The coronavirus family is named for the large spike protein molecules found
on the pathogen exterior, which give the virus a crown-like appearance, the coronavirus
genome is the biggest among RNA viruses. There are about seven viruses capable of
infecting humans: in the alpha genus, there are 229E and NL63, and in the beta genus,
there are OC-43, HKU1, MERS-CoV, SARS-CoV, and SARS-CoV-2. The severe
acute respiratory syndrome coronavirus (SARS-CoV) is a positive-stranded RNA virus.
In humans, the virus is transmitted through respiratory tract droplets or discharges from
diseased persons. The reservoir hosts for MERS-CoV are camels, while those for
SARS-CoV are most likely bats. SARS-CoV-2 infecting a snake may have been
transmitted by zoonotic transmission in a palm civet. The Chinese viruses SARS-Co-
-2 and SARS-CoV have many things in common, including contact with wild
animals.However, both SARS-CoV-2 and MERS-CoV have the ability to persist and
spread the illness even when the infected individuals are untreated. SARS-S1 CoV-2's
components of the spike proteins have 75% structural commonality with SARS-like
CoVs in bats and SARS-CoV. According to genetic comparisons, the latest
investigations have proven that SARS-CoV-2 targets angiotensin-converting enzyme
type-2 (ACE-2) in humans. However, SARS-CoV-2 possesses an identical receptorbinding domain (RBD) pattern to SARS-CoV, with differences in amino acid
sequences at certain vital positions. The RBD is also found in the C-domain S1 component of MERS-CoV's S protein (Spike). Conversely, in contrast to SARS-CoV,
MERS-CoV uses a dipeptidyl-peptidase-4 (DPP-4) helix as its binding site. Similarly,
MERS-RBD coronaviruses (CoVs) have an extra subdomain that functions as the
receptor-binding motif (RBM).
Keywords: SARS-CoV, SARS-CoV-2, MERS-CoV, Mutations, Emergence, Phylogeny, Intermediate host, Conserved region.
