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Zhao B, Hu L, Kaundal S, Neetu N, Lee CH, Somoulay X, Sankaran B, Taylor GM, Dermody TS, Venkataram Prasad BV. Structure of orthoreovirus RNA chaperone σNS, a component of viral replication factories. Nat Commun 2024; 15:2460. [PMID: 38503747 PMCID: PMC10950856 DOI: 10.1038/s41467-024-46627-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Accepted: 02/29/2024] [Indexed: 03/21/2024] Open
Abstract
The mammalian orthoreovirus (reovirus) σNS protein is required for formation of replication compartments that support viral genome replication and capsid assembly. Despite its functional importance, a mechanistic understanding of σNS is lacking. We conducted structural and biochemical analyses of a σNS mutant that forms dimers instead of the higher-order oligomers formed by wildtype (WT) σNS. The crystal structure shows that dimers interact with each other using N-terminal arms to form a helical assembly resembling WT σNS filaments in complex with RNA observed using cryo-EM. The interior of the helical assembly is of appropriate diameter to bind RNA. The helical assembly is disrupted by bile acids, which bind to the same site as the N-terminal arm. This finding suggests that the N-terminal arm functions in conferring context-dependent oligomeric states of σNS, which is supported by the structure of σNS lacking an N-terminal arm. We further observed that σNS has RNA chaperone activity likely essential for presenting mRNA to the viral polymerase for genome replication. This activity is reduced by bile acids and abolished by N-terminal arm deletion, suggesting that the activity requires formation of σNS oligomers. Our studies provide structural and mechanistic insights into the function of σNS in reovirus replication.
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Affiliation(s)
- Boyang Zhao
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, USA
| | - Liya Hu
- Verna and Marrs Mclean Department of Biochemistry and Molecular Pharmacology, Baylor College of Medicine, Houston, TX, USA
| | - Soni Kaundal
- Verna and Marrs Mclean Department of Biochemistry and Molecular Pharmacology, Baylor College of Medicine, Houston, TX, USA
| | - Neetu Neetu
- Verna and Marrs Mclean Department of Biochemistry and Molecular Pharmacology, Baylor College of Medicine, Houston, TX, USA
| | - Christopher H Lee
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburg, PA, USA
- Institute of Infection, Inflammation, and Immunity, UPMC Children's Hospital of Pittsburgh, Pittsburg, PA, USA
| | - Xayathed Somoulay
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburg, PA, USA
- Institute of Infection, Inflammation, and Immunity, UPMC Children's Hospital of Pittsburgh, Pittsburg, PA, USA
| | - Banumathi Sankaran
- Berkeley Center for Structural Biology, Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley Laboratory, Berkeley, CA, USA
| | - Gwen M Taylor
- Institute of Infection, Inflammation, and Immunity, UPMC Children's Hospital of Pittsburgh, Pittsburg, PA, USA
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburg, PA, USA
| | - Terence S Dermody
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburg, PA, USA.
- Institute of Infection, Inflammation, and Immunity, UPMC Children's Hospital of Pittsburgh, Pittsburg, PA, USA.
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburg, PA, USA.
| | - B V Venkataram Prasad
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, USA.
- Verna and Marrs Mclean Department of Biochemistry and Molecular Pharmacology, Baylor College of Medicine, Houston, TX, USA.
