Insights into the Structure, Replication, and Pathogenesis of the Severe Acute Respiratory Syndrome Coronavirus 2

Background: The recent coronavirus disease-19 (COVID-19) emergence worldwide associated with pneumonia-like symptoms poses a great threat to human health. This article highlights the genomic structure, viral replication, classification of structural and non-structural proteins according to their primary function, and viral pathogenesis. Search Methodology: Literature of this review was collected from different databases like PubMed, Embase, Scopus, Medline, and Web of Science by using following keywords COVID-19, Genomic structure, Non-structural proteins, Viral replication, Viral pathogenesis. Results: Severe acute respiratory syndrome-2 (SARS-CoV-2) is single-stranded RNA enveloped virus containing less conserved matrix (M), nucleocapsid (N), and spike (S) proteins involved in viral entry, virion assembly, nucleocapsid formation and defining coronavirus shape. S protein and Angiotensin-converting enzyme 2(ACE-2) receptor binding facilitates virus entry and membrane fusion. M and N proteins are expressed together to form mature virion assembly, transported in secretory vesicles for release towards the cell membrane. SARS-CoV-2 pathogenesis is complex involving pathological pathways such as cytokines dysregulation, cytopathic effects, innate immune response deficiencies, ACE-2 down regulation and direct immune cell evasion, causing severe injury to lung tissues. Conclusion: A broad understanding of replicase transcriptase complex (RTC) intricacies in viral replication and the role of different accessory and structural proteins in viral pathogenesis enhances the ability to develop therapeutic tools with reducing disease potential.