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Fabiani M, Castro EF, Battini L, Rosas RA, Gärtner B, Bollini M, Cavallaro LV. Two thiosemicarbazones derived from 1-indanone as potent non-nucleoside inhibitors of bovine viral diarrhea virus of different genotypes and biotypes. Virology 2024; 598:110189. [PMID: 39089051 DOI: 10.1016/j.virol.2024.110189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2024] [Revised: 07/10/2024] [Accepted: 07/21/2024] [Indexed: 08/03/2024]
Abstract
Bovine viral diarrhea virus (BVDV) is a widespread pathogen of cattle and other mammals that causes major economic losses in the livestock industry. N4-TSC and 6NO2-TSC are two thiosemicarbazones derived from 1-indanone that exhibit anti-BVDV activity in vitro. These compounds selectively inhibit BVDV and are effective against both cytopathic and non-cytopathic BVDV-1 and BVDV-2 strains. We confirmed that N4-TSC acts at the onset of viral RNA synthesis, as previously reported for 6NO2-TSC. Moreover, resistance selection and characterization showed that N4-TSCR mutants were highly resistant to N4-TSC but remained susceptible to 6NO2-TSC. In contrast, 6NO2-TSCR mutants were resistant to both compounds. Additionally, mutations N264D and A392E were found in the viral RNA-dependent RNA polymerase (RdRp) of N4-TSCR mutants, whereas I261 M was found in 6NO2-TSCR mutants. These mutations lay in a hydrophobic pocket within the fingertips region of BVDV RdRp that has been described as a "hot spot" for BVDV non-nucleoside inhibitors.
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Affiliation(s)
- Matías Fabiani
- Cátedra de Virología, Departamento de Microbiología, Inmunología, Biotecnología y Genética, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina; Instituto de Investigaciones en Bacteriología y Virología Molecular (IBaViM), Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina.
| | - Eliana F Castro
- Cátedra de Virología, Departamento de Microbiología, Inmunología, Biotecnología y Genética, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina
| | - Leandro Battini
- Laboratorio de Química Medicinal, Centro de Investigaciones en Bionanociencias (CIBION), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ciudad Autónoma de Buenos Aires, Argentina
| | - Rocío A Rosas
- Cátedra de Virología, Departamento de Microbiología, Inmunología, Biotecnología y Genética, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina; Instituto de Investigaciones en Bacteriología y Virología Molecular (IBaViM), Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina
| | - Benjamin Gärtner
- Cátedra de Virología, Departamento de Microbiología, Inmunología, Biotecnología y Genética, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina
| | - Mariela Bollini
- Laboratorio de Química Medicinal, Centro de Investigaciones en Bionanociencias (CIBION), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ciudad Autónoma de Buenos Aires, Argentina
| | - Lucía V Cavallaro
- Cátedra de Virología, Departamento de Microbiología, Inmunología, Biotecnología y Genética, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina; Instituto de Investigaciones en Bacteriología y Virología Molecular (IBaViM), Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina.
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2
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Wang X, Jing X, Shi J, Liu Q, Shen S, Cheung PPH, Wu J, Deng F, Gong P. A jingmenvirus RNA-dependent RNA polymerase structurally resembles the flavivirus counterpart but with different features at the initiation phase. Nucleic Acids Res 2024; 52:3278-3290. [PMID: 38296832 PMCID: PMC11014250 DOI: 10.1093/nar/gkae042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 01/06/2024] [Accepted: 01/11/2024] [Indexed: 02/02/2024] Open
Abstract
Jingmenviruses are a category of emerging segmented viruses that have garnered global attention in recent years, and are close relatives of the flaviviruses in the Flaviviridae family. One of their genome segments encodes NSP1 homologous to flavivirus NS5. NSP1 comprises both the methyltransferase (MTase) and RNA-dependent RNA polymerase (RdRP) modules playing essential roles in viral genome replication and capping. Here we solved a 1.8-Å resolution crystal structure of the NSP1 RdRP module from Jingmen tick virus (JMTV), the type species of jingmenviruses. The structure highly resembles flavivirus NS5 RdRP despite a sequence identity less than 30%. NSP1 RdRP enzymatic properties were dissected in a comparative setting with several representative Flaviviridae RdRPs included. Our data indicate that JMTV NSP1 produces characteristic 3-mer abortive products similar to the hepatitis C virus RdRP, and exhibits the highest preference of terminal initiation and shorter-primer usage. Unlike flavivirus NS5, JMTV RdRP may require the MTase for optimal transition from initiation to elongation, as an MTase-less NSP1 construct produced more 4-5-mer intermediate products than the full-length protein. Taken together, this work consolidates the evolutionary relationship between the jingmenvirus group and the Flaviviridae family, providing a basis to the further understanding of their viral replication/transcription process.
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Affiliation(s)
- Xinyu Wang
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, No. 262 Jin Long Street, Wuhan, Hubei 430207, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xuping Jing
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, No. 262 Jin Long Street, Wuhan, Hubei 430207, China
| | - Junming Shi
- University of Chinese Academy of Sciences, Beijing 100049, China
- State Key Laboratory of Virology, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, No.262 Jin Long Street, Wuhan, Hubei 430207, China
| | - Qiaojie Liu
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, No. 262 Jin Long Street, Wuhan, Hubei 430207, China
| | - Shu Shen
- State Key Laboratory of Virology, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, No.262 Jin Long Street, Wuhan, Hubei 430207, China
| | - Peter Pak-Hang Cheung
- Department of Chemical Pathology, Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong, China
| | - Jiqin Wu
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, No. 262 Jin Long Street, Wuhan, Hubei 430207, China
| | - Fei Deng
- State Key Laboratory of Virology, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, No.262 Jin Long Street, Wuhan, Hubei 430207, China
| | - Peng Gong
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, No. 262 Jin Long Street, Wuhan, Hubei 430207, China
- Drug Discovery Center for Infectious Diseases, Nankai University, Tianjin 300350, China
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3
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Yin J, Diao N, Tian T, Wang Q, Ma S, He N, Zhou H, Zhou Z, Jia W, Wang X, Shi K, Du R. ARHGEF18 can promote BVDV NS5B activation of the host NF-κB signaling pathway by combining with the NS5B-palm domain. Vet Microbiol 2024; 291:109911. [PMID: 38367539 DOI: 10.1016/j.vetmic.2023.109911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 10/31/2023] [Accepted: 11/04/2023] [Indexed: 02/19/2024]
Abstract
Rho guanine nucleotide exchange factor 18 (ARHGEF18) is a member of the Rho guanine nucleotide exchange factor (RhoGEF) family. RhoGEF plays an important role in the occurrence of tumors and neurological diseases; however, its involvement in host cell resistance against pathogenic microorganisms is mostly unknown. Herein, we report that bovine viral diarrhea virus (BVDV) nonstructural protein 5B (NS5B) can activate the nuclear factor kappa B (NF-κB) signaling pathway to induce an immune response. To clarify the functional domains of NS5B that activate NF-κB signaling, the six structural domains of NS5B were expressed separately: NS5B-core, NS5B-finger, NS5B-palm, NS5B-thumb, NS5B-N and NS5B-c domain. We preliminarily determined that the functional domains of NS5B that activate NF-κB signaling are the finger and palm domains. We used a bovine kidney cell cDNA library and yeast two-hybrid technology to identify that the host protein ARHGEF18 interacts with NS5B. Co-immunoprecipitation assays showed that ARHGEF18 interacts strongly with NS5B-palm. Interestingly ARHGEF18 could promote NF-κB signaling activation by BVDV NS5B. In addition silencing ARHGEF18 significantly inhibited NS5B-palm activation of NF-κB signaling. We concluded that ARHGEF18 can bind to BVDV NS5B through the palm domain to activate the NF-κB pathway. These findings provide direct evidence that BVDV NS5B induces immune responses by activating NF-κB signaling.
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Affiliation(s)
- Jiying Yin
- College of Animal Science and Technology, Jilin Agricultural University, Changchun 130118, China
| | - Naichao Diao
- College of Chinese Medicinal Materials, Jilin Agricultural University, Changchun 130118, China
| | - Tian Tian
- College of Animal Science and Technology, Jilin Agricultural University, Changchun 130118, China
| | - Qi Wang
- College of Animal Science and Technology, Jilin Agricultural University, Changchun 130118, China
| | - Shuqi Ma
- College of Animal Science and Technology, Jilin Agricultural University, Changchun 130118, China
| | - Ning He
- College of Animal Science and Technology, Jilin Agricultural University, Changchun 130118, China
| | - Hongming Zhou
- College of Animal Science and Technology, Jilin Agricultural University, Changchun 130118, China
| | - Zehui Zhou
- College of Animal Science and Technology, Jilin Agricultural University, Changchun 130118, China
| | - Wenyi Jia
- College of Animal Science and Technology, Jilin Agricultural University, Changchun 130118, China
| | - Xiaonan Wang
- College of Animal Science and Technology, Jilin Agricultural University, Changchun 130118, China
| | - Kun Shi
- College of Chinese Medicinal Materials, Jilin Agricultural University, Changchun 130118, China.
| | - Rui Du
- College of Chinese Medicinal Materials, Jilin Agricultural University, Changchun 130118, China; Laboratory of Production and Product Application of Sika Deer of Jilin Province, Jilin Agricultural University, Changchun 130118, China; Key Laboratory of Animal Production, Product Quality and Security, Ministry of Education, Jilin Agricultural University, Changchun 130118, China.
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Template Entrance Channel as Possible Allosteric Inhibition and Resistance Site for Quinolines Tricyclic Derivatives in RNA Dependent RNA Polymerase of Bovine Viral Diarrhea Virus. Pharmaceuticals (Basel) 2023; 16:ph16030376. [PMID: 36986476 PMCID: PMC10058290 DOI: 10.3390/ph16030376] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 02/16/2023] [Accepted: 02/25/2023] [Indexed: 03/06/2023] Open
Abstract
The development of potent non-nucleoside inhibitors (NNIs) could be an alternate strategy to combating infectious bovine viral diarrhea virus (BVDV), other than the traditional vaccination. RNA-dependent RNA polymerase (RdRp) is an essential enzyme for viral replication; therefore, it is one of the primary targets for countermeasures against infectious diseases. The reported NNIs, belonging to the classes of quinolines (2h: imidazo[4,5-g]quinolines and 5m: pyrido[2,3-g] quinoxalines), displayed activity in cell-based and enzyme-based assays. Nevertheless, the RdRp binding site and microscopic mechanistic action are still elusive, and can be explored at a molecular level. Here, we employed a varied computational arsenal, including conventional and accelerated methods, to identify quinoline compounds’ most likely binding sites. Our study revealed A392 and I261 as the mutations that can render RdRp resistant against quinoline compounds. In particular, for ligand 2h, mutation of A392E is the most probable mutation. The loop L1 and linker of the fingertip is recognized as a pivotal structural determinant for the stability and escape of quinoline compounds. Overall, this work demonstrates that the quinoline inhibitors bind at the template entrance channel, which is governed by conformational dynamics of interactions with loops and linker residues, and reveals structural and mechanistic insights into inhibition phenomena, for the discovery of improved antivirals.
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Kumar G, Singh AK, Agarwal D. Structural and functional characterization of RNA dependent RNA polymerase of Macrobrachium rosenbergii nodavirus (MnRdRp). J Biomol Struct Dyn 2023; 41:12825-12837. [PMID: 36757137 DOI: 10.1080/07391102.2023.2175384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 01/07/2023] [Indexed: 02/10/2023]
Abstract
Macrobrachium rosenbergii is a highly valued farmed freshwater species and its production has been affected globally by white tail disease caused by M. rosenbergii nodavirus (MrNV). MrNV is a single stranded positive sense RNA virus encoding RNA-dependent RNA polymerase (RdRp) for genome replication. Due to its essentiality for pathogenesis, it is an important drug target. The domain prediction of the complete sequence revealed the presence of two enzymatic regions namely methyl transferase and RdRp separated by transmembrane region. The predicted three-dimensional (3D) structure of MnRdRp using AlphaFold 2 shows that the structure is composed of three major sub-domains common for other polymerases namely fingers, palm and thumb. Structural similarity search revealed its similarity with other flaviviridea members especially with BVDV RdRp (BvdvRdRp). The structure of fingers and palm sub-domains is more conserved than the thumb sub-domain. A small α-helix named 'priming helix' having conserve Tyr was identified at position 829-833 with a potential role in de novo initiation. Analysis of electrostatic potential revealed that nucleotide and template channels are electropositive. Metal binding residues were identified as Asp599, Asp704 and Asp705. The α and β phosphates of incoming nucleotide interact with two Mn2+, Arg455 and Arg537. For recognition of 2'-OH of incoming rNTP, Asp604, Ser661 and Asn670 were identified which can form H-bond network with 2'-OH group. Docking study revealed that Dasabuvir can potentially inhibit MnRdRp. The study concluded that the overall structure and function of MnRdRp are similar to Flaviviridae polymerases and their inhibitors can work against this enzyme.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Gulshan Kumar
- College of Fisheries Science Gunla, Birsa Agricultural University, Ranchi, Jharkhand, India
| | - A K Singh
- College of Fisheries Science Gunla, Birsa Agricultural University, Ranchi, Jharkhand, India
| | - Deepak Agarwal
- TNJFU, Institute of Fisheries Post Graduate Studies, OMR, Chennai, Tamil Nadu, India
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6
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Structural basis of transition from initiation to elongation in de novo viral RNA-dependent RNA polymerases. Proc Natl Acad Sci U S A 2023; 120:e2211425120. [PMID: 36577062 PMCID: PMC9910504 DOI: 10.1073/pnas.2211425120] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
De novo viral RNA-dependent RNA polymerases (RdRPs) utilize their priming element (PE) to facilitate accurate initiation. Upon transition to elongation, the PE has to retreat from the active site to give room to the template-product RNA duplex. However, PE conformational change upon this transition and the role of PE at elongation both remain elusive. Here, we report crystal structures of RdRP elongation complex (EC) from dengue virus serotype 2 (DENV2), demonstrating a dramatic refolding of PE that allows establishment of interactions with the RNA duplex backbone approved to be essential for EC stability. Enzymology data from both DENV2 and hepatitis C virus (HCV) RdRPs suggest that critical transition of the refolding likely occurs after synthesis of a 4- to 5-nucleotide (nt) product together providing a key basis in understanding viral RdRP transition from initiation to elongation.