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Zhao B, Hu L, Kuandal S, Neetu N, Lee C, Somoulay X, Sankaran B, Taylor GM, Dermody TS, Prasad BVV. Structure of Orthoreovirus RNA Chaperone σNS, a Component of Viral Replication Factories. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.31.551319. [PMID: 37577609 PMCID: PMC10418060 DOI: 10.1101/2023.07.31.551319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
The reovirus σNS RNA-binding protein is required for formation of intracellular compartments during viral infection that support viral genome replication and capsid assembly. Despite its functional importance, a mechanistic understanding of σNS is lacking. We conducted structural and biochemical analyses of an R6A mutant of σNS that forms dimers instead of the higher-order oligomers formed by wildtype (WT) σNS. The crystal structure of selenomethionine-substituted σNS-R6A reveals that the mutant protein forms a stable antiparallel dimer, with each subunit having a well-folded central core and a projecting N-terminal arm. The dimers interact with each other by inserting the N-terminal arms into a hydrophobic pocket of the neighboring dimers on either side to form a helical assembly that resembles filaments of WT σNS in complex with RNA observed using cryo-EM. The interior of the crystallographic helical assembly is positively charged and of appropriate diameter to bind RNA. The helical assembly is disrupted by bile acids, which bind to the same hydrophobic pocket as the N-terminal arm, as demonstrated in the crystal structure of σNS-R6A in complex with bile acid, suggesting that the N-terminal arm functions in conferring context-dependent oligomeric states of σNS. This idea is supported by the structure of σNS lacking the N-terminal arm. We discovered that σNS displays RNA helix destabilizing and annealing activities, likely essential for presenting mRNA to the viral RNA-dependent RNA polymerase for genome replication. The RNA chaperone activity is reduced by bile acids and abolished by N-terminal arm deletion, suggesting that the activity requires formation of σNS oligomers. Our studies provide structural and mechanistic insights into the function of σNS in reovirus replication.
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A Fijivirus Major Viroplasm Protein Shows RNA-Stimulated ATPase Activity by Adopting Pentameric and Hexameric Assemblies of Dimers. mBio 2023; 14:e0002323. [PMID: 36786587 PMCID: PMC10128069 DOI: 10.1128/mbio.00023-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023] Open
Abstract
Fijiviruses replicate and package their genomes within viroplasms in a process involving RNA-RNA and RNA-protein interactions. Here, we demonstrate that the 24 C-terminal residues (C-arm) of the P9-1 major viroplasm protein of the mal de Río Cuarto virus (MRCV) are required for its multimerization and the formation of viroplasm-like structures. Using an integrative structural approach, the C-arm was found to be dispensable for P9-1 dimer assembly but essential for the formation of pentamers and hexamers of dimers (decamers and dodecamers), which favored RNA binding. Although both P9-1 and P9-1ΔC-arm catalyzed ATP with similar activities, an RNA-stimulated ATPase activity was only detected in the full-length protein, indicating a C-arm-mediated interaction between the ATP catalytic site and the allosteric RNA binding sites in the (do)decameric assemblies. A stronger preference to bind phosphate moieties in the decamer was predicted, suggesting that the allosteric modulation of ATPase activity by RNA is favored in this structural conformation. Our work reveals the structural versatility of a fijivirus major viroplasm protein and provides clues to its mechanism of action. IMPORTANCE The mal de Río Cuarto virus (MRCV) causes an important maize disease in Argentina. MRCV replicates in several species of Gramineae plants and planthopper vectors. The viral factories, also called viroplasms, have been studied in detail in animal reovirids. This work reveals that a major viroplasm protein of MRCV forms previously unidentified structural arrangements and provides evidence that it may simultaneously adopt two distinct quaternary assemblies. Furthermore, our work uncovers an allosteric communication between the ATP and RNA binding sites that is favored in the multimeric arrangements. Our results contribute to the understanding of plant reovirids viroplasm structure and function and pave the way for the design of antiviral strategies for disease control.
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Liu Y, Chen J, Xie D, Song B, Hu D. First Report on Anti-TSWV Activities of Quinazolinone Derivatives Containing a Dithioacetal Moiety. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:12135-12142. [PMID: 34623814 DOI: 10.1021/acs.jafc.1c03171] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Tomato spotted wilt virus (TSWV) is a plant virus with strong infectivity and destructive power. Given the lack of effective control agents, TSWV causes significant economic damage to several vegetables and ornamental plants worldwide. In this study, we designed and synthesized a series of novel quinazolinone derivatives containing a dithioacetal moiety and evaluated their antiviral activity in vitro and in vivo against TSWV. Some candidate compounds showed good anti-TSWV activity. Compound 6n shows excellent anti-TSWV activity in vivo, and the EC50 value is 188 mg/L, which is notably better than that observed for ribavirin (642 mg/L), xiangcaoliusuobingmi (420 mg/L), and ningnanmycin (257 mg/L). In addition, compound 6n interacts with TSWV coat protein at sites ARG94 and ARG95 forming four π-alkyl interactions. Compound 6n (9.4 μM) shows a better binding affinity with TSWV coat protein than ribavirin (67.8 μM), xiangcaoliusuobingmi (33.8 μM), and ningnanmycin (24.3 μM). Therefore, compound 6n can serve as a lead compound for the discovery of new antiviral agents for the management of TSWV.
