title: Identification and characterization of RNA duplex unwinding and ATPase activities of an alphatetravirus superfamily 1 helicase.
abstract: Dendrolimus punctatus tetravirus (DpTV) belongs to the genus omegatetravirus of the Alphatetraviridae family. Sequence analysis predicts that DpTV replicase contains a putative helicase domain (Hel). However, the helicase activity in alphatetraviruses has never been formally determined. In this study, we determined that DpTV Hel is a functional RNA helicase belonging to superfamily-1 helicase with 5'-3' dsRNA unwinding directionality. Further characterization determined the length requirement of the 5' single-stranded tail on the RNA template and the optimal reaction conditions for the unwinding activity of DpTV Hel. Moreover, DpTV Hel also contains NTPase activity. The ATPase activity of DpTV Hel could be significantly stimulated by dsRNA, and dsRNA could partially rescue the ATPase activity abolishment caused by mutations. Our study is the first to identify an alphatetravirus RNA helicase and further characterize its dsRNA unwinding and NTPase activities in detail and should foster our understanding of DpTV and other alphatetraviruses.
authors.affiliation: State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, Hubei 430072, China.
authors.forename: Qinrong
authors.initials: Q
authors.lastname: Wang
authors.forename: Yajuan
authors.initials: Y
authors.lastname: Han
authors.forename: Yang
authors.initials: Y
authors.lastname: Qiu
authors.forename: Shaoqiong
authors.initials: S
authors.lastname: Zhang
authors.forename: Fenfen
authors.initials: F
authors.lastname: Tang
authors.forename: Yan
authors.initials: Y
authors.lastname: Wang
authors.forename: Jiamin
authors.initials: J
authors.lastname: Zhang
authors.forename: Yuanyang
authors.initials: Y
authors.lastname: Hu
authors.forename: Xi
authors.initials: X
authors.lastname: Zhou
mesh_terms: D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D000818:Animals; D001483:Base Sequence; D007304:Insect Viruses / Q000201:enzymology* / Q000235:genetics; D007700:Kinetics; D008969:Molecular Sequence Data; D009036:Moths / Q000821:virology; D016297:Mutagenesis, Site-Directed; D043583:Nucleoside-Triphosphatase / Q000235:genetics / Q000378:metabolism; D012313:RNA / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D020365:RNA Helicases / Q000235:genetics / Q000378:metabolism*; D012328:RNA Viruses / Q000201:enzymology* / Q000235:genetics; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D061987:Sf9 Cells; D018411:Spodoptera; D013379:Substrate Specificity
chemical_list: D011994:Recombinant Proteins; D012313:RNA; D000251:Adenosine Triphosphatases; D043583:Nucleoside-Triphosphatase; D020365:RNA Helicases