SARS-Cov2 and Crispr-Cas Gene Assignment – Cracking the Code for SARS-Cov2 and the Discovery of

Cracking the Code for SARS-Cov2 and the Discovery of CRISPR-Cas Gene

Editing Mechanism

SARS-Cov2

1.) Describe the morphological structure of SARS-Cov2 virus.

– According to studies through the use of Electron microscopy, the

structure of SARS-CoV-2 is speculated to be similar to that of

SARS-CoV with a virion size ranging from 70 to 90 nm (Kumar et al.

2020). The SARS-CoV-2 virus is also found to have surface viral

proteins, namely, the spike glycoprotein (S) which mediates interaction

with cell surface receptor ACE2, as well as, viral membrane (M) and

envelope (E) viral proteins that are embedded in host

membrane-derived lipid bilayer encapsulating the helical nucleocapsid

comprising viral RNA (Kumar et al. 2020).

2.) In a complete statement, state the size of the SARS-Cov2 genome.

– The size of the SARS-CoV-2 genome is found to be in the range of 26

up to 32 kb (kilobases) and is comprise of 6 to 11 open reading frames

(ORFs) encoding 9680 amino acid polyproteins (Kumar et al. 2020).

3.) How does the SARS-Cov2 infect (enter) its host cell and how is it

replicated inside the host cell ?

– The SARS-CoV-2 virus, like SARS-CoV, enters into its host target cells

through the binding of spike protein, which exhibits 10-20 times

higher affinity than that of SARS-CoV, to the

angiotensin-converting enzyme 2 (ACE2) receptor for

internalization and then the use of transmembrane serine proteases

(TMPRSS2) for S protein priming (Kumar et al. 2020). This then

results in conformational changes in the spike protein that leads to the

fusion of the viral envelope (E) protein with the host cell membrane

following the entry via an endosomal pathway (Kumar et al. 2020). This

internalization or entry is followed by the release of the viral RNA

into the host9s cytoplasm where it will undergo translation and

generate replicase polyproteins ppla and pplb which is then further

cleaved by the virus9 encoded proteinases into small proteins.

Replication of coronavirus which involves ribosomal frame-shifting

during the translation process then proceeds (Kumar et al. 2020).

Through discontinuous transcription, the replication process then

generates both genomic and multiple copies of subgenomic RNA