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7
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Ullah A, Atia-Tul-Wahab, Gong P, Khan AM, Choudhary MI. Identification of new inhibitors of NS5 from dengue virus using saturation transfer difference (STD-NMR) and molecular docking studies. RSC Adv 2022; 13:355-369. [PMID: 36605638 PMCID: PMC9768849 DOI: 10.1039/d2ra04836a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Accepted: 11/15/2022] [Indexed: 12/24/2022] Open
Abstract
The rapid spread of dengue virus has now emerged as a major health problem worldwide, particularly in tropical and sub-tropical regions. Nearly half of the human population is at risk of getting infection. Among the proteomes of dengue virus, nonstructural protein NS5 is conserved across the genus Flavivirus. NS5 comprises methyltransferase enzyme (MTase) domain, which helps in viral RNA capping, and RNA-dependent RNA polymerase (RdRp) domain, which is important for the virus replication. Negative modulation of NS5 decreases its activity and associated functions. Despite recent advances, there is still an immense need for effective approaches toward drug discovery against dengue virus. Drug repurposing is an approach to identify the new therapeutic indications of already approved drugs, for the treatment of both common and rare diseases, and can potentially lower the cost, and time required for drug discovery and development. In this study, we evaluated 75 compounds (grouped into 15 mixtures), including 13 natural compounds and 62 drugs, by using biophysical methods, for their ability to interact with NS5 protein, which were further validated by molecular docking and simulation studies. Our current study led to the identification of 12 ligands, including both 9 US-FDA approved drugs and 3 natural products that need to be further studied as potential antiviral agents against dengue virus.
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Affiliation(s)
- Asmat Ullah
- Dr Panjwani Center for Molecular Medicine and Drug Research, International Center of Chemical and Biological Sciences, University of Karachi Karachi 75270 Pakistan
| | - Atia-Tul-Wahab
- Dr Panjwani Center for Molecular Medicine and Drug Research, International Center of Chemical and Biological Sciences, University of Karachi Karachi 75270 Pakistan
| | - Peng Gong
- Wuhan Institute of Virology, Chinese Academy of Sciences Wuhan Hubei 430071 China
| | - Abdul Mateen Khan
- H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi Karachi 75270 Pakistan
| | - M Iqbal Choudhary
- Dr Panjwani Center for Molecular Medicine and Drug Research, International Center of Chemical and Biological Sciences, University of Karachi Karachi 75270 Pakistan
- H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi Karachi 75270 Pakistan
- Department of Biochemistry, Faculty of Science, King Abdulaziz University Jeddah-21589 Saudi Arabia
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8
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Kumar S, Verma A, Yadav P, Dubey SK, Azhar EI, Maitra SS, Dwivedi VD. Molecular pathogenesis of Japanese encephalitis and possible therapeutic strategies. Arch Virol 2022; 167:1739-1762. [PMID: 35654913 PMCID: PMC9162114 DOI: 10.1007/s00705-022-05481-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2021] [Accepted: 03/10/2022] [Indexed: 12/26/2022]
Abstract
Japanese encephalitis virus (JEV), a single-stranded, enveloped RNA virus, is a health concern across Asian countries, associated with severe neurological disorders, especially in children. Primarily, pigs, bats, and birds are the natural hosts for JEV, but humans are infected incidentally. JEV requires a few host proteins for its entry and replication inside the mammalian host cell. The endoplasmic reticulum (ER) plays a significant role in JEV genome replication and assembly. During this process, the ER undergoes stress due to its remodelling and accumulation of viral particles and unfolded proteins, leading to an unfolded protein response (UPR). Here, we review the overall strategy used by JEV to infect the host cell and various cytopathic effects caused by JEV infection. We also highlight the role of JEV structural proteins (SPs) and non-structural proteins (NSPs) at various stages of the JEV life cycle that are involved in up- and downregulation of different host proteins and are potentially relevant for developing efficient therapeutic drugs.
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Affiliation(s)
- Sanjay Kumar
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, 110067 India
- Center for Bioinformatics, Computational and Systems Biology, Pathfinder Research and Training Foundation, Greater Noida, India
| | - Akanksha Verma
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, 110067 India
| | - Pardeep Yadav
- Department of Biotechnology, School of Engineering and Technology, Sharda University, Greater Noida, Uttar Pradesh 201310 India
- Center for Bioinformatics, Computational and Systems Biology, Pathfinder Research and Training Foundation, Greater Noida, India
| | | | - Esam Ibraheem Azhar
- Special Infectious Agents Unit-BSL3, King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia
- Department of Medical Laboratory Technology, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah, 21589 Saudi Arabia
| | - S. S. Maitra
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, 110067 India
| | - Vivek Dhar Dwivedi
- Center for Bioinformatics, Computational and Systems Biology, Pathfinder Research and Training Foundation, Greater Noida, India
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9
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He D, Li X, Wang S, Wang C, Liu X, Zhang Y, Cui Y, Yu S. Mechanism of drug resistance of BVDV induced by F224S mutation in RdRp: A case study of VP32947. Comput Biol Chem 2022; 99:107715. [PMID: 35751995 DOI: 10.1016/j.compbiolchem.2022.107715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 06/04/2022] [Accepted: 06/16/2022] [Indexed: 11/19/2022]
Abstract
Bovine viral diarrhea virus (BVDV) is an enveloped virus with an RNA genome, causing serious economic losses to the areas dominated by livestock industry. Currently, although several compounds with biological activities of inhibiting virus replication have been reported, amino acid mutations (especially F224S mutation) frequently occurring in the RNA-dependent RNA polymerase (RdRp) have greatly reduce their value of further research. In this study, we introduced an effective and rapid in silico strategy to explore the differences in the binding modes of VP32947 between the wild/mutant-type RdRp at the molecular level, and further explained the main reasons for the variations in the inhibitory activities of VP32947 against the two types of enzymes. Firstly, the binding site of VP32947 in the finger domain was determined based on the previously reported experimental data, and the initial conformation of VP32947 in the wild RdRp was constructed using molecular docking. Then, the mutant research system was obtained directly by artificial mutation strategy. Afterwards, the built research systems were subjected to microsecond-timescale molecular dynamic simulation, and the conformational and energic profile analyses were performed according to the simulation trajectories. It was found that after 1 μs simulation, VP32947 in the mutant system was transferred to the left side of Loop α, and its interactions with the residues in the loop region were weakened. However, VP32947 in the wild system remained at the right side of Loop α, and could have a good fit with the sub-pocket formed by F224, I261, P262, N264, S532, which was conducive to maintaining its stable binding conformation in the wild RdRp. The illustration of the difference in the binding mechanisms of VP32947 in the wild/mutant RdRp would provide a theoretical basis for the rational design of innovative inhibitors based on the enzyme.
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Affiliation(s)
- Dian He
- Gansu Province Livestock Embryo Engineering Research Center, College of Veterinary Medicine, Gansu Agricultural University, Lanzhou 730070, PR China.
| | - Xuedong Li
- College of Pharmacy, Hebei Medical University, Shijiazhuang 050017, PR China
| | - Songsong Wang
- College of Pharmacy, Hebei Medical University, Shijiazhuang 050017, PR China
| | - Chengzhao Wang
- College of Pharmacy, Hebei Medical University, Shijiazhuang 050017, PR China
| | - Xingang Liu
- College of Pharmacy, Hebei Medical University, Shijiazhuang 050017, PR China
| | - Yang Zhang
- College of Pharmacy, Hebei Medical University, Shijiazhuang 050017, PR China.
| | - Yan Cui
- Gansu Province Livestock Embryo Engineering Research Center, College of Veterinary Medicine, Gansu Agricultural University, Lanzhou 730070, PR China
| | - Sijiu Yu
- Gansu Province Livestock Embryo Engineering Research Center, College of Veterinary Medicine, Gansu Agricultural University, Lanzhou 730070, PR China.
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10
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Tan YB, Lello LS, Liu X, Law YS, Kang C, Lescar J, Zheng J, Merits A, Luo D. Crystal structures of alphavirus nonstructural protein 4 (nsP4) reveal an intrinsically dynamic RNA-dependent RNA polymerase fold. Nucleic Acids Res 2022; 50:1000-1016. [PMID: 35037043 PMCID: PMC8789068 DOI: 10.1093/nar/gkab1302] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 12/14/2021] [Accepted: 12/23/2021] [Indexed: 11/12/2022] Open
Abstract
Alphaviruses such as Ross River virus (RRV), chikungunya virus (CHIKV), Sindbis virus (SINV), and Venezuelan equine encephalitis virus (VEEV) are mosquito-borne pathogens that can cause arthritis or encephalitis diseases. Nonstructural protein 4 (nsP4) of alphaviruses possesses RNA-dependent RNA polymerase (RdRp) activity essential for viral RNA replication. No 3D structure has been available for nsP4 of any alphaviruses despite its importance for understanding alphaviral RNA replication and for the design of antiviral drugs. Here, we report crystal structures of the RdRp domain of nsP4 from both RRV and SINV determined at resolutions of 2.6 Å and 1.9 Å. The structure of the alphavirus RdRp domain appears most closely related to RdRps from pestiviruses, noroviruses, and picornaviruses. Hydrogen-deuterium exchange mass spectrometry (HDX-MS) and nuclear magnetic resonance (NMR) methods showed that in solution, nsP4 is highly dynamic with an intrinsically disordered N-terminal domain. Both full-length nsP4 and the RdRp domain were capable to catalyze RNA polymerization. Structure-guided mutagenesis using a trans-replicase system identified nsP4 regions critical for viral RNA replication.
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Affiliation(s)
- Yaw Bia Tan
- Lee Kong Chian School of Medicine, Nanyang Technological University, 59 Nanyang Drive, Singapore 636921.,NTU Institute of Structural Biology, Nanyang Technological University, 59 Nanyang Drive, Singapore 636921
| | - Laura Sandra Lello
- University of Tartu, Institute of Technology, Nooruse 1, 50411 Tartu, Estonia
| | - Xin Liu
- Shanghai Institute of Materia Medica, China Academy of Sciences, 555 Zu Chong Zhi Road, Zhang Jiang Hi-Tech Park, Pudong, Shanghai, China
| | - Yee-Song Law
- Lee Kong Chian School of Medicine, Nanyang Technological University, 59 Nanyang Drive, Singapore 636921.,NTU Institute of Structural Biology, Nanyang Technological University, 59 Nanyang Drive, Singapore 636921
| | - Congbao Kang
- Experimental Drug Development Centre, Agency for Science, Technology and Research (A*STAR), 10 Biopolis Rd, #05-01/06 Chromos, Singapore138670
| | - Julien Lescar
- NTU Institute of Structural Biology, Nanyang Technological University, 59 Nanyang Drive, Singapore 636921.,School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore
| | - Jie Zheng
- Shanghai Institute of Materia Medica, China Academy of Sciences, 555 Zu Chong Zhi Road, Zhang Jiang Hi-Tech Park, Pudong, Shanghai, China
| | - Andres Merits
- University of Tartu, Institute of Technology, Nooruse 1, 50411 Tartu, Estonia
| | - Dahai Luo
- Lee Kong Chian School of Medicine, Nanyang Technological University, 59 Nanyang Drive, Singapore 636921.,NTU Institute of Structural Biology, Nanyang Technological University, 59 Nanyang Drive, Singapore 636921.,School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore
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11
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IMTIAZ F, PASHA MK. A systematic review of RdRp of SARS-CoV-2 through artificial intelligence and machine learning utilizing structure-based drug design strategy. Turk J Chem 2021; 46:583-594. [PMID: 37720604 PMCID: PMC10503974 DOI: 10.55730/1300-0527.3355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 06/16/2022] [Accepted: 12/27/2021] [Indexed: 11/13/2022] Open
Abstract
Since the coronavirus disease has been declared a global pandemic, it had posed a challenge among researchers and raised common awareness and collaborative efforts towards finding the solution. Caused by severe acute respiratory coronavirus syndrome-2 (SARS-CoV-2), coronavirus drug design strategy needs to be optimized. It is understandable that cognizance of the pathobiology of COVID-19 can help scientists in the development and discovery of therapeutically effective antiviral drugs by elucidating the unknown viral pathways and structures. Considering the role of artificial intelligence and machine learning with its advancements in the field of science, it is rational to use these methods which can aid in the discovery of new potent candidates in silico. Our review utilizes similar methodologies and focuses on RNA-dependent RNA polymerase (RdRp), based on its importance as an essential element for virus replication and also a promising target for COVID-19 therapeutics. Artificial neural network technique was used to shortlist articles with the support of PRISMA, from different research platforms including Scopus, PubMed, PubChem, and Web of Science, through a combination of keywords. "English language", from the year "2000" and "published articles in journals" were selected to carry out this research. We summarized that structural details of the RdRp reviewed in this analysis will have the potential to be taken into consideration when developing therapeutic solutions and if further multidisciplinary efforts are taken in this domain then potential clinical candidates for RdRp of SARS-CoV-2 could be successfully delivered for experimental validations.
