SARS-CoV-2: Insight in genome structure, pathogenesis and viral receptor binding analysis - An updated review

Abstract

The novel coronavirus disease (COVID-19) a global pandemic outbreak is an emerging new virus accountable for respiratory illness caused by SARS-CoV-2, originated in Wuhan city, Hubei province China, urgently calls to adopt prevention and intervention strategies. Several viral epidemics such as severe acute respiratory syndrome coronavirus (SARS-CoV) in 2002 to 2003 and H1N1 influenza in 2009 were reported since last two decades. Moreover, the Saudi Arabia was the epicenter for Middle East respiratory syndrome coronavirus (MERS-CoV) in 2012. The CoVs are large family with single-stranded RNA viruses (+ssRNA). Genome sequence of 2019-nCoV, shows relatively different homology from other coronavirus subtypes, categorized in betacoronavirus and possibly found from strain of bats. The COVID-19 composed of exposed densely glycosylated spike protein (S) determines virus binding and infiltrate into host cells as well as initiate protective host immune response. Recently published reviews on the emerging SARS-CoV-2 have mainly focused on its structure, development of the outbreak, relevant precautions and management trials. Currently, there is an urgency of pharmacological intervention to combat this deadly infectious disease. Elucidation of molecular mechanism of COVID-19 becomes necessary. Based on the current literature and understanding, the aim of this review is to provide current genome structure, etiology, clinical prognosis as well as to explore the viral receptor binding together functional insight of SARS-CoV-2 infection (COVID-19) with treatment and preventive measures.

Keywords: COVID-19; Coronavirus; MERS-CoV; SARS-CoV-2; Vaccine.

Graphical abstract

Fig. 1

The timeline for emerging highly pathogenic viruses and the proposed Disease X.

Fig. 2

Schematic representation of RNA genome and Structure of SARS- CoV 2. respectively (A.) Singe stranded RNA genome of SARS-CoV2 (~30 kb in length) showing with different components of genome (B.) Structure of SARS- CoV 2 is constituted of different elements such as Spike (S1 and S2), Nucleocapsid, membrane, envelope, ssRNA.

Fig.3

Proposed mechanisms of SARS-CoV-2 entry into the cells. Viral Receptor binding occurred through a densely S-spike protein present on outer surface of virion, responsible entry of genetic material (RNA) , which is then mRNA and host machinery starts translate into protein . The cell is then killed and releases into extracellular milieu after entering the virus into the cell.

Fig. 4

Transmission Cycle of SARS-CoV2.

Fig. 5

Clinical presentation of patients with COVID19.

Fig. 6

Preventive measures.