Figure 3.

The multiple sequence alignment of spike (S) glycoprotein along with S1/S2 and S2ʹ cleavage sites. The proprotein convertase (PPC) or furin motif RRAR with leading proline insertion is unique to SARS‐CoV‐2 (PRRA insertion highlighted in red box) although NL63 and MERS have proline without downstream additional basic residues. Such polybasic cleavage site is absent in other beta CoVs including bat, Chinese as well as Malayan pangolin, and even previous human SARS‐CoV. The S2ʹ cleavage site at R815 is conserved across all the sequences analyzed; however, SARS‐CoV‐2, bat, and pangolin has KPSKR and civet and hSARS‐CoV has KPTKR