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Affiliation(s)
- Fariha IMTIAZ
- Punjab University College of Pharmacy, University of the Punjab, Lahore,
Pakistan
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12
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Newcomer BW. 75 years of bovine viral diarrhea virus: Current status and future applications of the use of directed antivirals. Antiviral Res 2021; 196:105205. [PMID: 34742739 DOI: 10.1016/j.antiviral.2021.105205] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2021] [Revised: 10/30/2021] [Accepted: 11/02/2021] [Indexed: 01/03/2023]
Abstract
Bovine viral diarrhea virus (BVDV) was first reported 75 years ago and remains a source of major financial and production losses in the North American cattle industry. Currently, control methods in North America primarily center around biosecurity and vaccination programs; however, despite high levels of vaccination, the virus persists in the cattle herd due at least in part to the often-insidious nature of disease and the constant viremia and viral shedding of persistently infected animals which act as a reservoir for the virus. Continued development of targeted antivirals represents an additional tool for the prevention of BVDV-associated losses. Currently, in vivo studies of BVDV antivirals are relatively limited and have primarily been directed at the RNA-dependent RNA polymerase which represents the viral target with the highest potential for commercial development. Additional live animal studies have explored the potential of exogenous interferon treatment. Future research of commercial antivirals must focus on the establishment and validation of in vivo efficacy for compounds with demonstrated antiviral potential. The areas which provide the most viable economic justification for the research and development of antivirals drugs are the fed cattle sector, outbreak control, and wildlife or animals of high genetic value. With further development, targeted antivirals represent an additional tool for the management and control of BVDV in North American cattle herds.
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Affiliation(s)
- Benjamin W Newcomer
- Veterinary Education, Research, & Outreach Program, Texas A&M and West Texas A&M Universities, Canyon, TX, 79016, USA.
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13
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Characteristics of Classical Swine Fever Virus Variants Derived from Live Attenuated GPE - Vaccine Seed. Viruses 2021; 13:v13081672. [PMID: 34452536 PMCID: PMC8402697 DOI: 10.3390/v13081672] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 08/18/2021] [Accepted: 08/19/2021] [Indexed: 11/17/2022] Open
Abstract
The GPE- strain is a live attenuated vaccine for classical swine fever (CSF) developed in Japan. In the context of increasing attention for the differentiating infected from vaccinated animals (DIVA) concept, the achievement of CSF eradication with the GPE- proposes it as a preferable backbone for a recombinant CSF marker vaccine. While its infectious cDNA clone, vGPE-, is well characterized, 10 amino acid substitutions were recognized in the genome, compared to the original GPE- vaccine seed. To clarify the GPE- seed availability, this study aimed to generate and characterize a clone possessing the identical amino acid sequence to the GPE- seed. The attempt resulted in the loss of the infectious GPE- seed clone production due to the impaired replication by an amino acid substitution in the viral polymerase NS5B. Accordingly, replication-competent GPE- seed variant clones were produced. Although they were mostly restricted to propagate in the tonsils of pigs, similarly to vGPE-, their type I interferon-inducing capacity was significantly lower than that of vGPE-. Taken together, vGPE- mainly retains ideal properties for the CSF vaccine, compared with the seed variants, and is probably useful in the development of a CSF marker vaccine.
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14
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Proline to Threonine Mutation at Position 162 of NS5B of Classical Swine Fever Virus Vaccine C Strain Promoted Genome Replication and Infectious Virus Production by Facilitating Initiation of RNA Synthesis. Viruses 2021; 13:v13081523. [PMID: 34452387 PMCID: PMC8402891 DOI: 10.3390/v13081523] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 07/29/2021] [Accepted: 07/30/2021] [Indexed: 12/11/2022] Open
Abstract
The 3′untranslated region (3′UTR) and NS5B of classical swine fever virus (CSFV) play vital roles in viral genome replication. In this study, two chimeric viruses, vC/SM3′UTR and vC/b3′UTR, with 3′UTR substitution of CSFV Shimen strain or bovine viral diarrhea virus (BVDV) NADL strain, were constructed based on the infectious cDNA clone of CSFV vaccine C strain, respectively. After virus rescue, each recombinant chimeric virus was subjected to continuous passages in PK-15 cells. The representative passaged viruses were characterized and sequenced. Serial passages resulted in generation of mutations and the passaged viruses exhibited significantly increased genomic replication efficiency and infectious virus production compared to parent viruses. A proline to threonine mutation at position 162 of NS5B was identified in both passaged vC/SM3′UTR and vC/b3′UTR. We generated P162T mutants of two chimeras using the reverse genetics system, separately. The single P162T mutation in NS5B of vC/SM3′UTR or vC/b3′UTR played a key role in increased viral genome replication and infectious virus production. The P162T mutation increased vC/SM3′UTRP162T replication in rabbits. From RNA-dependent RNA polymerase (RdRp) assays in vitro, the NS5B containing P162T mutation (NS5BP162T) exhibited enhanced RdRp activity for different RNA templates. We further identified that the enhanced RdRp activity originated from increased initiation efficiency of RNA synthesis. These findings revealed a novel function for the NS5B residue 162 in modulating pestivirus replication.
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15
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Winston DS, Boehr DD. Allosteric and dynamic control of RNA-dependent RNA polymerase function and fidelity. Enzymes 2021; 49:149-193. [PMID: 34696831 DOI: 10.1016/bs.enz.2021.06.001] [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] [Indexed: 06/13/2023]
Abstract
All RNA viruses encode an RNA-dependent RNA polymerase (RdRp) responsible for genome replication. It is now recognized that enzymes in general, and RdRps specifically, are dynamic macromolecular machines such that their moving parts, including active site loops, play direct functional roles. While X-ray crystallography has provided deep insight into structural elements important for RdRp function, this methodology generally provides only static snapshots, and so is limited in its ability to report on dynamic fluctuations away from the lowest energy conformation. Nuclear magnetic resonance (NMR), molecular dynamics (MD) simulations and other biophysical techniques have brought new insight into RdRp function by their ability to characterize the trajectories, kinetics and thermodynamics of conformational motions. In particular, these methodologies have identified coordinated motions among conserved structural motifs necessary for nucleotide selection and incorporation. Disruption of these motions through amino acid substitutions or inhibitor binding impairs RdRp function. Understanding and re-engineering these motions thus provides exciting new avenues for anti-viral strategies. This chapter outlines the basics of these methodologies, summarizes the dynamic motions observed in different RdRps important for nucleotide selection and incorporation, and illustrates how this information can be leveraged towards rational vaccine strain development and anti-viral drug design.
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Affiliation(s)
- Dennis S Winston
- Department of Chemistry, The Pennsylvania State University, University Park, PA, United States
| | - David D Boehr
- Department of Chemistry, The Pennsylvania State University, University Park, PA, United States.
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16
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Structural basis for template switching by a group II intron-encoded non-LTR-retroelement reverse transcriptase. J Biol Chem 2021; 297:100971. [PMID: 34280434 PMCID: PMC8363836 DOI: 10.1016/j.jbc.2021.100971] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Revised: 06/30/2021] [Accepted: 07/15/2021] [Indexed: 12/02/2022] Open
Abstract
Reverse transcriptases (RTs) can switch template strands during complementary DNA synthesis, enabling them to join discontinuous nucleic acid sequences. Template switching (TS) plays crucial roles in retroviral replication and recombination, is used for adapter addition in RNA-Seq, and may contribute to retroelement fitness by increasing evolutionary diversity and enabling continuous complementary DNA synthesis on damaged templates. Here, we determined an X-ray crystal structure of a TS complex of a group II intron RT bound simultaneously to an acceptor RNA and donor RNA template–DNA primer heteroduplex with a 1-nt 3′-DNA overhang. The structure showed that the 3′ end of the acceptor RNA binds in a pocket formed by an N-terminal extension present in non–long terminal repeat–retroelement RTs and the RT fingertips loop, with the 3′ nucleotide of the acceptor base paired to the 1-nt 3′-DNA overhang and its penultimate nucleotide base paired to the incoming dNTP at the RT active site. Analysis of structure-guided mutations identified amino acids that contribute to acceptor RNA binding and a phenylalanine residue near the RT active site that mediates nontemplated nucleotide addition. Mutation of the latter residue decreased multiple sequential template switches in RNA-Seq. Our results provide new insights into the mechanisms of TS and nontemplated nucleotide addition by RTs, suggest how these reactions could be improved for RNA-Seq, and reveal common structural features for TS by non–long terminal repeat–retroelement RTs and viral RNA–dependent RNA polymerases.
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17
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Felicetti T, Pismataro MC, Cecchetti V, Tabarrini O, Massari S. Triazolopyrimidine Nuclei: Privileged Scaffolds for Developing Antiviral Agents with a Proper Pharmacokinetic Profile. Curr Med Chem 2021; 29:1379-1407. [PMID: 34042030 DOI: 10.2174/0929867328666210526120534] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 04/16/2021] [Accepted: 04/18/2021] [Indexed: 11/22/2022]
Abstract
Viruses are a continuing threat to global health. The lack or limited therapeutic armamentarium against some viral infections and increasing drug resistance issues make the search for new antiviral agents urgent. In recent years, a growing literature highlighted the use of triazolopyrimidine (TZP) heterocycles in the development of antiviral agents, with numerous compounds that showed potent antiviral activities against different RNA and DNA viruses. TZP core represents a privileged scaffold for achieving biologically active molecules, thanks to: i) the synthetic feasibility that allows to variously functionalize TZPs in the different positions of the nucleus, ii) the ability of TZP core to establish multiple interactions with the molecular target, and iii) its favorable pharmacokinetic properties. In the present review, after mentioning selected examples of TZP-based compounds with varied biological activities, we will focus on those antivirals that appeared in the literature in the last 10 years. Approaches used for their identification, the hit-to-lead studies, and the emerged structure-activity relationship will be described. A mention of the synthetic methodologies to prepare TZP nuclei will also be given. In addition, their mechanism of action, the binding mode within the biological target, and pharmacokinetic properties will be analyzed, highlighting the strengths and weaknesses of compounds based on the TZP scaffold, which is increasingly used in medicinal chemistry.
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Affiliation(s)
- Tommaso Felicetti
- Department of Pharmaceutical Sciences, University of Perugia, 06123 Perugia, Italy
| | | | - Violetta Cecchetti
- Department of Pharmaceutical Sciences, University of Perugia, 06123 Perugia, Italy
| | - Oriana Tabarrini
- Department of Pharmaceutical Sciences, University of Perugia, 06123 Perugia, Italy
| | - Serena Massari
- Department of Pharmaceutical Sciences, University of Perugia, 06123 Perugia, Italy
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18
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Riedel C, Aitkenhead H, El Omari K, Rümenapf T. Atypical Porcine Pestiviruses: Relationships and Conserved Structural Features. Viruses 2021; 13:v13050760. [PMID: 33926056 PMCID: PMC8146772 DOI: 10.3390/v13050760] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 04/23/2021] [Accepted: 04/23/2021] [Indexed: 01/22/2023] Open
Abstract
For two decades, the genus pestivirus has been expanding and the host range now extends to rodents, bats and marine mammals. In this review, we focus on one of the most diverse pestiviruses, atypical porcine pestivirus or pestivirus K, comparing its special traits to what is already known at the structural and functional level from other pestiviruses.
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Affiliation(s)
- Christiane Riedel
- Institute of Virology, Department of Pathobiology, University of Veterinary Medicine Vienna, 1210 Vienna, Austria;
- Correspondence:
| | - Hazel Aitkenhead
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, UK; (H.A.); (K.E.O.)
- Rutherford Appleton Laboratory, Research Complex at Harwell, Didcot OX11 0FA, UK
| | - Kamel El Omari
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, UK; (H.A.); (K.E.O.)
- Rutherford Appleton Laboratory, Research Complex at Harwell, Didcot OX11 0FA, UK
| | - Till Rümenapf
- Institute of Virology, Department of Pathobiology, University of Veterinary Medicine Vienna, 1210 Vienna, Austria;
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19
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Fernández GA, Castro EF, Rosas RA, Fidalgo DM, Adler NS, Battini L, España de Marco MJ, Fabiani M, Bruno AM, Bollini M, Cavallaro LV. Design and Optimization of Quinazoline Derivatives: New Non-nucleoside Inhibitors of Bovine Viral Diarrhea Virus. Front Chem 2020; 8:590235. [PMID: 33425849 PMCID: PMC7793975 DOI: 10.3389/fchem.2020.590235] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 11/09/2020] [Indexed: 01/30/2023] Open
Abstract
Bovine viral diarrhea virus (BVDV) belongs to the Pestivirus genus (Flaviviridae). In spite of the availability of vaccines, the virus is still causing substantial financial losses to the livestock industry. In this context, the use of antiviral agents could be an alternative strategy to control and reduce viral infections. The viral RNA-dependent RNA polymerase (RdRp) is essential for the replication of the viral genome and constitutes an attractive target for the identification of antiviral compounds. In a previous work, we have identified potential molecules that dock into an allosteric binding pocket of BVDV RdRp via a structure-based virtual screening approach. One of them, N-(2-morpholinoethyl)-2-phenylquinazolin-4-amine [1, 50% effective concentration (EC50) = 9.7 ± 0.5 μM], was selected to perform different chemical modifications. Among 24 derivatives synthesized, eight of them showed considerable antiviral activity. Molecular modeling of the most active compounds showed that they bind to a pocket located in the fingers and thumb domains in BVDV RdRp, which is different from that identified for other non-nucleoside inhibitors (NNIs) such as thiosemicarbazone (TSC). We selected compound 2-[4-(2-phenylquinazolin-4-yl)piperazin-1-yl]ethanol (1.9; EC50 = 1.7 ± 0.4 μM) for further analysis. Compound 1.9 was found to inhibit the in vitro replication of TSC-resistant BVDV variants, which carry the N264D mutation in the RdRp. In addition, 1.9 presented adequate solubility in different media and a high-stability profile in murine and bovine plasma.
