Studies conducted over the past decade have demonstrated how the SARS virus (SARS-CoV) infects animal and human host cells. Now, a study published January 29, 2020 in the Journal of Virology finds that the Wuhan coronavirus (2019-nCoV) uses the same receptors as the SARS CoV to gain entry into cells.
The researchers compared previous data on the SARS-CoV spike protein receptor-binding domain 30 (RBD), which recognizes angiotensin-converting enzyme-2 (ACE2) host receptors, with the newly released sequence of the Wuhan coranovirus. They found that the 2019-nCoV RBD sequence is similar to that of SARS-CoV, suggesting that 2019-nCoV also uses ACE2 as its host receptor. Several critical residues in the 2019-nCoV RBM provide favorable interactions with human ACE2, consistent with 2019-nCoV's capacity for human cell infection, the researchers report. Other critical residues in 2019-nCoV RBM are compatible with, but not ideal for, binding human ACE2, suggesting that 2019-nCoV has acquired some capacity for human-to-human transmission. While their phylogenetic analyses indicate a bat origin of 2019-nCoV, the researchers write that the virus also potentially recognizes ACE2 from a variety of animal species including pigs, ferrets, cats, and non-human primates, any of which could potentially serve as intermediate hosts for 2019-nCoV infections.
Notably, the study also finds that a single mutation could significantly enhance the Wuhan coronavirus's ability to bind with human ACE2. Therefore, the authors recommend that viral evolution in patients be closely monitored for the emergence of novel mutations, in order to predict the possibility of a more serious outbreak.