1
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Sluchanko NN, Shcheblyakov DV, Varfolomeeva LA, Favorskaya IA, Dolzhikova IV, Korobkova AI, Alekseeva IA, Esmagambetov IB, Derkaev AA, Prokofiev VV, Zorkov ID, Logunov DY, Gintsburg AL, Popov VO, Boyko KM. Structural Basis for Evasion of New SARS-CoV-2 Variants from the Potent Virus-Neutralizing Nanobody Targeting the S-Protein Receptor-Binding Domain. BIOCHEMISTRY. BIOKHIMIIA 2024; 89:1260-1272. [PMID: 39218023 DOI: 10.1134/s0006297924070083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2024] [Revised: 06/04/2024] [Accepted: 06/06/2024] [Indexed: 09/04/2024]
Abstract
COVID-19 has caused millions of deaths and many times more infections worldwide, emphasizing the unpreparedness of the global health system in the face of new infections and the key role for vaccines and therapeutics, including virus-neutralizing antibodies, in prevention and containment of the disease. Continuous evolution of the SARS-CoV-2 coronavirus has been causing its new variants to evade the action of the immune system, which highlighted the importance of detailed knowledge of the epitopes of already selected potent virus-neutralizing antibodies. A single-chain antibody ("nanobody") targeting the SARS-CoV-2 receptor-binding domain (RBD), clone P2C5, had exhibited robust virus-neutralizing activity against all SARS-CoV-2 variants and, being a major component of the anti-COVID-19 formulation "GamCoviMab", had successfully passed Phase I of clinical trials. However, after the emergence of the Delta and XBB variants, a decrease in the neutralizing activity of this nanobody was observed. Here we report on the successful crystal structure determination of the RBD:P2C5 complex at 3.1 Å, which revealed the intricate protein-protein interface, sterically occluding full ACE2 receptor binding by the P2C5-neutralized RBD. Moreover, the structure revealed the developed RBD:P2C5 interface centered around residues Leu452 and Phe490, thereby explaining the evasion of the Delta or Omicron XBB, but not Omicron B.1.1.529 variant, as a result of the single L452R or F490S mutations, respectively, from the action of P2C5. The structure obtained is expected to foster nanobody engineering in order to rescue neutralization activity and will facilitate epitope mapping for other neutralizing nanobodies by competition assays.
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Affiliation(s)
- Nikolai N Sluchanko
- Bach Institute of Biochemistry, Federal Research Centre "Fundamentals of Biotechnology", Russian Academy of Sciences, Moscow, 119071, Russia.
- National Research Center for Epidemiology and Microbiology named after Honorary Academician N. F. Gamaleya, Ministry of Health of the Russian Federation, Moscow, 123098, Russia
| | - Dmitry V Shcheblyakov
- National Research Center for Epidemiology and Microbiology named after Honorary Academician N. F. Gamaleya, Ministry of Health of the Russian Federation, Moscow, 123098, Russia.
