The interaction between the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and angiotensin-converting enzyme 2 (ACE2), the primary entry receptor for SARS-CoV-2, is a key determinant of the range of hosts that can be infected by the virus. Zhang et al. (1) reportedly constructed human ACE2 (hACE2) with the Y217N mutation and found that this mutation completely blocked SARS-CoV-2 entry. Zhang et al. (1) performed an receptor binding domain (RBD) binding assay and found that WT hACE2 potently bound the RBD; however, hACE2 Y217N almost lost the ability to bind the RBD.