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Affiliation(s)
- Gabriela A Fernández
- Laboratorio de Química Medicinal, Centro de Investigaciones en Bionanociencias (CIBION)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Eliana F Castro
- Centro de Investigaciones en Ciencias Veterinarias y Agronómicas, Instituto de Virología e Innovaciones Tecnológicas, Instituto Nacional de Tecnología Agropecuaria, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina.,Departamento de Microbiología, Inmunología, Biotecnología y Genética, Cátedra Virología, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Rocío A Rosas
- Departamento de Microbiología, Inmunología, Biotecnología y Genética, Cátedra Virología, Facultad de Farmacia y Bioquímica, Instituto de Investigaciones en Bacteriología y Virología Molecular (IBaViM), Universidad de Buenos Aires, Buenos Aires, Argentina.,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Daniela M Fidalgo
- Laboratorio de Química Medicinal, Centro de Investigaciones en Bionanociencias (CIBION)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Natalia S Adler
- Laboratorio de Química Medicinal, Centro de Investigaciones en Bionanociencias (CIBION)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Leandro Battini
- Laboratorio de Química Medicinal, Centro de Investigaciones en Bionanociencias (CIBION)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Maria J España de Marco
- Departamento de Microbiología, Inmunología, Biotecnología y Genética, Cátedra Virología, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Matias Fabiani
- Departamento de Microbiología, Inmunología, Biotecnología y Genética, Cátedra Virología, Facultad de Farmacia y Bioquímica, Instituto de Investigaciones en Bacteriología y Virología Molecular (IBaViM), Universidad de Buenos Aires, Buenos Aires, Argentina.,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Ana M Bruno
- Departamento de Química Orgánica, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Mariela Bollini
- Laboratorio de Química Medicinal, Centro de Investigaciones en Bionanociencias (CIBION)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Lucia V Cavallaro
- Departamento de Microbiología, Inmunología, Biotecnología y Genética, Cátedra Virología, Facultad de Farmacia y Bioquímica, Instituto de Investigaciones en Bacteriología y Virología Molecular (IBaViM), Universidad de Buenos Aires, Buenos Aires, Argentina
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20
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Ahmad M, Dwivedy A, Mariadasse R, Tiwari S, Kar D, Jeyakanthan J, Biswal BK. Prediction of Small Molecule Inhibitors Targeting the Severe Acute Respiratory Syndrome Coronavirus-2 RNA-dependent RNA Polymerase. ACS OMEGA 2020; 5:18356-18366. [PMID: 32743211 PMCID: PMC7391942 DOI: 10.1021/acsomega.0c02096] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 06/30/2020] [Indexed: 05/08/2023]
Abstract
The current COVID-19 outbreak warrants the design and development of novel anti-COVID therapeutics. Using a combination of bioinformatics and computational tools, we modelled the 3D structure of the RdRp (RNA-dependent RNA polymerase) of SARS-CoV2 (severe acute respiratory syndrome coronavirus-2) and predicted its probable GTP binding pocket in the active site. GTP is crucial for the formation of the initiation complex during RNA replication. This site was computationally targeted using a number of small molecule inhibitors of the hepatitis C RNA polymerase reported previously. Further optimizations suggested a lead molecule that may prove fruitful in the development of potent inhibitors against the RdRp of SARS-CoV2.
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Affiliation(s)
- Mohammed Ahmad
- National
Institute of Immunology, New Delhi 110067, India
| | | | - Richard Mariadasse
- Department
of Bioinformatics, Alagappa University, karaikudi 630004, Tamil Nadu, India
| | - Satish Tiwari
- National
Institute of Immunology, New Delhi 110067, India
| | - Deepsikha Kar
- National
Institute of Immunology, New Delhi 110067, India
| | - Jeyaraman Jeyakanthan
- Department
of Bioinformatics, Alagappa University, karaikudi 630004, Tamil Nadu, India
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21
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Khalid H, Landry KB, Ijaz B, Ashfaq UA, Ahmed M, Kanwal A, Froeyen M, Mirza MU. Discovery of novel Hepatitis C virus inhibitor targeting multiple allosteric sites of NS5B polymerase. INFECTION GENETICS AND EVOLUTION 2020; 84:104371. [PMID: 32485331 DOI: 10.1016/j.meegid.2020.104371] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2020] [Revised: 05/13/2020] [Accepted: 05/18/2020] [Indexed: 02/07/2023]
Abstract
HCV is a viral infection posing a severe global threat when left untreated progress to end-stage liver disease, including cirrhosis and HCC. The NS5B polymerase of HCV is the most potent target that harbors four allosteric binding sites that could interfere with the HCV infection. We present the discovery of a novel synthetic compound that harbors the potential of NS5B polymerase inhibition. All eight compounds belonging to the benzothiazine family of heterocycles displayed no cellular cytotoxicity in HepG2 cells at nontoxic dose concentration (200 μM). Subsequently, among eight compounds of the series, merely compound 5b exhibited significant inhibition of the expression of the HCV NS5B gene as compared to DMSO control in semi-quantitative PCR. Based on our western blot result, 5b at the range of 50, 100 and 200 μM induced 20, 40, and 70% inhibition of NS5B protein respectively. To estimate the binding potential, 5b was docked at respective allosteric sites followed by molecular dynamics (MD) simulations for a period of 20 ns. In addition, binding free energy calculation by MM-GB/PBSA method revealed a conserved interaction profile of residues lining the allosteric sites in agreement with the reported NS5B co-crystallized inhibitors. The presented results provide important information about a novel compound 5b which may facilitate the the discovery of novel inhibitors that tends to target multiple sites on NS5B polymerase.
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Affiliation(s)
- Hina Khalid
- Department of Bioinformatics and Biotechnology, Government College University, 38000 Faisalabad, Pakistan
| | - Koloko Brice Landry
- Center of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Bushra Ijaz
- Center of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Usman Ali Ashfaq
- Department of Bioinformatics and Biotechnology, Government College University, 38000 Faisalabad, Pakistan.
| | - Matloob Ahmed
- Department of Chemistry, Government College University, 38000 Faisalabad, Pakistan
| | - Afshan Kanwal
- Department of Chemistry, Government College University, 38000 Faisalabad, Pakistan
| | - Matheus Froeyen
- Department of Pharmaceutical Sciences, REGA Institute for Medical Research, Medicinal Chemistry, University of Leuven, 3000 Leuven, Belgium
| | - Muhammad Usman Mirza
- Department of Pharmaceutical Sciences, REGA Institute for Medical Research, Medicinal Chemistry, University of Leuven, 3000 Leuven, Belgium
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22
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Applying a pan-flavivirus RT-qPCR assay in Brazilian public health surveillance. Arch Virol 2020; 165:1863-1868. [PMID: 32474687 DOI: 10.1007/s00705-020-04680-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Accepted: 04/24/2020] [Indexed: 10/24/2022]
Abstract
The aim of this study was to improve flavivirus field monitoring in Brazil using a reliable probe-based RT-qPCR assay. Standard flavivirus strains were employed to evaluate the performance of the assay, and its applicability was evaluated using 235 stored pools of Culicidae samples collected between 1993 and 1997 and in 2016. Flavivirus species were identified by sequencing. Sixteen (6.8%) samples tested positive: Ilheus virus, Iguape virus, and Saint Louis encephalitis virus were identified in historical specimens from 1993-1994, while insect-specific flaviviruses were detected in the samples from 2016. This approach was demonstrated to be accurate for flavivirus detection and characterization, and it can be successfully applied for vector surveillance and for monitoring and discovery of insect specific flaviviruses.
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23
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Recombinant E rns-E2 protein vaccine formulated with MF59 and CPG-ODN promotes T cell immunity against bovine viral diarrhea virus infection. Vaccine 2020; 38:3881-3891. [PMID: 32280039 DOI: 10.1016/j.vaccine.2020.03.020] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Revised: 03/02/2020] [Accepted: 03/06/2020] [Indexed: 02/07/2023]
Abstract
To obtain an effective vaccine candidate against bovine viral diarrhea virus (BVDV) disease which causes great economical loss in cattle industries, recombinant Erns-E2 protein vaccine containing MF59 and CPG-ODN adjuvants was prepared and assessed in this study. The recombinant plasmid (pET32a-Erns-E2) was constructed and transformed into BL21 (DE3) cells to produce Erns-E2 protein. We immunized mice with the MF59-and CPG-ODN-adjuvanted recombinant Erns-E2 protein, E2 protein, or Erns protein, respectively. To evaluate immunogenicity and efficacy of a vaccine-adjuvant combination, mice were challenged with BVDV BJ175170 strain after immunization. All adjuvanted vaccines elicited detectable humoral and cellular immune responses, the BVDV-specific antibody titers as well as interleukin 4 (IL-4) levels in sera of mice immunized with the recombinant Erns-E2 protein were higher than in those of mice immunized with either the recombinant Erns or E2 protein. Besides, immunization with the Erns-E2 vaccines induced higher percentage of CD4+IFN-γ+, CD8+IFN-γ+ T cells and CD3+TNF-α+ T cells compared with the other vaccines. More protective efficacy against BVDV infection was acquired in the mice treated with the recombinant Erns-E2 protein, as shown by a reduction of viremia and slight pathological changes compared with both the control mice and the other vaccinated mice. Our findings suggest that the use of the recombinant Erns-E2 protein vaccine formulated with MF59 and CPG-ODN adjuvants enhances T cell responses and viral control, which warrants the Erns-E2 protein vaccine-adjuvant combination could be as a vaccine strategy to against BVDV.
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Musiu S, Castillo YP, Muigg A, Pürstinger G, Leyssen P, Froeyen M, Neyts J, Paeshuyse J. Quinolinecarboxamides Inhibit the Replication of the Bovine Viral Diarrhea Virus by Targeting a Hot Spot for the Inhibition of Pestivirus Replication in the RNA-Dependent RNA Polymerase. Molecules 2020; 25:molecules25061283. [PMID: 32178258 PMCID: PMC7144022 DOI: 10.3390/molecules25061283] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 03/06/2020] [Accepted: 03/10/2020] [Indexed: 11/16/2022] Open
Abstract
The bovine viral diarrhea virus (BVDV), a pestivirus from the family of Flaviviridae is ubiquitous and causes a range of clinical manifestations in livestock, mainly cattle. Two quinolinecarboxamide analogues were identified in a CPE-based screening effort, as selective inhibitors of the in vitro bovine viral diarrhea virus (BVDV) replication, i.e., TO505-6180/CSFCI (average EC50 = 0.07 µM, SD = 0.02 µM, CC50 > 100 µM) and TO502-2403/CSFCII (average EC50 = 0.2 µM, SD = 0.06 µM, CC50 > 100 µM). The initial antiviral activity observed for both hits against BVDV was corroborated by measuring the inhibitory effect on viral RNA synthesis and the production of infectious virus. Modification of the substituents on the quinolinecarboxamide scaffold resulted in analogues that proved about 7-fold more potent (average EC50 = 0.03 with a SD = 0.01 µM) and that were devoid of cellular toxicity, for the concentration range tested (SI = 3333). CSFCII resistant BVDV variants were selected and were found to carry the F224P mutation in the viral RNA-dependent RNA polymerase (RdRp), whereas CSFCI resistant BVDV carried two mutations in the same region of the RdRp, i.e., N264D and F224Y. Likewise, molecular modeling revealed that F224P/Y and N264D are located in a small cavity near the fingertip domain of the pestivirus polymerase. CSFC-resistant BVDV proved to be cross-resistant to earlier reported pestivirus inhibitors (BPIP, AG110, LZ37, and BBP) that are known to target the same region of the RdRp. CSFC analogues did not inhibit the in vitro activity of recombinant BVDV RdRp but inhibited the activity of BVDV replication complexes (RCs). CSFC analogues likely interact with the fingertip of the pestivirus RdRp at the same position as BPIP, AG110, LZ37, and BBP. This indicates that this region is a “hot spot” for the inhibition of pestivirus replication.