| | - Larisa A Varfolomeeva
- Bach Institute of Biochemistry, Federal Research Centre "Fundamentals of Biotechnology", Russian Academy of Sciences, Moscow, 119071, Russia
| | - Irina A Favorskaya
- National Research Center for Epidemiology and Microbiology named after Honorary Academician N. F. Gamaleya, Ministry of Health of the Russian Federation, Moscow, 123098, Russia
| | - Inna V Dolzhikova
- National Research Center for Epidemiology and Microbiology named after Honorary Academician N. F. Gamaleya, Ministry of Health of the Russian Federation, Moscow, 123098, Russia
| | - Anastasia I Korobkova
- National Research Center for Epidemiology and Microbiology named after Honorary Academician N. F. Gamaleya, Ministry of Health of the Russian Federation, Moscow, 123098, Russia
| | - Irina A Alekseeva
- National Research Center for Epidemiology and Microbiology named after Honorary Academician N. F. Gamaleya, Ministry of Health of the Russian Federation, Moscow, 123098, Russia
| | - Ilias B Esmagambetov
- National Research Center for Epidemiology and Microbiology named after Honorary Academician N. F. Gamaleya, Ministry of Health of the Russian Federation, Moscow, 123098, Russia
| | - Artem A Derkaev
- National Research Center for Epidemiology and Microbiology named after Honorary Academician N. F. Gamaleya, Ministry of Health of the Russian Federation, Moscow, 123098, Russia
| | - Vladimir V Prokofiev
- National Research Center for Epidemiology and Microbiology named after Honorary Academician N. F. Gamaleya, Ministry of Health of the Russian Federation, Moscow, 123098, Russia
| | - Ilya D Zorkov
- National Research Center for Epidemiology and Microbiology named after Honorary Academician N. F. Gamaleya, Ministry of Health of the Russian Federation, Moscow, 123098, Russia
| | - Denis Y Logunov
- National Research Center for Epidemiology and Microbiology named after Honorary Academician N. F. Gamaleya, Ministry of Health of the Russian Federation, Moscow, 123098, Russia
| | - Alexander L Gintsburg
- National Research Center for Epidemiology and Microbiology named after Honorary Academician N. F. Gamaleya, Ministry of Health of the Russian Federation, Moscow, 123098, Russia
| | - Vladimir O Popov
- Bach Institute of Biochemistry, Federal Research Centre "Fundamentals of Biotechnology", Russian Academy of Sciences, Moscow, 119071, Russia
| | - Konstantin M Boyko
- Bach Institute of Biochemistry, Federal Research Centre "Fundamentals of Biotechnology", Russian Academy of Sciences, Moscow, 119071, Russia.
- National Research Center for Epidemiology and Microbiology named after Honorary Academician N. F. Gamaleya, Ministry of Health of the Russian Federation, Moscow, 123098, Russia
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2
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Condeminas M, Macias MJ. Overcoming challenges in structural biology with integrative approaches and nanobody-derived technologies. Curr Opin Struct Biol 2024; 84:102764. [PMID: 38215529 DOI: 10.1016/j.sbi.2023.102764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 11/24/2023] [Accepted: 12/11/2023] [Indexed: 01/14/2024]
Abstract
A full understanding of protein structure is key to unraveling how these systems work, how mutations affect their function, and discovering new hotspots for drug discovery. Research tackling this field began with the analysis of globular proteins. In recent years, as technology has improved, research efforts have broadened their focus to include the study of multidomain proteins and the analysis of conformational variability, flexibility, and dynamic systems. Here, we have selected five recent examples that integrate complementary structural methods to provide insight into the behavior of modular, flexible, and transient contacts. We also describe the structural application of domains derived from single-chain antibodies, which are instrumental in overcoming the size limitation of cryogenic electron microscopy (cryoEM) studies. As these methods are continuously developed, they will lead to the interrogation of more complex systems, revealing how large signaling and transcriptional machines are assembled in the context of health and disease.
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Affiliation(s)
- Miriam Condeminas
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Carrer de Baldiri Reixac 10, Barcelona 08028, Spain; Department of Medicine and Life Sciences, Universitat Pompeu Fabra (MELIS-UPF), Carrer del Doctor Aiguader 88, Barcelona 08003, Spain
| | - Maria J Macias
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Carrer de Baldiri Reixac 10, Barcelona 08028, Spain; Institució Catalana de Recerca i Estudis Avançats (ICREA), Passeig Lluís Companys 23, Barcelona 08010, Spain.
