– The coronaviral proteases, papain-like protease (PLpro) and 3C-like protease (3CLpro), are attractive antiviral drug targets because they are essential for coronaviral replication. Although the primary function of PLpro and 3CLpro are to process the viral polyprotein in a coordinated manner, PLpro has the additional function of stripping ubiquitin and ISG15 from host-cell proteins to aid coronaviruses in their evasion of the host innate immune responses. SARS PLpro/papain-like protease Protein (His) is expressed in E. coli expression system with C-His tag. The predicted molecular weight is 36.91 kDa and the accession number is AAX16193.1.