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Affiliation(s)
- Yuewen Liu
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, China
| | - Jixiang Chen
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, China
| | - Dandan Xie
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, China
| | - Baoan Song
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, China
| | - Deyu Hu
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, China
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Huang M, Yan Y, Wang L, Chen J, Liu T, Xie X, Li X. Research on the Interaction Mechanism Between α Mino-Phosphonate Derivative Q-R and Harpin-Binding Protein 1 in Tobacco ( Nicotiana tabacum) Plants. Front Microbiol 2021; 12:621875. [PMID: 33868188 PMCID: PMC8044911 DOI: 10.3389/fmicb.2021.621875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 02/24/2021] [Indexed: 11/13/2022] Open
Abstract
Amino-phosphonate derivative R-diphenyl-1-(4-methylbenzothiazole-2-amino)-1-(thiphene-2-yl)-methylphosphonate (Q-R) has a high protective anti-tobacco mosaic virus (TMV) activity. However, the mechanism responsible for Q-R's effect on TMV infection is largely unknown. Here, we studied the expression levels of harpin-binding protein 1 (HrBP1) and pathogenesis-related protein-1a (PR-1a) in TMV-infected tobacco plants by using reverse transcription quantitative real-time PCR. Then, we verified the interactions between Q-R and the HrBP1 protein from Escherichia coli using isothermal titration calorimetry and studied the Q-R-associated assembly of HrBP1 using size-exclusion chromatography. The results showed that the expression levels of HrBP1 and PR-1a genes were significantly increased by Q-R at the transcriptional level in TMV-infected tobacco plants, and the E. coli-expressed HrBP1 protein was assembled into oligomers by Q-R via binding to HrBP1 with a dissociation constant of 1.19 μM. We, therefore, concluded that Q-R activated the HrBP1 and PR-1a genes and enhanced the ability of HrBP1 to assemble in tobacco plants.
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Affiliation(s)
- Maoxi Huang
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Guiyang, China
| | - Yunlong Yan
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Guiyang, China.,College of Agriculture, Guizhou University, Guiyang, China
| | - Li Wang
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Guiyang, China.,College of Agriculture, Guizhou University, Guiyang, China
| | - Jun Chen
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Guiyang, China.,College of Agriculture, Guizhou University, Guiyang, China
| | - Tao Liu
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Guiyang, China
| | - Xin Xie
- College of Agriculture, Guizhou University, Guiyang, China
| | - Xiangyang Li
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Guiyang, China
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Li X, Yang X, Zheng X, Bai M, Hu D. Review on Structures of Pesticide Targets. Int J Mol Sci 2020; 21:E7144. [PMID: 32998191 PMCID: PMC7582455 DOI: 10.3390/ijms21197144] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 09/23/2020] [Accepted: 09/25/2020] [Indexed: 12/12/2022] Open
Abstract
Molecular targets play important roles in agrochemical discovery. Numerous pesticides target the key proteins in pathogens, insect, or plants. Investigating ligand-binding pockets and/or active sites in the proteins' structures is usually the first step in designing new green pesticides. Thus, molecular target structures are extremely important for the discovery and development of such pesticides. In this manuscript, we present a review of the molecular target structures, including those of antiviral, fungicidal, bactericidal, insecticidal, herbicidal, and plant growth-regulator targets, currently used in agrochemical research. The data will be helpful in pesticide design and the discovery of new green pesticides.
