2.1. Study proteins
This article studied the 1ab polyprotein of SARS-CoV-2, SARS-CoV, and BatCoV RaTG13 . Also, the structural and accessory proteins found in SARS-CoV-2 and BatCoV RaTG13 were studied including the spike protein (S), orf3, envelope protein (E), membrane protein (M), orf6, orf7a, orf7b, orf8, and ncucleocapsid protein (N) (Table.2). The amino acid sequences were obtained from the National Center for Biotechnology Information (NCBI) site (https://www.ncbi.nlm.nih.gov/protein) (Table 1).