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Affiliation(s)
- Simone Musiu
- KU Leuven University, Department of Microbiology and Immunology, Laboratory of Virology and Chemotherapy, Rega Institute for Medical Research, Leuven, Herestraat 49, B-3000 Leuven, Belgium
| | - Yunierkis Perez Castillo
- Bio-Cheminformatics Research Group and Escuela de Ciencias Físicas y Matemáticas, Universidad de Las Americas, 170150 Quito, Ecuador
| | - Alexandra Muigg
- Institut für Pharmazie, Abteilung Pharmazeutische Chemie, Universität Innsbruck, Innrain 80/82, A-6020 Innsbruck, Austria
| | - Gerhard Pürstinger
- Institut für Pharmazie, Abteilung Pharmazeutische Chemie, Universität Innsbruck, Innrain 80/82, A-6020 Innsbruck, Austria
| | - Pieter Leyssen
- KU Leuven University, Department of Microbiology and Immunology, Laboratory of Virology and Chemotherapy, Rega Institute for Medical Research, Leuven, Herestraat 49, B-3000 Leuven, Belgium
| | - Mathy Froeyen
- KU Leuven University, Department of Pharmaceutical and Pharmacological Sciences, Laboratory of Medicinal Chemistry, Rega Institute for Medical Research, Leuven, Herestraat 49, B-3000 Leuven, Belgium
| | - Johan Neyts
- KU Leuven University, Department of Microbiology and Immunology, Laboratory of Virology and Chemotherapy, Rega Institute for Medical Research, Leuven, Herestraat 49, B-3000 Leuven, Belgium
| | - Jan Paeshuyse
- KU Leuven, Division Animal and Human Health Engineering, Laboratory for host pathogen interactions, Kasteelpark Arenberg 30, 3001 Leuven, Belgium
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Cao D, Gao Y, Roesler C, Rice S, D'Cunha P, Zhuang L, Slack J, Domke M, Antonova A, Romanelli S, Keating S, Forero G, Juneja P, Liang B. Cryo-EM structure of the respiratory syncytial virus RNA polymerase. Nat Commun 2020; 11:368. [PMID: 31953395 PMCID: PMC6969064 DOI: 10.1038/s41467-019-14246-3] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 12/18/2019] [Indexed: 12/21/2022] Open
Abstract
The respiratory syncytial virus (RSV) RNA polymerase, constituted of a 250 kDa large (L) protein and tetrameric phosphoprotein (P), catalyzes three distinct enzymatic activities — nucleotide polymerization, cap addition, and cap methylation. How RSV L and P coordinate these activities is poorly understood. Here, we present a 3.67 Å cryo-EM structure of the RSV polymerase (L:P) complex. The structure reveals that the RNA dependent RNA polymerase (RdRp) and capping (Cap) domains of L interact with the oligomerization domain (POD) and C-terminal domain (PCTD) of a tetramer of P. The density of the methyltransferase (MT) domain of L and the N-terminal domain of P (PNTD) is missing. Further analysis and comparison with other RNA polymerases at different stages suggest the structure we obtained is likely to be at an elongation-compatible stage. Together, these data provide enriched insights into the interrelationship, the inhibitors, and the evolutionary implications of the RSV polymerase. Respiratory syncytial virus (RSV) is a pathogenic non-segmented negative-sense RNA virus and active RSV polymerase is composed of a 250 kDa large (L) protein and tetrameric phosphoprotein (P). Here, the authors present the 3.67 Å cryo-EM structure of the RSV polymerase (L:P) complex.
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Affiliation(s)
- Dongdong Cao
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Yunrong Gao
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Claire Roesler
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Samantha Rice
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Paul D'Cunha
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Lisa Zhuang
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Julia Slack
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Mason Domke
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Anna Antonova
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Sarah Romanelli
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Shayon Keating
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Gabriela Forero
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Puneet Juneja
- Robert P. Apkarian Integrated Electron Microscopy Core, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Bo Liang
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, 30322, USA.
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Tomar S, Mahajan S, Kumar R. Advances in structure-assisted antiviral discovery for animal viral diseases. GENOMICS AND BIOTECHNOLOGICAL ADVANCES IN VETERINARY, POULTRY, AND FISHERIES 2020. [PMCID: PMC7149589 DOI: 10.1016/b978-0-12-816352-8.00019-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Duan H, Ma Z, Xu L, Zhang A, Li Z, Xiao S. A novel intracellularly expressed NS5B-specific nanobody suppresses bovine viral diarrhea virus replication. Vet Microbiol 2019; 240:108449. [PMID: 31836380 PMCID: PMC7117317 DOI: 10.1016/j.vetmic.2019.108449] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 09/29/2019] [Accepted: 10/06/2019] [Indexed: 12/16/2022]
Abstract
BVDV NS5B-specific nanobodies were identified. NS5B-specific nanobody Nb1 suppresses BVDV infection and replication. Nb1 interacts with NS5B protein during BVDV infection.
Bovine viral diarrhea virus (BVDV) infection causes significant economic losses to the cattle industry worldwide and still represents a huge pressure on agricultural production. Thus, the development of novel anti-BVDV strategies are urgently needed. The nonstructural protein 5 (NS5B) of BVDV is essential for viral replication. Further, the camel single-domain antibody (nanobody) represents a promising antiviral approach with the advantages of small size, stable structure, high specificity and solubility, and the recognition of specific epitopes. However, no NS5B-specific nanobodies against BVDV have been reported. In this study, NS5B-specific nanobodies were isolated from a phage display library of variable domains of Camellidae heavy chain-only antibodies (VHHs). Further, an MDBK cell line stably expressing Nb1 was established to explore antiviral activity. Results showed that Nb1 could markedly suppress BVDV replication and interact with the BVDV NS5B protein. This suggests that nanobodies have potential for the development of novel antiviral drugs against BVDV infection.
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Affiliation(s)
- Hong Duan
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, 712100, China.
| | - Zhiqian Ma
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, 712100, China.
| | - Lele Xu
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, 712100, China.
| | - Angke Zhang
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, 712100, China; College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou, Henan, 450046, China.
| | - Zhiwei Li
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, 712100, China.
| | - Shuqi Xiao
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, 712100, China.
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Gilman MSA, Liu C, Fung A, Behera I, Jordan P, Rigaux P, Ysebaert N, Tcherniuk S, Sourimant J, Eléouët JF, Sutto-Ortiz P, Decroly E, Roymans D, Jin Z, McLellan JS. Structure of the Respiratory Syncytial Virus Polymerase Complex. Cell 2019; 179:193-204.e14. [PMID: 31495574 PMCID: PMC7111336 DOI: 10.1016/j.cell.2019.08.014] [Citation(s) in RCA: 87] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 08/03/2019] [Accepted: 08/06/2019] [Indexed: 01/29/2023]
Abstract
Numerous interventions are in clinical development for respiratory syncytial virus (RSV) infection, including small molecules that target viral transcription and replication. These processes are catalyzed by a complex comprising the RNA-dependent RNA polymerase (L) and the tetrameric phosphoprotein (P). RSV P recruits multiple proteins to the polymerase complex and, with the exception of its oligomerization domain, is thought to be intrinsically disordered. Despite their critical roles in RSV transcription and replication, structures of L and P have remained elusive. Here, we describe the 3.2-Å cryo-EM structure of RSV L bound to tetrameric P. The structure reveals a striking tentacular arrangement of P, with each of the four monomers adopting a distinct conformation. The structure also rationalizes inhibitor escape mutants and mutations observed in live-attenuated vaccine candidates. These results provide a framework for determining the molecular underpinnings of RSV replication and transcription and should facilitate the design of effective RSV inhibitors.
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Affiliation(s)
- Morgan S A Gilman
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA
| | - Cheng Liu
- Janssen BioPharma, Inc., Janssen Pharmaceutical Companies, South San Francisco, CA 94080, USA
| | - Amy Fung
- Janssen BioPharma, Inc., Janssen Pharmaceutical Companies, South San Francisco, CA 94080, USA
| | - Ishani Behera
- Janssen BioPharma, Inc., Janssen Pharmaceutical Companies, South San Francisco, CA 94080, USA
| | - Paul Jordan
- Janssen BioPharma, Inc., Janssen Pharmaceutical Companies, South San Francisco, CA 94080, USA
| | - Peter Rigaux
- Janssen Infectious Diseases and Vaccines, 2340 Beerse, Belgium
| | - Nina Ysebaert
- Janssen Infectious Diseases and Vaccines, 2340 Beerse, Belgium
| | - Sergey Tcherniuk
- Unité de Virologie et Immunologie Moléculaires, INRA, Université Paris Saclay, 78350 Jouy en Josas, France
| | - Julien Sourimant
- Unité de Virologie et Immunologie Moléculaires, INRA, Université Paris Saclay, 78350 Jouy en Josas, France
| | - Jean-François Eléouët
- Unité de Virologie et Immunologie Moléculaires, INRA, Université Paris Saclay, 78350 Jouy en Josas, France
| | | | - Etienne Decroly
- Aix Marseille Université, CNRS, AFMB UMR 7257, Marseille, France
| | - Dirk Roymans
- Janssen Infectious Diseases and Vaccines, 2340 Beerse, Belgium
| | - Zhinan Jin
- Janssen BioPharma, Inc., Janssen Pharmaceutical Companies, South San Francisco, CA 94080, USA
| | - Jason S McLellan
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA.
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29
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Determination of Critical Requirements for Classical Swine Fever Virus NS2-3-Independent Virion Formation. J Virol 2019; 93:JVI.00679-19. [PMID: 31292243 DOI: 10.1128/jvi.00679-19] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Accepted: 06/27/2019] [Indexed: 01/07/2023] Open
Abstract
For members of the Flaviviridae, it is known that, besides the structural proteins, nonstructural (NS) proteins also play a critical role in virion formation. Pestiviruses, such as bovine viral diarrhea virus (BVDV), rely on uncleaved NS2-3 for virion formation, while its cleavage product, NS3, is selectively active in RNA replication. This dogma was recently challenged by the selection of gain-of-function mutations in NS2 and NS3 which allowed virion formation in the absence of uncleaved NS2-3 in BVDV type 1 (BVDV-1) variants encoding either a ubiquitin (Ubi) (NS2-Ubi-NS3) or an internal ribosome entry site (IRES) (NS2-IRES-NS3) between NS2 and NS3. To determine whether the ability to adapt to NS2-3-independent virion morphogenesis is conserved among pestiviruses, we studied the corresponding NS2 and NS3 mutations (2/T444-V and 3/M132-A) in classical swine fever virus (CSFV). We observed that these mutations were capable of restoring low-level NS2-3-independent virion formation only for CSFV NS2-Ubi-NS3. Interestingly, a second NS2 mutation (V439-D), identified by selection, was essential for high-titer virion production. Similar to previous findings for BVDV-1, these mutations in NS2 and NS3 allowed for low-titer virion production only in CSFV NS2-IRES-NS3. For efficient virion morphogenesis, additional exchanges in NS4A (A48-T) and NS5B (D280-G) were required, indicating that these proteins cooperate in NS2-3-independent virion formation. Interestingly, both NS5B mutations, selected independently for NS2-IRES-NS3 variants of BVDV-1 and CSFV, are located in the fingertip region of the viral RNA-dependent RNA polymerase, classifying this structural element as a novel determinant for pestiviral NS2-3-independent virion formation. Together, these findings will stimulate further mechanistic studies on the genome packaging of pestiviruses.IMPORTANCE For Flaviviridae members, the nonstructural proteins are essential for virion formation and thus exert a dual role in RNA replication and virion morphogenesis. However, it remains unclear how these proteins are functionalized for either process. In wild-type pestiviruses, the NS3/4A complex is selectively active in RNA replication, while NS2-3/4A is essential for virion formation. Mutations recently identified in BVDV-1 rendered NS3/4A capable of supporting NS2-3-independent virion morphogenesis. A comparison of NS3/4A complexes incapable/capable of supporting virion morphogenesis revealed that changes in NS3/NS4A surface interactions are decisive for the gain of function. However, so far, the role of the NS2 mutations as well as the accessory mutations additionally required in the NS2-IRES-NS3 virus variant has not been clarified. To unravel the course of genome packaging, the additional sets of mutations obtained for a second pestivirus species (CSFV) are of significant importance to develop mechanistic models for this complex process.
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30
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Jia H, Gong P. A Structure-Function Diversity Survey of the RNA-Dependent RNA Polymerases From the Positive-Strand RNA Viruses. Front Microbiol 2019; 10:1945. [PMID: 31507560 PMCID: PMC6713929 DOI: 10.3389/fmicb.2019.01945] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 08/07/2019] [Indexed: 01/15/2023] Open
Abstract
The RNA-dependent RNA polymerases (RdRPs) encoded by the RNA viruses are a unique class of nucleic acid polymerases. Each viral RdRP contains a 500–600 residue catalytic module with palm, fingers, and thumb domains forming an encircled human right hand architecture. Seven polymerase catalytic motifs are located in the RdRP palm and fingers domains, comprising the most conserved parts of the RdRP and are responsible for the RNA-only specificity in catalysis. Functional regions are often found fused to the RdRP catalytic module, resulting in a high level of diversity in RdRP global structure and regulatory mechanism. In this review, we surveyed all 46 RdRP-sequence available virus families of the positive-strand RNA viruses listed in the 2018b collection of the International Committee on Virus Taxonomy (ICTV) and chose a total of 49 RdRPs as representatives. By locating hallmark residues in RdRP catalytic motifs and by referencing structural and functional information in the literature, we were able to estimate the N- and C-terminal boundaries of the catalytic module in these RdRPs, which in turn serve as reference points to predict additional functional regions beyond the catalytic module. Interestingly, a large number of virus families may have additional regions fused to the RdRP N-terminus, while only a few of them have such regions on the C-terminal side of the RdRP. The current knowledge on these additional regions, either in three-dimensional (3D) structure or in function, is quite limited. In the five RdRP-structure available virus families in the positive-strand RNA viruses, only the Flaviviridae family has the 3D structural information resolved for such regions. Hence, future efforts to solve full-length RdRP structures containing these regions and to dissect the functional contribution of them are necessary to improve the overall understanding of the RdRP proteins as an evolutionarily integrated group, and our analyses here may serve as a guideline for selecting representative RdRP systems in these studies.
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Affiliation(s)
- Hengxia Jia
- Key Laboratory of Special Pathogens and Biosafety, Center for Biosafety Mega-Science, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Peng Gong
- Key Laboratory of Special Pathogens and Biosafety, Center for Biosafety Mega-Science, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
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31
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Cressey TN, Noton SL, Nagendra K, Braun MR, Fearns R. Mechanism for de novo initiation at two sites in the respiratory syncytial virus promoter. Nucleic Acids Res 2019; 46:6785-6796. [PMID: 29873775 PMCID: PMC6061868 DOI: 10.1093/nar/gky480] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Accepted: 05/17/2018] [Indexed: 12/18/2022] Open
Abstract
The respiratory syncytial virus (RSV) RNA dependent RNA polymerase (RdRp) initiates two RNA synthesis processes from the viral promoter: genome replication from position 1U and mRNA transcription from position 3C. Here, we examined the mechanism by which a single promoter can direct initiation from two sites. We show that initiation at 1U and 3C occurred independently of each other, and that the same RdRp was capable of precisely selecting the two sites. The RdRp preferred to initiate at 3C, but initiation site selection could be modulated by the relative concentrations of ATP versus GTP. Analysis of template mutations indicated that the RdRp could bind ATP and CTP, or GTP, independently of template nucleotides. The data suggest a model in which innate affinity of the RdRp for particular NTPs, coupled with a repeating element within the promoter, allows precise initiation of replication at 1U or transcription at 3C.
