title: Two adjacent mutations on the dimer interface of SARS coronavirus 3C-like protease cause different conformational changes in crystal structure.
abstract: The 3C-like protease of SARS coronavirus (SARS-CoV 3CL(pro)) is vital for SARS-CoV replication and is a promising drug target. It has been extensively proved that only the dimeric enzyme is active. Here we discovered that two adjacent mutations (Ser139_Ala and Phe140_Ala) on the dimer interface resulted in completely different crystal structures of the enzyme, demonstrating the distinct roles of these two residues in maintaining the active conformation of SARS-CoV 3CL(pro). S139A is a monomer that is structurally similar to the two reported monomers G11A and R298A. However, this mutant still retains a small fraction of dimer in solution, which might account for its remaining activity. F140A is a dimer with the most collapsed active pocket discovered so far, well-reflecting the stabilizing role of this residue. Moreover, a plausible dimerization mechanism was also deduced from structural analysis. Our work is expected to provide insight on the dimerization-function relationship of SARS-CoV 3CL(pro).
authors.affiliation: Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zuchongzhi Road, Pudong, Shanghai 201203, China.
authors.forename: Tiancen
authors.initials: T
authors.lastname: Hu
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhang
authors.forename: Lianwei
authors.initials: L
authors.lastname: Li
authors.forename: Kuifeng
authors.initials: K
authors.lastname: Wang
authors.forename: Shuai
authors.initials: S
authors.lastname: Chen
authors.forename: Jing
authors.initials: J
authors.lastname: Chen
authors.forename: Jianping
authors.initials: J
authors.lastname: Ding
authors.forename: Hualiang
authors.initials: H
authors.lastname: Jiang
authors.forename: Xu
authors.initials: X
authors.lastname: Shen
mesh_terms: D000086782:Coronavirus 3C Proteases; D003546:Cysteine Endopeptidases / Q000737:chemistry* / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D019281:Dimerization; D008958:Models, Molecular; D009154:Mutation; D017434:Protein Structure, Tertiary / Q000235:genetics; D045473:Severe acute respiratory syndrome-related coronavirus / Q000201:enzymology* / Q000235:genetics*; D013329:Structure-Activity Relationship; D014764:Viral Proteins / Q000737:chemistry* / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism
chemical_list: D014764:Viral Proteins; D003546:Cysteine Endopeptidases; D000086782:Coronavirus 3C Proteases