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3
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Davidge B, McDermott SM, Carnes J, Lewis I, Tracy M, Stuart KD. Multiple domains of the integral KREPA3 protein are critical for the structure and precise functions of RNA editing catalytic complexes in Trypanosoma brucei. RNA (NEW YORK, N.Y.) 2023; 29:1591-1609. [PMID: 37474258 PMCID: PMC10578492 DOI: 10.1261/rna.079691.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 06/30/2023] [Indexed: 07/22/2023]
Abstract
The gRNA directed U-insertion and deletion editing of mitochondrial mRNAs that is essential in different life-cycle stages for the protozoan parasite Trypanosoma brucei is performed by three similar multiprotein catalytic complexes (CCs) that contain the requisite enzymes. These CCs also contain a common set of eight proteins that have no apparent direct catalytic function, including six that have an OB-fold domain. We show here that one of these OB-fold proteins, KREPA3 (A3), has structural homology to other editing proteins, is essential for editing, and is multifunctional. We investigated A3 function by analyzing the effects of single amino acid loss of function mutations, most of which were identified by screening bloodstream form (BF) parasites for loss of growth following random mutagenesis. Mutations in the zinc fingers (ZFs), an intrinsically disordered region (IDR), and several within or near the carboxy-terminal OB-fold domain variably impacted CC structural integrity and editing. Some mutations resulted in almost complete loss of CCs and its proteins and editing, whereas others retained CCs but had aberrant editing. All but a mutation which is near the OB-fold affected growth and editing in BF but not procyclic form (PF) parasites. These data indicate that multiple positions within A3 have essential functions that contribute to the structural integrity of CCs, the precision of editing and the developmental differences in editing between BF and PF stages.
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Affiliation(s)
- Brittney Davidge
- Center for Global Infectious Disease Research (CGIDR), Seattle Children's Research Institute, Seattle, Washington 98109, USA
| | - Suzanne M McDermott
- Center for Global Infectious Disease Research (CGIDR), Seattle Children's Research Institute, Seattle, Washington 98109, USA
- Department of Pediatrics, University of Washington, Seattle, Washington 98195, USA
| | - Jason Carnes
- Center for Global Infectious Disease Research (CGIDR), Seattle Children's Research Institute, Seattle, Washington 98109, USA
| | - Isaac Lewis
- Center for Global Infectious Disease Research (CGIDR), Seattle Children's Research Institute, Seattle, Washington 98109, USA
| | - Maxwell Tracy
- Center for Global Infectious Disease Research (CGIDR), Seattle Children's Research Institute, Seattle, Washington 98109, USA
| | - Kenneth D Stuart
- Center for Global Infectious Disease Research (CGIDR), Seattle Children's Research Institute, Seattle, Washington 98109, USA
- Department of Pediatrics, University of Washington, Seattle, Washington 98195, USA
- Department of Global Health, University of Washington, Seattle, Washington 98195, USA
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4
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Davidge B, McDermott SM, Carnes J, Lewis I, Tracy M, Stuart KD. Multiple domains of the integral KREPA3 protein are critical for the structure and precise functions of RNA Editing Catalytic Complexes in Trypanosoma brucei. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.19.537538. [PMID: 37131796 PMCID: PMC10153193 DOI: 10.1101/2023.04.19.537538] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The gRNA directed U-insertion and deletion editing of mitochondrial mRNAs that is essential in different life cycle stages for the protozoan parasite Trypanosoma brucei is performed by three similar multi-protein catalytic complexes (CCs) that contain the requisite enzymes. These CCs also contain a common set of eight proteins that have no apparent direct catalytic function, including six that have an OB-fold domain. We show here that one of these OB-fold proteins, KREPA3 (A3), has structural homology to other editing proteins, is essential for editing and is multifunctional. We investigated A3 function by analyzing the effects of single amino acid loss of function mutations most of which were identified by screening bloodstream form (BF) parasites for loss of growth following random mutagenesis. Mutations in the ZFs, an intrinsically disordered region (IDR) and several within or near the C-terminal OB-fold domain variably impacted CC structural integrity and editing. Some mutations resulted in almost complete loss of CCs and its proteins and editing whereas others retained CCs but had aberrant editing. All but a mutation which is near the OB-fold affected growth and editing in BF but not procyclic form (PF) parasites. These data indicate that multiple positions within A3 have essential functions that contribute to the structural integrity of CCs, the precision of editing and the developmental differences in editing between BF and PF stages.