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Affiliation(s)
- Tessa N Cressey
- Department of Microbiology, Boston University School of Medicine, Boston, MA 02118, USA
| | - Sarah L Noton
- Department of Microbiology, Boston University School of Medicine, Boston, MA 02118, USA
| | - Kartikeya Nagendra
- Department of Microbiology, Boston University School of Medicine, Boston, MA 02118, USA
| | - Molly R Braun
- Department of Microbiology, Boston University School of Medicine, Boston, MA 02118, USA
| | - Rachel Fearns
- Department of Microbiology, Boston University School of Medicine, Boston, MA 02118, USA
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Ogino T, Green TJ. RNA Synthesis and Capping by Non-segmented Negative Strand RNA Viral Polymerases: Lessons From a Prototypic Virus. Front Microbiol 2019; 10:1490. [PMID: 31354644 PMCID: PMC6636387 DOI: 10.3389/fmicb.2019.01490] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 06/14/2019] [Indexed: 12/26/2022] Open
Abstract
Non-segmented negative strand (NNS) RNA viruses belonging to the order Mononegavirales are highly diversified eukaryotic viruses including significant human pathogens, such as rabies, measles, Nipah, and Ebola. Elucidation of their unique strategies to replicate in eukaryotic cells is crucial to aid in developing anti-NNS RNA viral agents. Over the past 40 years, vesicular stomatitis virus (VSV), closely related to rabies virus, has served as a paradigm to study the fundamental molecular mechanisms of transcription and replication of NNS RNA viruses. These studies provided insights into how NNS RNA viruses synthesize 5'-capped mRNAs using their RNA-dependent RNA polymerase L proteins equipped with an unconventional mRNA capping enzyme, namely GDP polyribonucleotidyltransferase (PRNTase), domain. PRNTase or PRNTase-like domains are evolutionally conserved among L proteins of all known NNS RNA viruses and their related viruses belonging to Jingchuvirales, a newly established order, in the class Monjiviricetes, suggesting that they may have evolved from a common ancestor that acquired the unique capping system to replicate in a primitive eukaryotic host. This article reviews what has been learned from biochemical and structural studies on the VSV RNA biosynthesis machinery, and then focuses on recent advances in our understanding of regulatory and catalytic roles of the PRNTase domain in RNA synthesis and capping.
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Affiliation(s)
- Tomoaki Ogino
- Department of Molecular Biology and Microbiology, Case Western Reserve University School of Medicine, Cleveland, OH, United States
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States
| | - Todd J. Green
- Department of Microbiology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
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Mittal L, Srivastava M, Asthana S. Conformational Characterization of Linker Revealed the Mechanism of Cavity Formation by 227G in BVDV RDRP. J Phys Chem B 2019; 123:6150-6160. [DOI: 10.1021/acs.jpcb.9b01859] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Lovika Mittal
- Drug Discovery Research Center (DDRC), Translational Health Science and Technology Institute (THSTI), NCR Biotech Science Cluster, 3rd Milestone, Faridabad−Gurgaon Expressway, Faridabad, Haryana 121001, India
| | - Mitul Srivastava
- Drug Discovery Research Center (DDRC), Translational Health Science and Technology Institute (THSTI), NCR Biotech Science Cluster, 3rd Milestone, Faridabad−Gurgaon Expressway, Faridabad, Haryana 121001, India
| | - Shailendra Asthana
- Drug Discovery Research Center (DDRC), Translational Health Science and Technology Institute (THSTI), NCR Biotech Science Cluster, 3rd Milestone, Faridabad−Gurgaon Expressway, Faridabad, Haryana 121001, India
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Ferrero DS, Ruiz-Arroyo VM, Soler N, Usón I, Guarné A, Verdaguer N. Supramolecular arrangement of the full-length Zika virus NS5. PLoS Pathog 2019; 15:e1007656. [PMID: 30951555 PMCID: PMC6469808 DOI: 10.1371/journal.ppat.1007656] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Revised: 04/17/2019] [Accepted: 02/23/2019] [Indexed: 12/12/2022] Open
Abstract
Zika virus (ZIKV), a member of the Flaviviridae family, has emerged as a major public health threat, since ZIKV infection has been connected to microcephaly and other neurological disorders. Flavivirus genome replication is driven by NS5, an RNA-dependent RNA polymerase (RdRP) that also contains a N-terminal methyltransferase domain essential for viral mRNA capping. Given its crucial roles, ZIKV NS5 has become an attractive antiviral target. Here, we have used integrated structural biology approaches to characterize the supramolecular arrangement of the full-length ZIKV NS5, highlighting the assembly and interfaces between NS5 monomers within a dimeric structure, as well as the dimer-dimer interactions to form higher order fibril-like structures. The relative orientation of each monomer within the dimer provides a model to explain the coordination between MTase and RdRP domains across neighboring NS5 molecules and mutational studies underscore the crucial role of the MTase residues Y25, K28 and K29 in NS5 dimerization. The basic residue K28 also participates in GTP binding and competition experiments indicate that NS5 dimerization is disrupted at high GTP concentrations. This competition represents a first glimpse at a molecular level explaining how dimerization might regulate the capping process. The lack of vaccine or antiviral drugs to combat Zika virus (ZIKV) infection has encouraged scientists to characterize in depth potential drug targets. One attractive candidate is NS5, responsible for the catalysis of the 5’-RNA capping, methylation and RNA synthesis, during flavivirus genome replication. To fulfill these activities, the methyltransferase and RNA-dependent RNA polymerase domains of NS5 need to cooperate with each other. The structural and biophysical data presented in this work demonstrate that the ZIKV NS5 protein has the ability to form dimers, as well as higher order oligomers that may participate in the fine-tuning regulation of the multiple enzyme functions in the replication complex. In addition, we have found that NS5 dimerization is disrupted at high GTP concentrations, explaining how dimerization might regulate the capping process.
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Affiliation(s)
- Diego S. Ferrero
- Structural Biology Unit, Institut de Biología Molecular de Barcelona CSIC, Barcelona, Spain
| | - Victor M. Ruiz-Arroyo
- Structural Biology Unit, Institut de Biología Molecular de Barcelona CSIC, Barcelona, Spain
| | - Nicolas Soler
- Structural Biology Unit, Institut de Biología Molecular de Barcelona CSIC, Barcelona, Spain
| | - Isabel Usón
- Structural Biology Unit, Institut de Biología Molecular de Barcelona CSIC, Barcelona, Spain
- ICREA Institució Catalana de Recerca i Estudis Avançats, Barcelona, Spain
| | - Alba Guarné
- Department of Biochemistry, McGill University, Montreal, Quebec, Canada
| | - Núria Verdaguer
- Structural Biology Unit, Institut de Biología Molecular de Barcelona CSIC, Barcelona, Spain
- * E-mail:
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35
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Castro EF, Casal JJ, de Marco MJE, Battini L, Fabiani M, Fernández GA, Bruno AM, Cavallaro LV, Bollini M. Identification of potent bovine viral diarrhea virus inhibitors by a structure-based virtual screening approach. Bioorg Med Chem Lett 2019; 29:262-266. [PMID: 30501966 DOI: 10.1016/j.bmcl.2018.11.041] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 11/08/2018] [Accepted: 11/21/2018] [Indexed: 10/27/2022]
Abstract
Bovine viral diarrhea virus (BVDV) is a pestivirus whose infection in cattle is globally distributed. The use of antivirals could complement vaccination as a tool of control and reduce economic losses. The RNA-dependent RNA polymerase (RdRp) of the virus is essential for its genome replication and constitutes an attractive target for the identification of antivirals. With the aim of obtaining selective BVDV inhibitors, the crystal structure of BVDV RdRp was used to perform a virtual screening. Approximately 15,000 small molecules from commercial and in-house databases were evaluated and several structurally different compounds were tested in vitro for antiviral activity. Interestingly, of twelve evaluated compounds, five were active and displayed EC50 values in the sub and low-micromolar range. Time of drug addition experiment and measured intracellular BVDV RNA showed that compound 7 act during RNA synthesis. Molecular Dynamics and MM/PBSA calculation were done to characterize the interaction of the most active compounds with RdRp, which will allow future ligand optimization. These studies highlight the use of in silico screening to identify a new class of BVDV inhibitors.
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Affiliation(s)
- Eliana F Castro
- Cátedra de Virología, Departamento de Microbiología, Inmunología y Biotecnología, Consejo Nacional de Investigaciones Científicas y Técnicas, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junín 956, 1113, Ciudad Autónoma de Buenos Aires, Argentina
| | - Juan J Casal
- Laboratorio de Química Medicinal, Centro de Investigaciones en Bionanociencias (CIBION)-CONICET, Ciudad de Buenos Aires, Argentina
| | - María J España de Marco
- Cátedra de Virología, Departamento de Microbiología, Inmunología y Biotecnología, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junín 956, 1113, Ciudad Autónoma de Buenos Aires, Argentina
| | - Leandro Battini
- Laboratorio de Química Medicinal, Centro de Investigaciones en Bionanociencias (CIBION)-CONICET, Ciudad de Buenos Aires, Argentina
| | - Matías Fabiani
- Cátedra de Virología, Departamento de Microbiología, Inmunología y Biotecnología, Consejo Nacional de Investigaciones Científicas y Técnicas, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junín 956, 1113, Ciudad Autónoma de Buenos Aires, Argentina
| | - Gabriela A Fernández
- Laboratorio de Química Medicinal, Centro de Investigaciones en Bionanociencias (CIBION)-CONICET, Ciudad de Buenos Aires, Argentina
| | - Ana M Bruno
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Química Orgánica, Junín 956, C1113AAD, Ciudad Autónoma de Buenos Aires, Argentina
| | - Lucía V Cavallaro
- Cátedra de Virología, Departamento de Microbiología, Inmunología y Biotecnología, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junín 956, 1113, Ciudad Autónoma de Buenos Aires, Argentina.
| | - Mariela Bollini
- Laboratorio de Química Medicinal, Centro de Investigaciones en Bionanociencias (CIBION)-CONICET, Ciudad de Buenos Aires, Argentina.
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Liu W, Shi X, Gong P. A unique intra-molecular fidelity-modulating mechanism identified in a viral RNA-dependent RNA polymerase. Nucleic Acids Res 2018; 46:10840-10854. [PMID: 30239956 PMCID: PMC6237809 DOI: 10.1093/nar/gky848] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Accepted: 09/11/2018] [Indexed: 01/07/2023] Open
Abstract
Typically not assisted by proofreading, the RNA-dependent RNA polymerases (RdRPs) encoded by the RNA viruses may need to independently control its fidelity to fulfill virus viability and fitness. However, the precise mechanism by which the RdRP maintains its optimal fidelity level remains largely elusive. By solving 2.1-2.5 Å resolution crystal structures of the classical swine fever virus (CSFV) NS5B, an RdRP with a unique naturally fused N-terminal domain (NTD), we identified high-resolution intra-molecular interactions between the NTD and the RdRP palm domain. In order to dissect possible regulatory functions of NTD, we designed mutations at residues Y471 and E472 to perturb key interactions at the NTD-RdRP interface. When crystallized, some of these NS5B interface mutants maintained the interface, while the others adopted an 'open' conformation that no longer retained the intra-molecular interactions. Data from multiple in vitro RdRP assays indicated that the perturbation of the NTD-RdRP interactions clearly reduced the fidelity level of the RNA synthesis, while the processivity of the NS5B elongation complex was not affected. Collectively, our work demonstrates an explicit and unique mode of polymerase fidelity modulation and provides a vivid example of co-evolution in multi-domain enzymes.
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Affiliation(s)
- Weichi Liu
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, Hubei 430071, China,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaoling Shi
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, Hubei 430071, China,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Peng Gong
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, Hubei 430071, China,To whom correspondence should be addressed. Tel: +86 27 87197578;
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Crystal Structure of Classical Swine Fever Virus NS5B Reveals a Novel N-Terminal Domain. J Virol 2018; 92:JVI.00324-18. [PMID: 29720518 PMCID: PMC6026734 DOI: 10.1128/jvi.00324-18] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Accepted: 04/23/2018] [Indexed: 01/07/2023] Open
Abstract
Classical swine fever virus (CSFV) is the cause of classical swine fever (CSF). Nonstructural protein 5B (NS5B) is an RNA-dependent RNA polymerase (RdRp) that is a key enzyme initiating viral RNA replication by a de novo mechanism. It is also an attractive target for the development of anti-CSFV drugs. To gain a better understanding of the mechanism of CSFV RNA synthesis, here, we solved the first crystal structure of CSFV NS5B. Our studies show that the CSFV NS5B RdRp contains the characteristic finger, palm, and thumb domains, as well as a unique N-terminal domain (NTD) that has never been observed. Mutagenesis studies on NS5B validated the importance of the NTD in the catalytic activity of this novel RNA-dependent RNA polymerase. Moreover, our results shed light on CSFV infection.IMPORTANCE Pigs are important domesticated animals. However, a highly contagious viral disease named classical swine fever (CSF) causes devastating economic losses. Classical swine fever virus (CSFV), the primary cause of CSF, is a positive-sense single-stranded RNA virus belonging to the genus Pestivirus, family Flaviviridae Genome replication of CSFV depends on an RNA-dependent RNA polymerase (RdRp) known as NS5B. However, the structure of CSFV NS5B has never been reported, and the mechanism of CSFV replication is poorly understood. Here, we solve the first crystal structure of CSFV NS5B and analyze the functions of the characteristic finger, palm, and thumb domains. Additionally, our structure revealed the presence of a novel N-terminal domain (NTD). Biochemical studies demonstrated that the NTD of CSFV NS5B is very important for RdRp activity. Collectively, our studies provide a structural basis for future rational design of anti-CSFV drugs, which is critically important, as no effective anti-CSFV drugs have been developed.
