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)