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Affiliation(s)
- Brittney Davidge
- Center for Global Infectious Disease Research (CGIDR), Seattle Children's Research Institute, Seattle, WA 98109
| | - Suzanne M McDermott
- Center for Global Infectious Disease Research (CGIDR), Seattle Children's Research Institute, Seattle, WA 98109
- Department of Pediatrics, University of Washington, Seattle, WA
| | - Jason Carnes
- Center for Global Infectious Disease Research (CGIDR), Seattle Children's Research Institute, Seattle, WA 98109
| | - Isaac Lewis
- Center for Global Infectious Disease Research (CGIDR), Seattle Children's Research Institute, Seattle, WA 98109
| | - Maxwell Tracy
- Center for Global Infectious Disease Research (CGIDR), Seattle Children's Research Institute, Seattle, WA 98109
| | - Kenneth D Stuart
- Center for Global Infectious Disease Research (CGIDR), Seattle Children's Research Institute, Seattle, WA 98109
- Department of Pediatrics, University of Washington, Seattle, WA
- Department of Global Health, University of Washington, Seattle, WA
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5
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Moliner-Morro A, McInerney GM, Hanke L. Nanobodies in the limelight: Multifunctional tools in the fight against viruses. J Gen Virol 2022; 103. [PMID: 35579613 DOI: 10.1099/jgv.0.001731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Antibodies are natural antivirals generated by the vertebrate immune system in response to viral infection or vaccination. Unsurprisingly, they are also key molecules in the virologist's molecular toolbox. With new developments in methods for protein engineering, protein functionalization and application, smaller antibody-derived fragments are moving in focus. Among these, camelid-derived nanobodies play a prominent role. Nanobodies can replace full-sized antibodies in most applications and enable new possible applications for which conventional antibodies are challenging to use. Here we review the versatile nature of nanobodies, discuss their promise as antiviral therapeutics, for diagnostics, and their suitability as research tools to uncover novel aspects of viral infection and disease.
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Affiliation(s)
- Ainhoa Moliner-Morro
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Gerald M McInerney
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
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6
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Insights into Comparative Modeling of V HH Domains. Int J Mol Sci 2021; 22:ijms22189771. [PMID: 34575931 PMCID: PMC8466624 DOI: 10.3390/ijms22189771] [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: 07/27/2021] [Revised: 08/27/2021] [Accepted: 09/04/2021] [Indexed: 12/13/2022] Open
Abstract
In the particular case of the Camelidae family, immunoglobulin proteins have evolved into a unique and more simplified architecture with only heavy chains. The variable domains of these chains, named VHHs, have a number of Complementary Determining Regions (CDRs) reduced by half, and can function as single domains making them good candidates for molecular tools. 3D structure prediction of these domains is a beneficial and advantageous step to advance their developability as molecular tools. Nonetheless, the conformations of CDRs loops in these domains remain difficult to predict due to their higher conformational diversity. In addition to CDRs loop diversity, our earlier study has established that Framework Regions (FRs) are also not entirely conformationally conserved which establishes a need for more rigorous analyses of these regions that could assist in template selection. In the current study, VHHs models using different template selection strategies for comparative modeling using Modeller have been extensively assessed. This study analyses the conformational changes in both CDRs and FRs using an original strategy of conformational discretization based on a structural alphabet. Conformational sampling in selected cases is precisely reported. Some interesting outcomes of the structural analyses of models also draw attention towards the distinct difficulty in 3D structure prediction of VHH domains.
