Computational simulation of interactions between SARS coronavirus spike mutants and host species-specific receptors

As a critical adaptive mechanism, amino acid replacements on the severe acute respiratory syndrome coronavirus (SARS-CoV) spike protein could alter the receptor-binding specificity of this envelope glycoprotein and in turn lead to the emergence or reemergence of this viral zoonosis. Based on the X-ray structures of SARS-CoV spike receptor-binding domain (RBD) in complex with its functional receptor (angiotensin-converting enzyme 2, ACE2), we perform computational simulations of interactions between three representative RBD mutants and four host species-specific receptors. The comparisons between computational predictions and experimental evidences validate our structural bioinformatics approaches. And the predictions further indicate that some viral prototypes might utilize the rat ACE2 while rats might serve as a vector or reservoir of SARS-CoV.