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Venkataraman S, Prasad BVLS, Selvarajan R. RNA Dependent RNA Polymerases: Insights from Structure, Function and Evolution. Viruses 2018; 10:v10020076. [PMID: 29439438 PMCID: PMC5850383 DOI: 10.3390/v10020076] [Citation(s) in RCA: 200] [Impact Index Per Article: 33.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Revised: 01/30/2018] [Accepted: 02/03/2018] [Indexed: 12/11/2022] Open
Abstract
RNA dependent RNA polymerase (RdRp) is one of the most versatile enzymes of RNA viruses that is indispensable for replicating the genome as well as for carrying out transcription. The core structural features of RdRps are conserved, despite the divergence in their sequences. The structure of RdRp resembles that of a cupped right hand and consists of fingers, palm and thumb subdomains. The catalysis involves the participation of conserved aspartates and divalent metal ions. Complexes of RdRps with substrates, inhibitors and metal ions provide a comprehensive view of their functional mechanism and offer valuable insights regarding the development of antivirals. In this article, we provide an overview of the structural aspects of RdRps and their complexes from the Group III, IV and V viruses and their structure-based phylogeny.
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Affiliation(s)
- Sangita Venkataraman
- Department of Biotechnology, Acharya Nagarjuna University, Nagarjuna Nagar, Guntur 522510, India.
| | - Burra V L S Prasad
- Amity Institute of Biotechnology, Amity University Haryana, Manesar, Gurgaon 122413, India.
| | - Ramasamy Selvarajan
- ICAR National Research Centre for Banana, Thayanur Post, Tiruchirapalli 620102, India.
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9-Aminoacridine-based agents impair the bovine viral diarrhea virus (BVDV) replication targeting the RNA-dependent RNA polymerase (RdRp). Bioorg Med Chem 2018; 26:855-868. [PMID: 29325885 DOI: 10.1016/j.bmc.2018.01.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 12/05/2017] [Accepted: 01/03/2018] [Indexed: 11/21/2022]
Abstract
Bovine viral diarrhea virus (BVDV) infection is still a plague that causes important livestock pandemics. Despite the availability of vaccines against BVDV, and the implementation of massive eradication or control programs, this virus still constitutes a serious agronomic burden. Therefore, the alternative approach to combat Pestivirus infections, based on the development of antiviral agents that specifically inhibit the replication of these viruses, is of preeminent actuality and importance. Capitalizing from a long-standing experience in antiviral drug design and development, in this work we present and characterize a series of small molecules based on the 9-aminoacridine scaffold that exhibit potent anti-BVDV activity coupled with low cytotoxicity. The relevant viral protein target - the RNA-dependent RNA polymerase - the binding mode, and the mechanism of action of these new antivirals have been determined by a combination of in vitro (i.e., enzymatic inhibition, isothermal titration calorimetry and site-directed mutagenesis assays) and computational experiments. The overall results obtained confirm that these acridine-based derivatives are promising compounds in the treatment of BVDV infections and, based on the reported structure-activity relationship, can be selected as a starting point for the design of a new generation of improved, safe and selective anti-BVDV agents.
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40
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Abstract
Most emerging and re-emerging human and animal viral diseases are associated with RNA viruses. All these pathogens, with the exception of retroviruses, encode a specialized enzyme called RNA-dependent RNA polymerase (RdRP), which catalyze phosphodiester-bond formation between ribonucleotides (NTPs) in an RNA template-dependent manner. These enzymes function either as single polypeptides or in complex with other viral or host components to transcribe and replicate the viral RNA genome. The structures of RdRPs and RdRP catalytic complexes, currently available for several members of (+) ssRNA, (-)ssRNA and dsRNA virus families, have provided high resolution snapshots of the functional steps underlying replication and transcription of viral RNA genomes and their regulatory mechanisms.
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Affiliation(s)
- Diego Ferrero
- Structural Biology Unit, Institut de Biologia Molecular de Barcelona (IBMB-CSIC), Barcelona, Spain
| | - Cristina Ferrer-Orta
- Structural Biology Unit, Institut de Biologia Molecular de Barcelona (IBMB-CSIC), Barcelona, Spain
| | - Núria Verdaguer
- Structural Biology Unit, Institut de Biologia Molecular de Barcelona (IBMB-CSIC), Barcelona, Spain.
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41
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Netzler NE, Enosi Tuipulotu D, Eltahla AA, Lun JH, Ferla S, Brancale A, Urakova N, Frese M, Strive T, Mackenzie JM, White PA. Broad-spectrum non-nucleoside inhibitors for caliciviruses. Antiviral Res 2017; 146:65-75. [PMID: 28757394 DOI: 10.1016/j.antiviral.2017.07.014] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Revised: 07/19/2017] [Accepted: 07/24/2017] [Indexed: 02/06/2023]
Abstract
Viruses of the Caliciviridae cause significant and sometimes lethal diseases, however despite substantial research efforts, specific antivirals are lacking. Broad-spectrum antivirals could combat multiple viral pathogens, offering a rapid solution when no therapies exist. The RNA-dependent RNA polymerase (RdRp) is an attractive antiviral target as it is essential for viral replication and lacks mammalian homologs. To focus the search for pan-Caliciviridae antivirals, the RdRp was probed with non-nucleoside inhibitors (NNIs) developed against hepatitis C virus (HCV) to reveal both allosteric ligands for structure-activity relationship enhancement, and highly-conserved RdRp pockets for antiviral targeting. The ability of HCV NNIs to inhibit calicivirus RdRp activities was assessed using in vitro enzyme and murine norovirus cell culture assays. Results revealed that three NNIs which bound the HCV RdRp Thumb I (TI) site also inhibited transcriptional activities of six RdRps spanning the Norovirus, Sapovirus and Lagovirus genera of the Caliciviridae. These NNIs included JTK-109 (RdRp inhibition range: IC50 4.3-16.6 μM), TMC-647055 (IC50 range: 18.8-45.4 μM) and Beclabuvir (IC50 range: 23.8->100 μM). In silico studies and site-directed mutagenesis indicated the JTK-109 binding site was within the calicivirus RdRp thumb domain, in a pocket termed Site-B, which is highly-conserved within all calicivirus RdRps. Additionally, RdRp inhibition assays revealed that JTK-109 was antagonistic with the previously reported RdRp inhibitor pyridoxal-5'-phosphate-6-(2'-naphthylazo-6'-nitro-4',8'-disulfonate) tetrasodium salt (PPNDS), that also binds to Site-B. Moreover, like JTK-109, PPNDS was also a potent inhibitor of polymerases from six viruses spanning the three Caliciviridae genera tested (IC50 range: 0.1-2.3 μM). Together, this study demonstrates the potential for de novo development of broad-spectrum antivirals that target the highly-conserved RdRp thumb pocket, Site-B. We also revealed three broad-spectrum HCV NNIs that could be used as antiviral scaffolds for further development against caliciviruses and other viruses.
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Affiliation(s)
- Natalie E Netzler
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Daniel Enosi Tuipulotu
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Auda A Eltahla
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia; School of Medical Sciences, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia
| | - Jennifer H Lun
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Salvatore Ferla
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, United Kingdom
| | - Andrea Brancale
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, United Kingdom
| | - Nadya Urakova
- CSIRO Health and Biosecurity, Canberra, ACT, Australia; Invasive Animals Cooperative Research Centre, University of Canberra, ACT, Australia; Health Research Institute, University of Canberra, ACT, Australia
| | - Michael Frese
- CSIRO Health and Biosecurity, Canberra, ACT, Australia; Invasive Animals Cooperative Research Centre, University of Canberra, ACT, Australia; Health Research Institute, University of Canberra, ACT, Australia; Institute for Applied Ecology, University of Canberra, ACT, Australia
| | - Tanja Strive
- CSIRO Health and Biosecurity, Canberra, ACT, Australia; Health Research Institute, University of Canberra, ACT, Australia; Institute for Applied Ecology, University of Canberra, ACT, Australia
| | - Jason M Mackenzie
- Department of Microbiology and Immunology, School of Biomedical Sciences, University of Melbourne, VIC, Australia; The Peter Doherty Institute for Infection and Immunity, VIC, Australia
| | - Peter A White
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia.
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Piyasena TBH, Setoh YX, Hobson-Peters J, Newton ND, Bielefeldt-Ohmann H, McLean BJ, Vet LJ, Khromykh AA, Hall RA. Infectious DNAs derived from insect-specific flavivirus genomes enable identification of pre- and post-entry host restrictions in vertebrate cells. Sci Rep 2017; 7:2940. [PMID: 28592864 PMCID: PMC5462777 DOI: 10.1038/s41598-017-03120-1] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 04/24/2017] [Indexed: 02/06/2023] Open
Abstract
Flaviviruses such as West Nile virus (WNV), dengue virus and Zika virus are mosquito-borne pathogens that cause significant human diseases. A novel group of insect-specific flaviviruses (ISFs), which only replicate in mosquitoes, have also been identified. However, little is known about the mechanisms of ISF host restriction. We report the generation of infectious cDNA from two Australian ISFs, Parramatta River virus (PaRV) and Palm Creek virus (PCV). Using circular polymerase extension cloning (CPEC) with a modified OpIE2 insect promoter, infectious cDNA was generated and transfected directly into mosquito cells to produce infectious virus indistinguishable from wild-type virus. When infectious PaRV cDNA under transcriptional control of a mammalian promoter was used to transfect mouse embryo fibroblasts, the virus failed to initiate replication even when cell entry steps were by-passed and the type I interferon response was lacking. We also used CPEC to generate viable chimeric viruses between PCV and WNV. Analysis of these hybrid viruses revealed that ISFs are also restricted from replication in vertebrate cells at the point of entry. The approaches described here to generate infectious ISF DNAs and chimeric viruses provide unique tools to further dissect the mechanisms of their host restriction.
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Affiliation(s)
- Thisun B H Piyasena
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, 4072, Queensland, Australia
| | - Yin X Setoh
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, 4072, Queensland, Australia
| | - Jody Hobson-Peters
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, 4072, Queensland, Australia
| | - Natalee D Newton
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, 4072, Queensland, Australia
| | - Helle Bielefeldt-Ohmann
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, 4072, Queensland, Australia
| | - Breeanna J McLean
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, 4072, Queensland, Australia
| | - Laura J Vet
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, 4072, Queensland, Australia
| | - Alexander A Khromykh
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, 4072, Queensland, Australia.
| | - Roy A Hall
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, 4072, Queensland, Australia.
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43
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Amroun A, Priet S, de Lamballerie X, Quérat G. Bunyaviridae RdRps: structure, motifs, and RNA synthesis machinery. Crit Rev Microbiol 2017; 43:753-778. [PMID: 28418734 DOI: 10.1080/1040841x.2017.1307805] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Bunyaviridae family is the largest and most diverse family of RNA viruses. It has more than 350 members divided into five genera: Orthobunyavirus, Phlebovirus, Nairovirus, Hantavirus, and Tospovirus. They are present in the five continents, causing recurrent epidemics, epizootics, and considerable agricultural loss. The genome of bunyaviruses is divided into three segments of negative single-stranded RNA according to their relative size: L (Large), M (Medium) and S (Small) segment. Bunyaviridae RNA-dependent RNA polymerase (RdRp) is encoded by the L segment, and is in charge of the replication and transcription of the viral RNA in the cytoplasm of the infected cell. Viral RdRps share a characteristic right hand-like structure with three subdomains: finger, palm, and thumb subdomains that define the formation of the catalytic cavity. In addition to the N-terminal endonuclease domain, eight conserved motifs (A-H) have been identified in the RdRp of Bunyaviridae. In this review, we have summarized the recent insights from the structural and functional studies of RdRp to understand the roles of different motifs shared by RdRps, the mechanism of viral RNA replication, genome segment packaging by the nucleoprotein, cap-snatching, mRNA transcription, and other RNA mechanisms of bunyaviruses.
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Affiliation(s)
- Abdennour Amroun
- a Faculté de Médecine , UMR "Emergence des Pathologies Virales" (Aix-Marseille University - IRD 190 - Inserm 1207 - EHESP), Fondation IHU Méditerranée Infection, APHM Public Hospitals of Marseille , Marseille , France
| | - Stéphane Priet
- a Faculté de Médecine , UMR "Emergence des Pathologies Virales" (Aix-Marseille University - IRD 190 - Inserm 1207 - EHESP), Fondation IHU Méditerranée Infection, APHM Public Hospitals of Marseille , Marseille , France
| | - Xavier de Lamballerie
- a Faculté de Médecine , UMR "Emergence des Pathologies Virales" (Aix-Marseille University - IRD 190 - Inserm 1207 - EHESP), Fondation IHU Méditerranée Infection, APHM Public Hospitals of Marseille , Marseille , France
| | - Gilles Quérat
- a Faculté de Médecine , UMR "Emergence des Pathologies Virales" (Aix-Marseille University - IRD 190 - Inserm 1207 - EHESP), Fondation IHU Méditerranée Infection, APHM Public Hospitals of Marseille , Marseille , France
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44
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Zhao B, Yi G, Du F, Chuang YC, Vaughan RC, Sankaran B, Kao CC, Li P. Structure and function of the Zika virus full-length NS5 protein. Nat Commun 2017; 8:14762. [PMID: 28345656 PMCID: PMC5378950 DOI: 10.1038/ncomms14762] [Citation(s) in RCA: 125] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Accepted: 01/30/2017] [Indexed: 12/11/2022] Open
Abstract
The recent outbreak of Zika virus (ZIKV) has infected over 1 million people in over 30 countries. ZIKV replicates its RNA genome using virally encoded replication proteins. Nonstructural protein 5 (NS5) contains a methyltransferase for RNA capping and a polymerase for viral RNA synthesis. Here we report the crystal structures of full-length NS5 and its polymerase domain at 3.0 Å resolution. The NS5 structure has striking similarities to the NS5 protein of the related Japanese encephalitis virus. The methyltransferase contains in-line pockets for substrate binding and the active site. Key residues in the polymerase are located in similar positions to those of the initiation complex for the hepatitis C virus polymerase. The polymerase conformation is affected by the methyltransferase, which enables a more efficiently elongation of RNA synthesis in vitro. Overall, our results will contribute to future studies on ZIKV infection and the development of inhibitors of ZIKV replication. Zika virus infection can cause human birth defects and Guillain-Barré syndrome. Here the authors present the structures of the full-length nonstructural protein 5 and its RNA-dependent RNA polymerase domain of Zika virus, which are targets for inhibitors of virus replication.
