Probing Occurrence and Possible Roles of New Insert in Spike Glycoprotein of SARS-CoV-2
42 Pages Posted: 22 May 2020
Date Written: May 15, 2020
Abstract
As a greatest change over closest SARS coronavirus RatG13, novel SARS-CoV-2 bears TCCTCGGCGGGC (12 nucleotides stretch, 12TNs) and PRRA (Pro-Arg-Arg-Ala) residues in spike gene and protein, respectively. PRRA is present adjacent to a Ser residue; strikingly making SPRR stretch of amino acids which is present in surface glycoproteins proteins/spikes of numerous highly contagious animal and human viruses. This study investigates occurrence of SPRR in viral surface proteins and evaluates if these residues might be playing previously unknown role in contributing any advantage to viruses for higher invasion of host cells. A careful evaluation suggests that presence of SPRR could be a hallmark of higher infectivity of host. Results also suggest that presence of SPRR in proteins other than at surface/spikes, make viruses ‘sticky’ for a long-lasting stay in the host cells. An assessment of relation of SPRR residues with furin-cleavage sites has also been evaluated. A simulated loss of SPRR in surface protein models of some viruses including spike of SARS-CoV-2 has been presented suggesting that SPRR is crucial criterion for brining major change during virus-host interaction. An available dataset on SARS-CoV-2 infected lung epithelial cells was analyses for understanding how this virus affects transcripts of furin-cleaved proteins. An inhibition of such transcripts was noted which needs experimental explanation. Site of primary interaction between SARS-CoV-2 and human cell is spike receptor binding domain (RBD)/motif (RBM) and human ACE2 virus binding motif/domain (VBD). VBD reflected sequence homology has been used to predict 50 animals, might be sensitive to SARS-CoV-2 infection.
Note:
Funding: We declare that there is no funding for this study.
Conflict of Interest: The author declares no competing financial interests.
Keywords: SARS Coronavirus-2, Furin, RNAi, COVID-19, Pathogenicity, Host range
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