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Chen Y, Kokic G, Dienemann C, Dybkov O, Urlaub H, Cramer P. Structure of the transcribing RNA polymerase II-Elongin complex. Nat Struct Mol Biol 2023; 30:1925-1935. [PMID: 37932450 PMCID: PMC10716050 DOI: 10.1038/s41594-023-01138-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Accepted: 09/26/2023] [Indexed: 11/08/2023]
Abstract
Elongin is a heterotrimeric elongation factor for RNA polymerase (Pol) II transcription that is conserved among metazoa. Here, we report three cryo-EM structures of human Elongin bound to transcribing Pol II. The structures show that Elongin subunit ELOA binds the RPB2 side of Pol II and anchors the ELOB-ELOC subunit heterodimer. ELOA contains a 'latch' that binds between the end of the Pol II bridge helix and funnel helices, thereby inducing a conformational change near the polymerase active center. The latch is required for the elongation-stimulatory activity of Elongin, but not for Pol II binding, indicating that Elongin functions by allosterically regulating the conformational mobility of the polymerase active center. Elongin binding to Pol II is incompatible with association of the super elongation complex, PAF1 complex and RTF1, which also contain an elongation-stimulatory latch element.
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Affiliation(s)
- Ying Chen
- Department of Molecular Biology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- Department of Clinical Laboratory, Qilu Hospital of Shandong University, Jinan, China
| | - Goran Kokic
- Department of Molecular Biology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Christian Dienemann
- Department of Molecular Biology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Olexandr Dybkov
- Bioanalytical Mass Spectrometry, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Henning Urlaub
- Bioanalytical Mass Spectrometry, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- University Medical Center Göttingen, Institute of Clinical Chemistry, Bioanalytics Group, Göttingen, Germany
- Cluster of Excellence 'Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells' (MBExC), University of Göttingen, Göttingen, Germany
| | - Patrick Cramer
- Department of Molecular Biology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany.
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Delviks-Frankenberry KA, Desimmie BA, Pathak VK. Structural Insights into APOBEC3-Mediated Lentiviral Restriction. Viruses 2020; 12:E587. [PMID: 32471198 PMCID: PMC7354603 DOI: 10.3390/v12060587] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 05/22/2020] [Accepted: 05/24/2020] [Indexed: 01/18/2023] Open
Abstract
Mammals have developed clever adaptive and innate immune defense mechanisms to protect against invading bacterial and viral pathogens. Human innate immunity is continuously evolving to expand the repertoire of restriction factors and one such family of intrinsic restriction factors is the APOBEC3 (A3) family of cytidine deaminases. The coordinated expression of seven members of the A3 family of cytidine deaminases provides intrinsic immunity against numerous foreign infectious agents and protects the host from exogenous retroviruses and endogenous retroelements. Four members of the A3 proteins-A3G, A3F, A3H, and A3D-restrict HIV-1 in the absence of virion infectivity factor (Vif); their incorporation into progeny virions is a prerequisite for cytidine deaminase-dependent and -independent activities that inhibit viral replication in the host target cell. HIV-1 encodes Vif, an accessory protein that antagonizes A3 proteins by targeting them for polyubiquitination and subsequent proteasomal degradation in the virus producing cells. In this review, we summarize our current understanding of the role of human A3 proteins as barriers against HIV-1 infection, how Vif overcomes their antiviral activity, and highlight recent structural and functional insights into A3-mediated restriction of lentiviruses.
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Affiliation(s)
| | | | - Vinay K. Pathak
- Viral Mutation Section, HIV Dynamics and Replication Program, National Cancer Institute at Frederick, Frederick, MD 21702, USA; (K.A.D.-F.); (B.A.D.)
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3
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Azimi FC, Lee JE. Structural perspectives on HIV-1 Vif and APOBEC3 restriction factor interactions. Protein Sci 2020; 29:391-406. [PMID: 31518043 PMCID: PMC6954718 DOI: 10.1002/pro.3729] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 09/08/2019] [Accepted: 09/09/2019] [Indexed: 11/06/2022]
Abstract
Human immunodeficiency virus (HIV) is a retroviral pathogen that targets human immune cells such as CD4+ T cells, macrophages, and dendritic cells. The human apolipoprotein B mRNA- editing catalytic polypeptide 3 (APOBEC3 or A3) cytidine deaminases are a key class of intrinsic restriction factors that inhibit replication of HIV. When HIV-1 enters the cell, the immune system responds by inducing the activation of the A3 family proteins, which convert cytosines to uracils in single-stranded DNA replication intermediates, neutralizing the virus. HIV counteracts this intrinsic immune response by encoding a protein termed viral infectivity factor (Vif). Vif targets A3 to an E3 ubiquitin ligase complex for poly-ubiquitination and proteasomal degradation. Vif is unique in that it can recognize and counteract multiple A3 restriction factor substrates. Structural biology studies have provided significant insights into the overall architectures and functions of Vif and A3 proteins; however, a structure of the Vif-A3 complex has remained elusive. In this review, we summarize and reanalyze experimental data from recent structural, biochemical, and functional studies to provide key perspectives on the residues involved in Vif-A3 protein-protein interactions.
