Table 1.

Residue Variation in the Active site of Coronavirus.

Residue Position	Subsite	Residue in SARS-CoV-2 Mpro	Residue Variety
49	S2	Met	Leu, Ala, Met, Tyr, Ser, Phe, Asn, Thr
50	S2	Leu	Val, Thr, Asn, Gln, Lys, His, Ser, Arg, Met, Ala, Leu
190	S4	Thr	Thr, Val, Lys, Asn, Cys, Ile, Arg, Ser, Leu
191	S4	Ala	Val, Ile, Pro, Phe, His, Tyr, Ser, Met, Leu, Ala
193	S4	Val	Lys, Asn, Gln, Ile, Val, Ala, Leu, Met, Phe, Arg, His, Ser