title: Identification and characterization of Iflavirus 3C-like protease processing activities.
abstract: Viral replication and capsid assembly in the viruses in the order Picornavirales requires polyprotein proteolytic processing by 3C or 3C-like (3CL) proteases. We identified and characterized the 3CL protease of Ectropis obliqua virus (EoV) of the newly established family Iflaviridae (order Picornavirales). The bacterially expressed EoV 3CL protease domain autocatalytically released itself from larger precursors by proteolytic cleavage, and cleavage sites were determined via N-terminal sequencing of the cleavage products. This protease also mediated trans-proteolytic activity and cleaved the polyprotein at the same specific positions. Moreover, we determined the critical catalytic residues (H2261, D2299, C2383) for the protease activity, and characterized the biochemical properties of EoV 3CL and its responses to various protease inhibitors. Our work is the first study to identify an iflaviral 3CL protease and further characterize it in detail and should foster our understanding of EoV and other iflaviruses.
authors.affiliation: The State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, Hubei 430072, China.
authors.forename: Shan
authors.initials: S
authors.lastname: Ye
authors.forename: Hongjie
authors.initials: H
authors.lastname: Xia
authors.forename: Chen
authors.initials: C
authors.lastname: Dong
authors.forename: Zhenyun
authors.initials: Z
authors.lastname: Cheng
authors.forename: Xiaoling
authors.initials: X
authors.lastname: Xia
authors.forename: Jiamin
authors.initials: J
authors.lastname: Zhang
authors.forename: Xi
authors.initials: X
authors.lastname: Zhou
authors.forename: Yuanyang
authors.initials: Y
authors.lastname: Hu
mesh_terms: D000086042:3C Viral Proteases; D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D002384:Catalysis; D003546:Cysteine Endopeptidases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D011499:Protein Processing, Post-Translational; D012328:RNA Viruses / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics; D016415:Sequence Alignment; D013379:Substrate Specificity; D014764:Viral Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
chemical_list: D014764:Viral Proteins; D003546:Cysteine Endopeptidases; D000086042:3C Viral Proteases