SARS‐CoV‐2: Structural diversity, phylogeny, and potential animal host identification of spike glycoprotein

Dabravolski, Siarhei Alexander; Kavalionak, Yury Kazimirovich

To investigate the evolutionary history of the current pandemic outbreak of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2), a total of 137 genomes of coronavirus strains with release dates between January 2019 and 25 March 2020, were analyzed. To investigate the potential intermediate host of the SARS‐CoV‐2, we analyzed spike glycoprotein sequences from different animals, with particular emphasis on bats. We performed phylogenetic analysis and structural reconstruction of the spike glycoproteins with subsequent alignment and comparison. Our phylogenetic results revealed that SARS‐CoV‐2 was more similar to the bats' betacoronavirus isolates: HKU5‐related from Pipistrellus abramus and HKU4‐related from Tylonycteris pachypus. We also identified a yak betacoronavirus strain, YAK/HY24/CH/2017, as the closest match in the comparison of the structural models of spike glycoproteins. Interestingly, a set of unique features has been described for this particular strain of the yak betacoronavirus. Therefore, our results suggest that the human SARS‐CoV‐2, responsible for the current outbreak of COVID‐19, could also come from yak as an intermediate host.