Asit Kumar Chakraborty*
Associate Professor of Biochemistry, Department of Biotechnology and Biochemistry, Oriental Institute of Science and Technology, West Bengal and Vidyasagar University, Midnapore, India
*Corresponding Author: Asit Kumar Chakraborty, Associate Professor of Biochemistry, Department of Biotechnology and Biochemistry, Oriental Institute of Science and Technology, West Bengal and Vidyasagar University, Midnapore, India.
Received: June 25, 2020; Published: September 17, 2020
Corona virus ORF1ab polyprotein-derived Nsp7 and Nsp8 are small proteins of 83aa and 198aa whose functions remain elusive as replication factors of Nsp12 RNA-dependent RNA polymerase. Using multi-alignment approaches we found such RNA binding proteins might have rRNA methyltransferase activities resembling Escherichia coli RlmB and RlmH like enzymes. Phylogenetic analysis suggested Nsp7 was cryptic MTase enzyme as compared to other methyltransferases but Nsp8 could be a vital methylating enzyme with similarity to S30 transposase. Moreover, Nsp8 has weak similarity to S2 ribosomal protein and L16 ribosomal proteins and Nsp7 to S8 ribosomal protein. We surprised to describe that Nsp7/8, Nsp9/10, Nsp13-16 and Nsp2 all have similarities to different ribosomal proteins (< 25%) which were also small RNA-binding proteins. We postulated both orf1a (4405aa) and ORF1ab (7096aa) large proteins act as rRNAs sequesters affecting ribosome turnover. Thus, methylation is a preference mechanism of Corona virus pathogenesis whereas COXI and COXII host mitochondrial enzymes synthesis may be affected causing low ATP synthesis followed by platelets aggregation and blood clotting in the lungs, heart and brain. Other words, we demonstrated new Corona virus targets that were never explored. Never-the-less the patients who were dying have weak immune-system and maximum load of virus occurred leading to coma and death but in maximum young patients the Corona virus was cleared by immune-system before the viruses could spread into other organs and the patients were recovered within 3 - 4 weeks.
Keywords: Nsp7 and Nsp8; Nsp Methyltransferase; Corona Virus Polyprotein; Clustal-Omega Software; Ribosomal Proteins Homologies
Citation: Asit Kumar Chakraborty. “Corona Virus ORF1ab-Derived Nsp7 and Nsp8 Small Non-Structural Proteins Including Previously Published Nsp9/10/13/16 Share Homologies to the Ribosomal Proteins as Well as rRNA Methyltransferases and Inhibit Host Protein Synthesis".Acta Scientific Medical Sciences 4.10 (2020): 22-28.
Copyright: © 2020 Asit Kumar Chakraborty. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.