Structure and Function of Picornavirus Proteinases

摘要: This chapter summarizes the implications of three-dimensional structures on proteolytic mechanisms, substrate specificities, and functions proteinases in infected cells. The picornaviral polyproteins can be divided into three regions, designated P1, P2, P3. These correspond to N-terminal capsid protein precursor (P1, containing four proteins 1A-1D), middle polyprotein nonstructural (P2, 2A-2C), most C-terminal segment (P3, 3A-3D). In cardio- aphthoviruses, a known as leader precedes P1. hepato- parechoviruses encode only single enzyme are therefore proteolytically simplest picornaviruses. During replication picornavirus, physiology ultrastructure cells drastically modified. Thus, cellular RNA synthesis well trafficking inhibited. discusses crystal terms their mechanisms action specificities how have evolved able carry out specific roles respective viruses. Like Streptomyces griseus protease B (SGPB) 3C proteinases, HRV2 2Apro comprises two subdomains, built up by β-strands found chymotrypsin.