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Affiliation(s)
- Xiangyang Li
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Guiyang 550025, China;
| | - Xueqing Yang
- College of Plant Protection, Shenyang Agricultural University, Shenyang 110866, China;
| | - Xiaodong Zheng
- College of Horticulture, Qingdao Agricultural University, Qingdao 266109, China;
| | - Miao Bai
- College of Horticulture, Hunan Agricultural University, Changsha 410128, China;
| | - Deyu Hu
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Guiyang 550025, China;
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Yang H, Zu G, Liu Y, Xie D, Gan X, Song B. Tomato Chlorosis Virus Minor Coat Protein as a Novel Target To Screen Antiviral Drugs. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2020; 68:3425-3433. [PMID: 32091891 DOI: 10.1021/acs.jafc.9b08215] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Minor coat protein (mCP), an important component of tomato chlorosis virus (ToCV), plays a significant role in the process of virus assembly and movement and is directly related to the virus-insect transmission. Therefore, ToCV mCP could be considered as a potent target for anti-ToCV drugs. In this study, ToCV mCP was first cloned, expressed, purified, and a novel target to screen the antiviral agents. The results showed that some antiviral compounds bound to ToCV mCP with strongly affinities in vitro, including quinazoline derivatives 4a and 4b, Ningnanmycin, and Ribavirin. Subsequently, three-dimensional-quantitative structure-activity relationship (3D-QSAR) analysis was performed based on the binding affinities, and the model indicated that 4a and 4b had indeed stronger binding effects on ToCV mCP than other quinazoline derivatives. Finally, the anti-ToCV activities of compounds 4a and 4b were evaluated by quantitative real-time polymerase chain reaction in vivo. Compounds 4a and 4b inhibited infection of ToCV in the host and as well as reduced the level of ToCV mCP gene expression. Thus, ToCV mCP can be used as a novel drug target for screening anti-ToCV agents, and the ligand-based 3D-QSAR analysis of quinazoline derivatives provided new insights into the design and optimization of novel anti-ToCV drug molecules based on ToCV mCP.
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Affiliation(s)
- Huanyu Yang
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, China
| | - Guangcheng Zu
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, China
| | - Yuewen Liu
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, China
| | - Dandan Xie
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, China
| | - Xiuhai Gan
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, China
| | - Baoan Song
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, China
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Wang D, Xie X, Gao D, Chen K, Chen Z, Jin L, Li X, Song B. Dufulin Intervenes the Viroplasmic Proteins as the Mechanism of Action against Southern Rice Black-Streaked Dwarf Virus. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2019; 67:11380-11387. [PMID: 31535865 DOI: 10.1021/acs.jafc.9b05793] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Southern rice black-streaked dwarf virus (SRBSDV) causes disease in crops, which reduces the quality and yield. Several commercial antiviral agents are available to control the SRBSDV induced disease. However, the mechanism of antiviral agents controlling SRBSDV is largely unknown. Identifying targets in SRBSDV is a key step of antiviral agent discovery. Here, we investigated the potential protein target of the antiviral agent dufulin. We cloned and expressed a soluble viroplasmic P6 protein in the prokaryote Escherichia coli and the eukaryote Spodoptera frugiperda 9. The dissociation constants of dufulin with the purified P6 protein from E. coli and S. frugiperda 9 expression systems were 4.49 and 4.95 μM, respectively, indicating a strong binding affinity between dufulin and P6 protein. In vivo, dufulin significantly inhibited the expression of both P6 protein and P6 gene in the SRBSDV-infected rice leaves. This inhibition on P6 protein expression was also observed in transformed Nicotiana benthamiana where the P6 was overexpressed. Our data also showed that dufulin inhibited the duplication of SRBSDV in a dose-dependent manner in infected rice leaves with a half maximum effective concentration of 3.32 mM. It is therefore concluded that dufulin targets the viroplasmic protein P6 to inhibit the virulence of SRBSDV.
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Ran L, Ding Y, Luo L, Gan X, Li X, Chen Y, Hu D, Song B. Interaction research on an antiviral molecule that targets the coat protein of southern rice black-streaked dwarf virus. Int J Biol Macromol 2017; 103:919-930. [DOI: 10.1016/j.ijbiomac.2017.05.059] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 05/14/2017] [Indexed: 01/10/2023]
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