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Affiliation(s)
- Farshad C. Azimi
- Department of Laboratory Medicine and Pathobiology, Faculty of MedicineUniversity of TorontoTorontoOntarioCanada
| | - Jeffrey E. Lee
- Department of Laboratory Medicine and Pathobiology, Faculty of MedicineUniversity of TorontoTorontoOntarioCanada
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Ball KA, Chan LM, Stanley DJ, Tierney E, Thapa S, Ta HM, Burton L, Binning JM, Jacobson MP, Gross JD. Conformational Dynamics of the HIV-Vif Protein Complex. Biophys J 2019; 116:1432-1445. [PMID: 30961890 PMCID: PMC6486493 DOI: 10.1016/j.bpj.2019.03.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 02/27/2019] [Accepted: 03/02/2019] [Indexed: 12/29/2022] Open
Abstract
Human immunodeficiency virus-1 viral infectivity factor (Vif) is an intrinsically disordered protein responsible for the ubiquitination of the APOBEC3 (A3) antiviral proteins. Vif folds when it binds Cullin-RING E3 ligase 5 and the transcription cofactor CBF-β. A five-protein complex containing the substrate receptor (Vif, CBF-β, Elongin-B, Elongin-C (VCBC)) and Cullin5 (CUL5) has a published crystal structure, but dynamics of this VCBC-CUL5 complex have not been characterized. Here, we use molecular dynamics (MD) simulations and NMR to characterize the dynamics of the VCBC complex with and without CUL5 and an A3 protein bound. Our simulations show that the VCBC complex undergoes global dynamics involving twisting and clamshell opening of the complex, whereas VCBC-CUL5 maintains a more static conformation, similar to the crystal structure. This observation from MD is supported by methyl-transverse relaxation-optimized spectroscopy NMR data, which indicates that the VCBC complex without CUL5 is dynamic on the μs-ms timescale. Our NMR data also show that the VCBC complex is more conformationally restricted when bound to the antiviral APOBEC3F (one of the A3 proteins), consistent with our MD simulations. Vif contains a flexible linker region located at the hinge of the VCBC complex, which changes conformation in conjunction with the global dynamics of the complex. Like other substrate receptors, VCBC can exist alone or in complex with CUL5 and other proteins in cells. Accordingly, the VCBC complex could be a good target for therapeutics that would inhibit full assembly of the ubiquitination complex by stabilizing an alternate VCBC conformation.
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Affiliation(s)
- K Aurelia Ball
- Department of Chemistry, Skidmore College, Saratoga Springs, New York.
| | - Lieza M Chan
- Department of Chemistry, Skidmore College, Saratoga Springs, New York
| | - David J Stanley
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, California
| | - Elise Tierney
- Department of Chemistry, Skidmore College, Saratoga Springs, New York
| | - Sampriti Thapa
- Department of Chemistry, Skidmore College, Saratoga Springs, New York
| | - Hai M Ta
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, California
| | - Lily Burton
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, California
| | - Jennifer M Binning
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, California
| | - Matthew P Jacobson
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, California
| | - John D Gross
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, California.
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Jin J, Yan X, Liu Y, Lan W, Wang C, Xu B, Cao C. Recent Advances in the Structural Studies on Cytosine Deaminase APOBEC3 Family Members and Their Nucleic Acid Complexes. ACTA CHIMICA SINICA 2019. [DOI: 10.6023/a19080296] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Ai Y, Zhu D, Wang C, Su C, Ma J, Ma J, Wang X. Core-binding factor subunit beta is not required for non-primate lentiviral Vif-mediated APOBEC3 degradation. J Virol 2014; 88:12112-22. [PMID: 25122780 PMCID: PMC4178706 DOI: 10.1128/jvi.01924-14] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Accepted: 08/05/2014] [Indexed: 01/08/2023] Open
Abstract
Viral infectivity factor (Vif) is required for lentivirus fitness and pathogenicity, except in equine infectious anemia virus (EIAV). Vif enhances viral infectivity by a Cullin5-Elongin B/C E3 complex to inactivate the host restriction factor APOBEC3. Core-binding factor subunit beta (CBF-β) is a cell factor that was recently shown to be important for the primate lentiviral Vif function. Non-primate lentiviral Vif also degrades APOBEC3 through the proteasome pathway. However, it is unclear whether CBF-β is required for the non-primate lentiviral Vif function. In this study, we demonstrated that the Vifs of non-primate lentiviruses, including feline immunodeficiency virus (FIV), bovine immunodeficiency virus (BIV), caprine arthritis encephalitis virus (CAEV), and maedi-visna virus (MVV), do not interact with CBF-β. In addition, CBF-β did not promote the stability of FIV, BIV, CAEV, and MVV Vifs. Furthermore, CBF-β silencing or overexpression did not affect non-primate lentiviral Vif-mediated APOBEC3 degradation. Our results suggest that non-primate lentiviral Vif induces APOBEC3 degradation through a different mechanism than primate lentiviral Vif. Importance: The APOBEC3 protein family members are host restriction factors that block retrovirus replication. Vif, an accessory protein of lentivirus, degrades APOBEC3 to rescue viral infectivity by forming Cullin5-Elongin B/C-based E3 complex. CBF-β was proved to be a novel regulator of primate lentiviral Vif function. In this study, we found that CBF-β knockdown or overexpression did not affect FIV Vif's function, which induced polyubiquitination and degradation of APOBEC3 by recruiting the E3 complex in a manner similar to that of HIV-1 Vif. We also showed that other non-primate lentiviral Vifs did not require CBF-β to degrade APOBEC3. CBF-β did not interact with non-primate lentiviral Vifs or promote their stability. These results suggest that a different mechanism exists for the Vif-APOBEC interaction and that non-primates are not suitable animal models for exploring pharmacological interventions that disrupt Vif-CBF-β interaction.