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Affiliation(s)
- Baoyu Zhao
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843, USA
| | - Guanghui Yi
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana 47405, USA
| | - Fenglei Du
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843, USA
| | - Yin-Chih Chuang
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana 47405, USA
| | - Robert C Vaughan
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana 47405, USA
| | - Banumathi Sankaran
- Molecular Biophysics and Integrated Bioimaging, Berkeley Center for Structural Biology, 1 Cyclotron Road, Lawrence Berkeley National Lab, Berkeley 94720, USA
| | - C Cheng Kao
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana 47405, USA
| | - Pingwei Li
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843, USA
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45
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Veel Pilay KP, Jasamai M, Thayan R, Santhanam J, Syed Hassan S, Yap WB. Nucleoside analogs as potential antiviral agents for dengue virus infections. Med Chem Res 2017. [DOI: 10.1007/s00044-017-1863-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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46
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Lu G, Gong P. A structural view of the RNA-dependent RNA polymerases from the Flavivirus genus. Virus Res 2017; 234:34-43. [PMID: 28131854 DOI: 10.1016/j.virusres.2017.01.020] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Revised: 01/15/2017] [Accepted: 01/22/2017] [Indexed: 12/17/2022]
Abstract
The RNA-dependent RNA polymerase (RdRP) from the Flavivirus genus is naturally fused to a methyltransferase (MTase), and the full-length protein is named nonstructural protein 5 (NS5). Similar to polymerases from other RNA viruses, the flavivirus RdRP has an encircled human right hand architecture with palm, fingers, and thumb domains surrounding its polymerase active site. In contrast to primer-dependent RdRPs that have a spacious front channel to accommodate the template-product RNA duplex, the flavivirus RdRP has a priming element as a thumb domain insertion, partially occupying the front channel to facilitate the de novo initiation process. Seven catalytic motifs A through G have been identified for all viral RdRPs and have highly homologous spatial arrangement around the active site despite low sequence conservation in several motifs if considering all viral families, forming an important basis to the understandings of the common features for viral RdRPs. In the two different global conformations identified in full-length crystal structures of Japanese encephalitis virus (JEV) and Dengue virus (DENV) NS5 proteins, the MTase approaches the RdRP consistently from the backside but its orientation and the interaction details with the RdRP are drastically different. Further investigations are required to clarify the conservation, functional relevance, and relationship of these conformations. Remaining challenges with respect to flavivirus RdRP structure are also discussed.
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Affiliation(s)
- Guoliang Lu
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Chinese Academy of Sciences, No. 44 Xiao Hong Shan, Wuhan, Hubei 430071, China
| | - Peng Gong
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Chinese Academy of Sciences, No. 44 Xiao Hong Shan, Wuhan, Hubei 430071, China.
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47
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Bullard-Feibelman KM, Govero J, Zhu Z, Salazar V, Veselinovic M, Diamond MS, Geiss BJ. The FDA-approved drug sofosbuvir inhibits Zika virus infection. Antiviral Res 2016; 137:134-140. [PMID: 27902933 DOI: 10.1016/j.antiviral.2016.11.023] [Citation(s) in RCA: 179] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Revised: 11/24/2016] [Accepted: 11/24/2016] [Indexed: 01/08/2023]
Abstract
The rapidly expanding Zika virus (ZIKV) epidemic has affected thousands of individuals with severe cases causing Guillain-Barré syndrome, congenital malformations, and microcephaly. Currently, there is no available vaccine or therapy to prevent or treat ZIKV infection. We evaluated whether sofosbuvir, an FDA-approved nucleotide polymerase inhibitor for the distantly related hepatitis C virus, could have antiviral activity against ZIKV infection. Cell culture studies established that sofosbuvir efficiently inhibits replication and infection of several ZIKV strains in multiple human tumor cell lines and isolated human fetal-derived neuronal stem cells. Moreover, oral treatment with sofosbuvir protected against ZIKV-induced death in mice. These results suggest that sofosbuvir may be a candidate for further evaluation as a therapy against ZIKV infection in humans.
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Affiliation(s)
| | - Jennifer Govero
- Department of Medicine, Washington University School of Medicine, Saint Louis, MO, USA
| | - Zhe Zhu
- Department of Stem Cell Biology and Regenerative Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Vanessa Salazar
- Department of Medicine, Washington University School of Medicine, Saint Louis, MO, USA
| | - Milena Veselinovic
- Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO, USA
| | - Michael S Diamond
- Department of Medicine, Washington University School of Medicine, Saint Louis, MO, USA; Department of Pathology and Immunology, Washington University School of Medicine, Saint Louis, MO, USA; Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, MO, USA; The Center for Human Immunology and Immunotherapy Programs, Washington University School of Medicine, Saint Louis, MO, USA
| | - Brian J Geiss
- Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO, USA; School of Biomedical Engineering, Colorado State University, Fort Collins, CO, USA.
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Du Y, Wu NC, Jiang L, Zhang T, Gong D, Shu S, Wu TT, Sun R. Annotating Protein Functional Residues by Coupling High-Throughput Fitness Profile and Homologous-Structure Analysis. mBio 2016; 7:e01801-16. [PMID: 27803181 PMCID: PMC5090041 DOI: 10.1128/mbio.01801-16] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Accepted: 10/07/2016] [Indexed: 11/28/2022] Open
Abstract
Identification and annotation of functional residues are fundamental questions in protein sequence analysis. Sequence and structure conservation provides valuable information to tackle these questions. It is, however, limited by the incomplete sampling of sequence space in natural evolution. Moreover, proteins often have multiple functions, with overlapping sequences that present challenges to accurate annotation of the exact functions of individual residues by conservation-based methods. Using the influenza A virus PB1 protein as an example, we developed a method to systematically identify and annotate functional residues. We used saturation mutagenesis and high-throughput sequencing to measure the replication capacity of single nucleotide mutations across the entire PB1 protein. After predicting protein stability upon mutations, we identified functional PB1 residues that are essential for viral replication. To further annotate the functional residues important to the canonical or noncanonical functions of viral RNA-dependent RNA polymerase (vRdRp), we performed a homologous-structure analysis with 16 different vRdRp structures. We achieved high sensitivity in annotating the known canonical polymerase functional residues. Moreover, we identified a cluster of noncanonical functional residues located in the loop region of the PB1 β-ribbon. We further demonstrated that these residues were important for PB1 protein nuclear import through the interaction with Ran-binding protein 5. In summary, we developed a systematic and sensitive method to identify and annotate functional residues that are not restrained by sequence conservation. Importantly, this method is generally applicable to other proteins about which homologous-structure information is available. IMPORTANCE To fully comprehend the diverse functions of a protein, it is essential to understand the functionality of individual residues. Current methods are highly dependent on evolutionary sequence conservation, which is usually limited by sampling size. Sequence conservation-based methods are further confounded by structural constraints and multifunctionality of proteins. Here we present a method that can systematically identify and annotate functional residues of a given protein. We used a high-throughput functional profiling platform to identify essential residues. Coupling it with homologous-structure comparison, we were able to annotate multiple functions of proteins. We demonstrated the method with the PB1 protein of influenza A virus and identified novel functional residues in addition to its canonical function as an RNA-dependent RNA polymerase. Not limited to virology, this method is generally applicable to other proteins that can be functionally selected and about which homologous-structure information is available.
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Affiliation(s)
- Yushen Du
- Department of Molecular and Medical Pharmacology, University of California Los Angeles, Los Angeles, California, USA
- Cancer Institute, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, ZJU-UCLA Joint Center for Medical Education and Research, Zhejiang University School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Nicholas C Wu
- Department of Molecular and Medical Pharmacology, University of California Los Angeles, Los Angeles, California, USA
- Molecular Biology Institute, University of California Los Angeles, Los Angeles, California, USA
| | - Lin Jiang
- Department of Neurology, University of California Los Angeles, Los Angeles, California, USA
| | - Tianhao Zhang
- Department of Molecular and Medical Pharmacology, University of California Los Angeles, Los Angeles, California, USA
- Molecular Biology Institute, University of California Los Angeles, Los Angeles, California, USA
| | - Danyang Gong
- Department of Molecular and Medical Pharmacology, University of California Los Angeles, Los Angeles, California, USA
| | - Sara Shu
- Department of Molecular and Medical Pharmacology, University of California Los Angeles, Los Angeles, California, USA
| | - Ting-Ting Wu
- Department of Molecular and Medical Pharmacology, University of California Los Angeles, Los Angeles, California, USA
| | - Ren Sun
- Department of Molecular and Medical Pharmacology, University of California Los Angeles, Los Angeles, California, USA
- Cancer Institute, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, ZJU-UCLA Joint Center for Medical Education and Research, Zhejiang University School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
- Molecular Biology Institute, University of California Los Angeles, Los Angeles, California, USA
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Miyamura T, Lemon SM, Walker CM, Wakita T. The HCV Replicase Complex and Viral RNA Synthesis. HEPATITIS C VIRUS I 2016. [PMCID: PMC7122888 DOI: 10.1007/978-4-431-56098-2_8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Replication of hepatitis C virus (HCV) is tightly linked to membrane alterations designated the membranous web, harboring the viral replicase complex. In this chapter we describe the morphology and 3D architecture of the HCV-induced replication organelles, mainly consisting of double membrane vesicles, which are generated by a concerted action of the nonstructural proteins NS3 to NS5B. Recent studies have furthermore identified a number of host cell proteins and lipids contributing to the biogenesis of the membranous web, which are discussed in this chapter. Viral RNA synthesis is tightly associated with these membrane alterations and mainly driven by the viral RNA dependent RNA polymerase NS5B. We summarize our current knowledge of the structure and function of NS5B, the role of cis-acting replication elements at the termini of the genome in regulating RNA synthesis and the contribution of additional viral and host factors to viral RNA synthesis, which is still ill defined.
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Affiliation(s)
- Tatsuo Miyamura
- National Institute of Infectious Diseases, Tokyo, Tokyo Japan
| | - Stanley M. Lemon
- Departments of Medicine and Microbiology & Immunology , The University of North Carolina, Chapel Hill, North Carolina USA
| | - Christopher M. Walker
- Center for Vaccines and Immunity, The Research Institute at Nationwide Children's Hospital, Columbus, Ohio USA
| | - Takaji Wakita
- National Institute of Infectious Diseases, Tokyo, Tokyo Japan
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Valdés JJ, Gil VA, Butterill PT, Růžek D. An all-atom, active site exploration of antiviral drugs that target Flaviviridae polymerases. J Gen Virol 2016; 97:2552-2565. [PMID: 27489039 DOI: 10.1099/jgv.0.000569] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Natural 2'-modified nucleosides are the most widely used antiviral therapy. In their triphosphorylated form, also known as nucleotide analogues, they target the active site of viral polymerases. Viral polymerases have an overall right-handed structure that includes the palm, fingers and thumb domains. These domains are further subdivided into structurally conserved motifs A-G, common to all viral polymerases. The structural motifs encapsulate the allosteric/initiation (N1) and orthosteric/catalytic (N2) nucleotide-binding sites. The current study investigated how nucleotide analogues explore the N2 site of viral polymerases from three genera of the family Flaviviridae using a stochastic, biophysical, Metropolis Monte Carlo-based software. The biophysical simulations showed a statistical distinction in nucleotide-binding energy and exploration between phylogenetically related viral polymerases. This distinction is clearly demonstrated by the respective analogue contacts made with conserved viral polymerase residues, the heterogeneous dynamics of structural motifs, and the orientation of the nucleotide analogues within the N2 site. Being able to simulate what occurs within viral-polymerase-binding sites can prove useful in rational drug designs against viruses.
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Affiliation(s)
- James J Valdés
- Institute of Parasitology, Czech Academy of Sciences, Branišovská 31, CZ-37005 České Budějovice, Czech Republic
- Department of Virology, Veterinary Research Institute, Hudcova 70, CZ-62100 Brno, Czech Republic
| | - Victor A Gil
- Joint BSC-CRG-IRB Research Program in Computational Biology, Barcelona Supercomputing Center, Jordi Girona 29, 08034 Barcelona, Spain
| | - Philip T Butterill
- Biology Center, Czech Academy of Sciences, University of South Bohemia, Branišovská 31, CZ-37005 České Budějovice, Czech Republic
| | - Daniel Růžek
- Institute of Parasitology, Czech Academy of Sciences, Branišovská 31, CZ-37005 České Budějovice, Czech Republic
- Department of Virology, Veterinary Research Institute, Hudcova 70, CZ-62100 Brno, Czech Republic
- Biology Center, Czech Academy of Sciences, University of South Bohemia, Branišovská 31, CZ-37005 České Budějovice, Czech Republic
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