The ongoing outbreak of Coronavirus Disease 2019(COVID-19)has become a global public health emergency.SARScoronavirus-2(SARS-CoV-2),the causative pathogen of COVID-19,is a positive-sense single-stranded RNA virus belo...The ongoing outbreak of Coronavirus Disease 2019(COVID-19)has become a global public health emergency.SARScoronavirus-2(SARS-CoV-2),the causative pathogen of COVID-19,is a positive-sense single-stranded RNA virus belonging to the family Coronaviridae.For RNA viruses,virus-encoded RNA helicases have long been recognized to play pivotal roles during viral life cycles by facilitating the correct folding and replication of viral RNAs.Here,our studies show that SARS-CoV-2-encoded nonstructural protein 13(nsp13)possesses the nucleoside triphosphate hydrolase(NTPase)and RNA helicase activities that can hydrolyze all types of NTPs and unwind RNA helices dependently of the presence of NTP,and further characterize the biochemical characteristics of these two enzymatic activities associated with SARS-CoV-2 nsp13.Moreover,we found that some bismuth salts could effectively inhibit both the NTPase and RNA helicase activities of SARS-CoV-2 nsp13 in a dose-dependent manner.Thus,our findings demonstrate the NTPase and helicase activities of SARS-CoV-2 nsp13,which may play an important role in SARS-CoV-2 replication and serve as a target for antivirals.展开更多
Nucleoside triphosphate hydrolase （NTPase） is a multifunctional enzymatic family widely existing in vivo. They can hydrolyze NTP to NMP or dNTP to dNMP to produce energy. In this article, the structure of Toxoplasma...Nucleoside triphosphate hydrolase （NTPase） is a multifunctional enzymatic family widely existing in vivo. They can hydrolyze NTP to NMP or dNTP to dNMP to produce energy. In this article, the structure of Toxoplasma gondii NTPase is analyzed. The research progress in NT- Pase of Toxoplasrna gondii, Trypanosoma cruzi, Sarcocystis neurona and Neospora caninum was briefly reviewed.展开更多
RNA-remodeling proteins,including RNA helicases and chaperones,play vital roles in the remodeling of structured RNAs.During viral replication,viruses require RNA-remodeling proteins to facilitate proper folding and/or...RNA-remodeling proteins,including RNA helicases and chaperones,play vital roles in the remodeling of structured RNAs.During viral replication,viruses require RNA-remodeling proteins to facilitate proper folding and/or re-folding the viral RNA elements.Coxsackieviruses B3(CVB3)and Coxsackieviruses B5(CVB5),belonging to the genus Enterovirus in the family Picornaviridae,have been reported to cause various infectious diseases such as hand-foot-and-mouth disease,aseptic meningitis,and viral myocarditis.However,little is known about whether CVB3 and CVB5 encode any RNA remodeling proteins.In this study,we showed that 2C proteins of CVB3 and CVB5 contained the conserved SF3 helicase A,B,and C motifs,and functioned not only as RNA helicase that unwound RNA helix bidirectionally in an NTP-dependent manner,but also as RNA chaperone that remodeled structured RNAs and facilitated RNA strand annealing independently of NTP.In addition,we determined that the NTPase activity and RNA helicase activity of 2C proteins of CVB3 and CVB5 were dependent on the presence of divalent metallic ions.Our findings demonstrate that 2C proteins of CVBs possess RNA-remodeling activity and underline the functional importance of 2C protein in the life cycle of CVBs.展开更多
基金supported by the Strategic Priority Research Program of CAS(XDB29010300 to X.Z.)National Natural Science Foundation of China(81873964 to Y.Q.,31800140 to J.M.and 31670161 to X.Z.)+1 种基金National Science and Technology Major Project(2018ZX10101004 to X.Z.)the Science and Technology Development Fund,Macao SAR(0007/2020/A to R.W)。
文摘The ongoing outbreak of Coronavirus Disease 2019(COVID-19)has become a global public health emergency.SARScoronavirus-2(SARS-CoV-2),the causative pathogen of COVID-19,is a positive-sense single-stranded RNA virus belonging to the family Coronaviridae.For RNA viruses,virus-encoded RNA helicases have long been recognized to play pivotal roles during viral life cycles by facilitating the correct folding and replication of viral RNAs.Here,our studies show that SARS-CoV-2-encoded nonstructural protein 13(nsp13)possesses the nucleoside triphosphate hydrolase(NTPase)and RNA helicase activities that can hydrolyze all types of NTPs and unwind RNA helices dependently of the presence of NTP,and further characterize the biochemical characteristics of these two enzymatic activities associated with SARS-CoV-2 nsp13.Moreover,we found that some bismuth salts could effectively inhibit both the NTPase and RNA helicase activities of SARS-CoV-2 nsp13 in a dose-dependent manner.Thus,our findings demonstrate the NTPase and helicase activities of SARS-CoV-2 nsp13,which may play an important role in SARS-CoV-2 replication and serve as a target for antivirals.
