Open AccessLaboratory diagnosis of SARS-CoV-2: an Update for Clinicians
Author(s) -
Imtiyaz Ahmad Bhat,
Zafar A. Shah,
Shariq Rashid Masoodi
Publication year - 2020
Publication title -
journal of medical sciences/journal of medical sciences (srinagar. online)
Language(s) - English
Resource type - Journals
eISSN - 2582-063X
pISSN - 0972-110X
DOI - 10.33883/jms.v23i2.766
Subject(s) - orfs , coronavirus , genome , biology , rna , virology , viral envelope , genetics , gene , glycoprotein , nucleoprotein , viral matrix protein , open reading frame , peptide sequence , medicine , covid-19 , disease , pathology , infectious disease (medical specialty)
SARS-CoV-2 belongs to the genera Beta coronavirus with a spherical or pleomorphic virus enveloped particles. The SARS-CoV-2 has sequence homology with severe acute respiratory syndrome-related coronaviruses (SARSr-CoV) and acts on ACE2 (Angiotensin Converting Enzyme 2) receptor by using its spike proteins. The latter are primed by the enzyme, TMPRSS2 protease to complete this process for its entry into the cells [1-3]. The SARSr-CoV has a single-stranded positive-sense ribonucleic acid (RNA) as a genomic material associated with a nucleoprotein within a capsid comprised of matrix proteins. The envelope bears a club-shaped glycoprotein projection containing haemagglutinin-esterase proteins (HE) also. The size of Coronaviruses genome is around (26.4-31.7Kb), which is one of the largest genomes in RNA known viruses and bears the GC content of approximately 32 to 43%. The viral genome contains distinctive features including a unique N terminal fragment within the spike proteins. The genome contains a variable number of ORF (6–11) between the various conserved genes (ORF1ab, spike, envelope, membrane and nucleocapsid [4]. Two third of the SARS-CoV-2 viral RNA is located in the ORF (ORF1a/b) and synthesise polypeptides pp1a and pp1a, and 16 non-structural proteins (NSP) are encoded by these ORFs, and the remaining accessory proteins are translated by other ORFs. The genome that encodes essential structural proteins which are important in the pathogenicity of SARS-CoV-2 like spike (S) glycoprotein, small envelope (E) protein, matrix (M) protein, and nucleocapsid (N) protein are translated by the rest of the viral genome [5].