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Affiliation(s)
- Youwei Ai
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China College of Wildlife Resources, Northeast Forestry University, Harbin, China
| | - Dantong Zhu
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China College of Wildlife Resources, Northeast Forestry University, Harbin, China
| | - Cuihui Wang
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Chao Su
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Jian Ma
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Jianzhang Ma
- College of Wildlife Resources, Northeast Forestry University, Harbin, China
| | - Xiaojun Wang
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
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da Costa KS, Leal E, dos Santos AM, Lima e Lima AH, Alves CN, Lameira J. Structural analysis of viral infectivity factor of HIV type 1 and its interaction with A3G, EloC and EloB. PLoS One 2014; 9:e89116. [PMID: 24586532 PMCID: PMC3935857 DOI: 10.1371/journal.pone.0089116] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2013] [Accepted: 01/15/2014] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND The virion infectivity factor (Vif) is an accessory protein, which is essential for HIV replication in host cells. Vif neutralizes the antiviral host protein APOBEC3 through recruitment of the E3 ubiquitin ligase complex. METHODOLOGY Fifty thousand Vif models were generated using the ab initio relax protocol of the Rosetta algorithm from sets of three- and nine-residue fragments using the fragment Monte Carlo insertion-simulated annealing strategy, which favors protein-like features, followed by an all-atom refinement. In the protocol, a constraints archive was used to define the spatial relationship between the side chains from Cys/His residues and zinc ions that formed the zinc-finger motif that is essential for Vif function. We also performed centroids analysis and structural analysis with respect to the formation of the zinc-finger, and the residue disposal in the protein binding domains. Additionally, molecular docking was used to explore details of Vif-A3G and Vif-EloBC interactions. Furthermore, molecular dynamics simulation was used to evaluate the stability of the complexes Vif-EloBC-A3G and Vif-EloC. PRINCIPAL FINDINGS The zinc in the HCCH domain significantly alters the folding of Vif and changes the structural dynamics of the HCCH region. Ab initio modeling indicated that the Vif zinc-finger possibly displays tetrahedral geometry as suggested by Mehle et al. (2006). Our model also showed that the residues L146 and L149 of the BC-box motif bind to EloC by hydrophobic interactions, and the residue P162 of the PPLP motif is important to EloB binding. CONCLUSIONS/SIGNIFICANCE The model presented here is the first complete three-dimensional structure of the Vif. The interaction of Vif with the A3G protein and the EloBC complex is in agreement with empirical data that is currently available in the literature and could therefore provide valuable structural information for advances in rational drug design.
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Affiliation(s)
- Kauê Santana da Costa
- Laboratório de Planejamento e Desenvolvimento de Fármacos, Instituto de Ciências Exatas e Naturais– ICEN e Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, Brazil
| | - Elcio Leal
- Faculdade de Biotecnologia, Universidade Federal do Pará, Belém, Brazil
| | - Alberto Monteiro dos Santos
- Laboratório de Planejamento e Desenvolvimento de Fármacos, Instituto de Ciências Exatas e Naturais– ICEN e Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, Brazil
| | - Anderson Henrique Lima e Lima
- Laboratório de Planejamento e Desenvolvimento de Fármacos, Instituto de Ciências Exatas e Naturais– ICEN e Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, Brazil
| | - Cláudio Nahum Alves
- Laboratório de Planejamento e Desenvolvimento de Fármacos, Instituto de Ciências Exatas e Naturais– ICEN e Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, Brazil
| | - Jerônimo Lameira
- Laboratório de Planejamento e Desenvolvimento de Fármacos, Instituto de Ciências Exatas e Naturais– ICEN e Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, Brazil
- Faculdade de Biotecnologia, Universidade Federal do Pará, Belém, Brazil
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