Comparative genomic analysis revealed specific mutation pattern between human coronavirus SARS-CoV-2 and Bat-SARSr-CoV RaTG13

Longxian Lv; Gaolei Li; Jinhui Chen; Xinle Liang; Yudong Li

The spike (S) protein undergoes several drastic changes during virus infection. For instance, its large parts are cleaved during infection by cellular proteases and expose the receptors to activate viral attachment to the host (17) . As the receptor binding domain (RBD) of spike protein was involved in interacting with human angiotensin-converting enzyme 2 (ACE2) protein, the RBD region was thought to be preferential targets of natural selection (18) . Consistent with this hypothesis, our results showed that both dN and dS of RBD region are increased in comparison with whole spike gene region across all the virus pairs used in this study (Table 1) . Notably, the dN/dS ratio of RBD region in SARS-CoV-2 WIV04 was dramatically increased in about 3 fold in comparison with full spike region. Consequently, these mutations may be subjected to Darwin's choice and will become evidence of adaptive protein evolution.