, Balthasar A. Heesters, Eric G. Huizinga, Raoul J. de Groot · PLoS Pathogens · 2012
The hemagglutinin-esterases (HEs), envelope glycoproteins of corona-, toro-and orthomyxoviruses, mediate reversible virion attachment to O-acetylated sialic acids (O-Ac-Sias).They do so through concerted action of distinct receptor-binding (''lectin'') and receptor-destroying sialate O-acetylesterase (''esterase'') domains.Most HEs target 9-O-acetylated Sias.In one lineage of murine coronaviruses, however, HE esterase substrate and lectin ligand specificity changed dramatically as these viruses evolved to use 4-O-acetylated Sias instead.Here we present the crystal structure of the lectin domain of mouse hepatitis virus (MHV) strain S HE, resolved both in its native state and in complex with a receptor analogue.The data show that the shift from 9-O-to 4-O-Ac-Sia receptor usage primarily entailed a change in ligand binding topology and, surprisingly, only modest changes in receptor-binding site architecture.Our findings illustrate the ease with which viruses can change receptor-binding specificity with potential consequences for host-, organ and/or cell tropism, and for pathogenesis.