Emerging mutations in spike and other structural proteins of SARS-CoV-2

The structural proteins, spike (S), nucleocapsid (N), membrane (M), and envelope (E), of severe acute respiratory syndrome (SARS-CoV-2) play a critical role from attachment to replication and virulency. Recently a bulk of genomes have been sequenced from different geographical regions with significant number of variations. Therefore, the current study was aimed to find variations in the structural proteins. This is the first comprehensive study in which we screened 2,95,000 complete genomes in global initiative on sharing all influenza data (GISAID), submitted from December 2019 to December 2020. We detected 4725 non-synonymous mutations in S, 627 in M, 259 in E, and 1631 mutations in N protein, among which the most frequently occurring mutations in S protein are D614G (n=2,66,513), A222V (n=59,697), L18F (n=28,015) and that of M protein are; T175M (n=1286), D3G (n=968), L17I (n=621), A2V (n=463), and A2S (n=460). The most commonly circulating variants in E includes, S68F (n=419), P71S (n=264), and L73F (n=218). Similarly, the N protein also harbored the most common variants which include; R203K (n=82,570), G204R (n=81,858), and A220V (n=39,729). The frequency of N501Y (n=4362) in S is determining a tight interaction of CoV-2 RBD with ACE2. These wide range of mutations in structural proteins may not only affect the therapeutic efforts but also the vaccines efficacy and diagnostics specificity. We suggest that geographically strain specific variations should be investigated for effective drugs, vaccine, and the antibodies combinations. Alternatively, immune boosting compounds might be very useful for successful eradication of CoV-2 infections.