Cysteine protease that plays several role during infection including processing of the structural polyprotein or inhibition of the host immune response. Catalyzes the maturation of the pp220 and pp62 polyprotein precursors into core-shell proteins. Plays a role in the disruption of host pyroptosis via specific cleavage of gasdermin D/GSDMD. In addition, strongly decreases the host cGAS-STING signaling by targeting IKBKE via its enzymatic activity. Impairs also host FOXJ1-mediated antiviral effect via degradation of FOXJ1