Table 2.

Comparison of amino acids at position 723 in the different strains of coronaviruses

Coronavirus strain	Amino acid at position 723	Predicted significance of the amino acid substitutions
SARS-CoV-2	Serine	Serine is believed to promote rigorousness to the polypeptide chain due to the steric effect and its capability to form H bonds. At the active site of enzymes, it may also act as a nucleophile (18).
Bat like SARS-CoV	Glycine
SARS-CoV	Glycine

SARS-CoV-2, Severe Acute Respiratory Coronavirus-2; SARS-CoV, Severe Acute Respiratory Coronavirus.