PATHOGENICITY FACTORS AND GENOMIC ARCHITECTURE OF SARS-COV-2: A CRITICAL REVIEW

The flare-up of COVID-19 during December 2019 has evoked a hazard with respect to its worldwide spread and has become a genuine global concern. It is a severe infection that has circulated to more than 215 nations across the globe. As of July 31, 2020, an aggregate of 17,752,692 globally affirmed cases with 682,409 deaths have been reported. In the interim, several researchers have discovered that the disease is caused by the novel coronavirus SARS-CoV-2, which is identical to SARS-CoV and MERS-CoV. SARS-CoV-2 belongs to the Betacoronavirus genus and has strong molecular affiliations with that of SARS-CoV. It is not quite same as other related coronaviruses due to various RNA modifications or mutations in its epi-transcriptome. It is an enveloped, crowned, spherical RNA virus with a large mysterious genome (~30kb) that contains several structural and non-structural proteins with a variable number of ORFs present in between the conserved genes. It binds to the human receptor ACE2 with the help of its Spike (S) protein, and causes infection in humans. It is reported to exhibit a unique replication strategy where it produces several small sub-genomic RNAs for the synthesis and release of new virions within and from hosts for maintaining its lineage. This review provides a better understanding of the structure, phylogeny, mutation, genomics and pathogenesis patterns of SARS-CoV-2, which will help in planning appropriate immunization for treatment of this contagious and highly progressive infectious pathogen.