The emergence of a novel SARS-CoV-2 variant with higher efficiency of binding with the human host cell receptors in Iraqi subjects

The objective of this study was to assess the impact of variations in the surface glycoprotein of SARS-CoV-2, which is generated by the spike (S) gene, on its interaction with host receptors in seventy-six viral Iraqi samples. Out of seven SNPs in the coding regions, three missense SNPs were identified. Based on phylogenetic analysis, four distinct groups of amino acid variations were revealed. In group-1 (p.N655H), group-2 (p.H622D), and group-3 (p.L449R), one missense SNP was observed, while no missense SNP was identified in the group-4 (wild-type) samples. Due to their novel amino acid variations, both group-1 and group-2 variants occupied two distinct phylogenetic positions in the tree. Molecular docking was performed between the identified S gene variants and the host angiotensin-converting enzyme 2 (ACE2) receptor, and the effects of these variants were evaluated. Compared with the other viral variations, docking revealed that p.N655H variant exhibited the highest affinity to the ACE2 receptor. It was found that patients infected with p.N655H variants showed a higher level of severity compared to the other types of infections. In conclusion, the observed p.N655H was associated with a higher severity of SARS-CoV-2 infection, which may be associated with greater host entry capacity compared to the wild type or other identified variants. These findings provide insights into the mechanism by which these novel viral strains interact with host cell receptors. They also highlight the importance of understanding virus-host interactions for assessing the impact of the global pandemic caused by SARS-CoV-2.