Unusual substructure conformations observed in crystal structures of a dicistrovirus RNA-dependent RNA polymerase suggest contribution of the N-terminal extension in proper folding

作     者：Xiang Fang Guoliang Lu Yanchun Deng Sa Yang Chunsheng Hou Peng Gong Xiang Fang;Guoliang Lu;Yanchun Deng;Sa Yang;Chunsheng Hou;Peng Gong

作者机构：Key Laboratory of Special Pathogens and BiosafetyWuhan Institute of VirologyChinese Academy of SciencesWuhan430207China Institute of Bast Fiber CropsChinese Academy of Agricultural SciencesChangsha410205China University of Chinese Academy of SciencesBeijing100049China Institute of Apicultural ResearchChinese Academy of Agricultural SciencesBeijing100193China Hubei Jiangxia LaboratoryWuhan430207China 

出 版 物：《Virologica Sinica》 (中国病毒学（英文版）)

年 卷 期：2023年第38卷第4期

页      面：531-540页

核心收录：

学科分类：0710[理学-生物学] 1007[医学-药学(可授医学、理学学位)] 1004[医学-公共卫生与预防医学(可授医学、理学学位)] 1002[医学-临床医学] 1001[医学-基础医学(可授医学、理学学位)] 09[农学] 0904[农学-植物保护] 090401[农学-植物病理学] 

基　　金：supported by the National Natural Science Foundation of China (31802147 to G.L.,31572471,31811530276 to C.H.) National Key Research and Development Program of China (2018YFA0507200 to P.G.and G.L.) the Agricultural Science and Technology Innovation Program (CAAS-ASTIP-2023-IBFC to C.H.) the Creative Research Group Program of Natural Science Foundation of Hubei Province (2022CFA021 to P.G.) the Central Public-Interest Scientific Institution Basal Research Fund (Y2021YJ25 to C.H.) Key Biosafety Science and Technology Program of Hubei Jiangxia Laboratory (JXBS001 to P.G.) 

主　　题：Israeli acute paralysis virus(IAPV) Poliovirus RNA-dependent RNA polymerase(RdRP) Crystal structure Catalytic motif 

摘      要：The Dicistroviridae is a virus family that includes many insect *** viruses contain a positive-sense RNA genome that is replicated by the virally encoded RNA-dependent RNA polymerase(RdRP)also named 3D^(pol).Compared with the Picornaviridae RdRPs such as poliovirus(PV)3D^(pol),the Dicistroviridae representative Israeli acute paralysis virus(IAPV)3D^(pol) has an additional N-terminal extension(NE)region that is about 40-residue in *** date,both the structure and catalytic mechanism of the Dicistroviridae RdRP have remain *** we reported crystal structures of two truncated forms of IAPV 3D^(pol),namelyΔ85 andΔ40,both missing the NE region,and the 3D^(pol) protein in these structures exhibited three conformational *** palm and thumb domains of these IAPV 3D^(pol) structures are largely consistent with those of the PV 3D^(pol) ***,in all structures,the RdRP fingers domain is partially disordered,while different conformations of RdRP substructures and interactions between them are also *** particular,a large-scale conformational change occurred in the motif B-middle finger region in one protein chain of theΔ40 structure,while a previously documented alternative conformation of motif A was observed in all IAPV *** experimental data on one hand show intrinsic conformational variances of RdRP substructures,and on the other hand suggest possible contribution of the NE region in proper RdRP folding in IAPV.