Strong evolutionary convergence of receptor-binding protein spike between COVID-19 and SARS-related coronaviruses

Yonghua Wu

Our molecular phyloecological study demonstrates that spike protein shows significant Darwinian selection along two ancestral branches related to SARS-CoV and 2019-nCoV, suggesting their adaptive evolution to recognizing their own cell receptors. Comparative sequence and phylogenetic analyses indicate a high similarity of RBD sequences of spike protein between SARS-related CoV and COVID-19related CoV. Subsequent ancestral sequence reconstruction and convergent evolution analyses reveal an unusually high incidence of parallel and convergent amino acid substitutions between them, suggesting an extremely strong adaptive evolutionary convergence in spike protein. In addition to spike protein, we also found evolutionary convergence of its partner protein, ORF3a, suggesting their possible co-evolutionary convergence. Finally, considering that SARS-CoV and 2019-nCoV have posed serious concerns to public health and safety, it should be noted that many other bat SARS-like CoV strains that were evolutionarily convergent with SARS-CoV and 2019-nCoV recognized in this study may be potential novel coronaviruses to infect humans in the future. The copyright holder for this preprint (which was not peer-reviewed) is the . https://doi.org/10.1101/2020.03.04.975995 doi: bioRxiv preprint