基金supported by the grants from the National Special Research Fund for Public Welfare (Agriculture) of China (200803017 and 200903036-06)
文摘Nucleoside triphosphate hydrolase （NTPase） is a multifunctional enzymatic family widely existing in vivo. They can hydrolyze NTP to NMP or dNTP to dNMP to produce energy. In this article, the structure of Toxoplasma gondii NTPase is analyzed. The research progress in NT- Pase of Toxoplasrna gondii, Trypanosoma cruzi, Sarcocystis neurona and Neospora caninum was briefly reviewed.
基金supported by the National Natural Science Foundation of China (82002155 to T.S., and U21A20423 and 31670161 to X.Z.)
文摘RNA-remodeling proteins,including RNA helicases and chaperones,play vital roles in the remodeling of structured RNAs.During viral replication,viruses require RNA-remodeling proteins to facilitate proper folding and/or re-folding the viral RNA elements.Coxsackieviruses B3(CVB3)and Coxsackieviruses B5(CVB5),belonging to the genus Enterovirus in the family Picornaviridae,have been reported to cause various infectious diseases such as hand-foot-and-mouth disease,aseptic meningitis,and viral myocarditis.However,little is known about whether CVB3 and CVB5 encode any RNA remodeling proteins.In this study,we showed that 2C proteins of CVB3 and CVB5 contained the conserved SF3 helicase A,B,and C motifs,and functioned not only as RNA helicase that unwound RNA helix bidirectionally in an NTP-dependent manner,but also as RNA chaperone that remodeled structured RNAs and facilitated RNA strand annealing independently of NTP.In addition,we determined that the NTPase activity and RNA helicase activity of 2C proteins of CVB3 and CVB5 were dependent on the presence of divalent metallic ions.Our findings demonstrate that 2C proteins of CVBs possess RNA-remodeling activity and underline the functional importance of 2C protein in the life cycle of CVBs.
文摘柞蚕传染性软腐病病毒是从感染吐白水软化病的柞蚕体内分离的一株小RNA病毒,属于软腐病病毒属(Iflavirus),含解旋酶结构域的2C蛋白是该病毒的功能蛋白质之一。以感染柞蚕软腐病病毒的柞蚕蛹c DNA为模板,PCR获得2C蛋白的编码基因,并利用Bac-to-Bac表达系统构建重组杆粒p Fast Bac-Dual-GFP-Hel 2C,在昆虫细胞Sf9中表达了该病毒的2C蛋白。对重组2C蛋白的三磷酸核苷水解酶(NTPase)活性和解旋酶活性进行检测的结果显示:重组2C蛋白具有NTPase活性,能够水解4种NTP,并且具有解旋酶活性,能够解旋3'端至5'端方向单链突出的双链DNA。初步推测2C蛋白在柞蚕传染性软腐病病毒复制中发挥水解三磷酸核苷和解旋DNA链的作用。
