2.2. Sequence alignment
The online sequence alignment service of The European Molecular Biology Open Software Suite (EMBOSS) was used to determine the protein similarity and identity percentages of the SARS-CoV-2, SARS-CoV, and RaTG13. The matrix of the sequence alignment was EBLOSUM62 and the gap and extend penalties were 14 and 4, respectively. The sequence alignment service of the EMBOSS is available at: https://www.bioinformatics.nl/cgi-bin/emboss/matcher.