Structural, molecular biology and the immunopathology of SARS-CoV-2: An
updated review
Abstract
Coronaviruses are a group of enveloped viruses with non-segmented,
single-stranded, and positive-sense RNA genomes. Human coronavirus
infection causes respiratory diseases with mild to severe outcomes. In
December 2019, a new outbreak of the novel coronavirus disease 2019
(COVID-19) emerged in Wuhan, China and spread around the world. Genomic
analysis revealed that severe acute respiratory syndrome coronavirus
(SARS-CoV-2) is phylogenetically related to SARS-like bat viruses. The
intermediate source of origin of SARS-CoV-2 and its transfer to humans
is not known; however, it acquired efficient human-to-human
transmissibility while retaining human pathogenicity. Spike protein of
SARS-CoV-2 has the potential furin-like cleavage site may play a
significant role in virus entry. Receptor binding domain (RBD) of
SARS-CoV-2 attaches with angiotensin-converting enzyme -2 (ACE2) of
epithelial cells. The SARS-CoV-2 genome encodes four major structural
proteins: the spike (S) protein, nucleocapsid (N) protein, membrane (M)
protein, and the envelope (E) protein are involved in assembly, budding,
envelope formation, and pathogenesis. Notably, E protein act as
viroporin and there is no mutation found on E protein among SARS-CoV-2
strains. At present, the case fatality rate is estimated to range from 6
to 7%. COVID-19 is now a public health emergency of international
concern. There is no clinically approved antiviral drug or vaccine
available against COVID-19. This review summarized the latest
information on the structural and molecular biology infectivity, host
immune response and molecular immunopathology of the SARS-CoV-2.