– The viral main proteinase (M pro , also called 3CL pro ), which controls the activities of the coronavirus replication complex. It functions as a cysteine protease engaging in the proteolytic cleavage of the viral precursor polyprotein to a series of functional proteins required for coronavirus replication and is considered as an appealing target for designing anti-SARS agents. 3CLpro/3C-like Protease Protein, SARS-CoV-2, Recombinant (His) is expressed in E. coli expression system with N-6xHis tag. The predicted molecular weight is 33 KDa and the accession number is P0DTC1.