Susceptibility of spike glycoprotein and RNA-dependent RNA polymerase of SARS-CoV-2 to mutation: in silico structural dynamics study

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a microorganism that causes coronavirus disease 2019 (COVID-19). Mutations affect evolutionary conservation of microorganisms. The fast pace evolutionary changes are currently affecting pathogenicity of SARS-CoV-2. In this study, the structural fluctuations of the amino acid residues in the spike glycoprotein and RNA-dependent RNA polymerase (nsp12) of SARS-CoV-2 were investigated by in silico approach using structural flexibility dynamics to decipher susceptibility to mutation. The result of this study implicated key amino acid residues (with rmsf) which could be very susceptible to mutation, which include residues 50 (3.79 Å), 119 (4.56 Å), 120 (3.53 Å), 220 (3.84 Å), 265 (4.31 Å) of RNA-dependent RNA polymerase (nsp12), as well as residues 477 (4.21 Å), 478 (4.82 Å), 479 (5.40 Å), 481 (5.94 Å), 560 (4.63 Å), 704 (4.02 Å), 848 (4.58 Å), 1144 (4.56 Å) and 1147 (4.61 Å) of spike glycoprotein. The SARS-CoV-2 mutations destabilized the overall protein structure in multiples of amino acid residues which could interfere with active site leading to insensitivity or resistance to the inhibitors. Mutation T478K of Spike glycoprotein showed the highest deviation in the structure. Overall, spike glycoprotein has the highest number of mutations, and these variants could increase the risk to human health if not mitigated in the population.