title: Mutational analysis of the functional sites in porcine reproductive and respiratory syndrome virus non-structural protein 10.
abstract: Porcine reproductive and respiratory syndrome virus (PRRSV) is prevalent throughout the world and has caused major economic losses to the pig industry. Arterivirus non-structural protein 10 (nsp10) is a superfamily 1 helicase participating in multiple processes of virus replication. PRRSV nsp10, however, has not yet been well characterized. In this study, a series of nsp10 mutants were constructed and analysed for functional sites of different enzymic activities. We found that nsp10 could bind both ssDNA and dsDNA, and this binding activity could be inactivated by mutations at Cys25 and His32. These two mutations also abolished unwinding activity without affecting ATPase activity. In addition, substitution of Ala227 by Ser eliminated helicase activity, whilst substitution by Val enhanced unwinding activity. Taken together, our results showed that Cys25 and His32 in PRRSV nsp10 were critical for nucleic acid binding and unwinding, and that Ala227 played an important role in helicase activity.
authors.affiliation: Key Laboratory of Veterinary Diagnostic Products, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, PR China.|State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, PR China.
authors.forename: Yumeng
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Veterinary Diagnostic Products, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, PR China.|State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, PR China.
authors.forename: Huan
authors.initials: H
authors.lastname: Li
authors.affiliation: Key Laboratory of Veterinary Diagnostic Products, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, PR China.|State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, PR China.
authors.forename: Guiqing
authors.initials: G
authors.lastname: Peng
authors.affiliation: Key Laboratory of Veterinary Diagnostic Products, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, PR China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Veterinary Diagnostic Products, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, PR China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Gao
authors.affiliation: Key Laboratory of Veterinary Diagnostic Products, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, PR China.|State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, PR China.
authors.forename: Shaobo
authors.initials: S
authors.lastname: Xiao
authors.affiliation: Key Laboratory of Veterinary Diagnostic Products, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, PR China.|State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, PR China.
authors.forename: Shengbo
authors.initials: S
authors.lastname: Cao
authors.affiliation: Key Laboratory of Veterinary Diagnostic Products, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, PR China.|State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, PR China.
authors.forename: Huanchun
authors.initials: H
authors.lastname: Chen
authors.affiliation: Key Laboratory of Veterinary Diagnostic Products, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, PR China.|State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, PR China.
authors.forename: Yunfeng
authors.initials: Y
authors.lastname: Song
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D001665:Binding Sites; D015967:Gene Expression Regulation, Viral / Q000502:physiology; D008969:Molecular Sequence Data; D009154:Mutation; D019316:Porcine respiratory and reproductive syndrome virus / Q000235:genetics / Q000378:metabolism*; D017361:Viral Nonstructural Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D017361:Viral Nonstructural Proteins