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7
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Wang Y, Li R, Qiao S, Wang J, Liu H, Li Z, Ma H, Yang L, Ruan H, Weng M, Hiscox JA, Stewart JP, Nan Y, Zhang G, Zhou EM. Structural Characterization of Non-structural Protein 9 Complexed With Specific Nanobody Pinpoints Two Important Residues Involved in Porcine Reproductive and Respiratory Syndrome Virus Replication. Front Microbiol 2020; 11:581856. [PMID: 33281776 PMCID: PMC7688669 DOI: 10.3389/fmicb.2020.581856] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Accepted: 10/26/2020] [Indexed: 12/11/2022] Open
Abstract
Porcine reproductive and respiratory syndrome (PRRS), caused by PRRS virus (PRRSV), is a widespread viral disease that has led to huge economic losses for the global swine industry. Non-structural protein 9 (Nsp9) of PRRSV possesses essential RNA-dependent RNA polymerase (RdRp) activity for viral RNA replication. Our previous report showed that Nsp9-specific nanobody, Nb6, was able to inhibit PRRSV replication. In this study, recombinant Nsp9 and Nsp9-Nb6 complex were prepared then characterized using bio-layer interferometry (BLI) and dynamic light scattering (DLS) analyses that demonstrated high-affinity binding of Nb6 to Nsp9 to form a homogeneous complex. Small-angle X-ray scattering (SAXS) characterization analyses revealed that spatial interactions differed between Nsp9 and Nsp9-Nb6 complex molecular envelopes. Enzyme-linked immunosorbent assays (ELISAs) revealed key involvement of Nsp9 residues Ile588, Asp590, and Leu643 and Nb6 residues Tyr62, Trp105, and Pro107 in the Nsp9-Nb6 interaction. After reverse genetics-based techniques were employed to generate recombinant Nsp9 mutant viruses, virus replication efficiencies were assessed in MARC-145 cells. The results revealed impaired viral replication of recombinant viruses bearing I588A and L643A mutations as compared with replication of wild type virus, as evidenced by reduced negative-strand genomic RNA [(−) gRNA] synthesis and attenuated viral infection. Moreover, the isoleucine at position 588 of Nsp9 was conserved across PRRSV genotypes. In conclusion, structural analysis of the Nsp9-Nb6 complex revealed novel amino acid interactions involved in viral RNA replication that will be useful for guiding development of structure-based anti-PRRSV agents.
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Affiliation(s)
- Yan Wang
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Rui Li
- Key Laboratory of Animal Immunology of the Ministry of Agriculture, Henan Provincial Key Laboratory of Animal Immunology, Henan Academy of Agricultural Sciences, Zhengzhou, China
| | - Songlin Qiao
- Key Laboratory of Animal Immunology of the Ministry of Agriculture, Henan Provincial Key Laboratory of Animal Immunology, Henan Academy of Agricultural Sciences, Zhengzhou, China
| | - Jiaxi Wang
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Hongliang Liu
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Zhijun Li
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Hongfang Ma
- Key Laboratory of Animal Immunology of the Ministry of Agriculture, Henan Provincial Key Laboratory of Animal Immunology, Henan Academy of Agricultural Sciences, Zhengzhou, China
| | - Lei Yang
- Key Laboratory of Animal Immunology of the Ministry of Agriculture, Henan Provincial Key Laboratory of Animal Immunology, Henan Academy of Agricultural Sciences, Zhengzhou, China
| | - Haiyu Ruan
- Department of Infection Biology, Institute of Infection and Global Health, University of Liverpool, Liverpool, United Kingdom
| | - Maoyang Weng
- Key Laboratory of Animal Immunology of the Ministry of Agriculture, Henan Provincial Key Laboratory of Animal Immunology, Henan Academy of Agricultural Sciences, Zhengzhou, China
| | - Julian A Hiscox
- Department of Infection Biology, Institute of Infection and Global Health, University of Liverpool, Liverpool, United Kingdom
| | - James P Stewart
- Department of Infection Biology, Institute of Infection and Global Health, University of Liverpool, Liverpool, United Kingdom
| | - Yuchen Nan
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Gaiping Zhang
- Key Laboratory of Animal Immunology of the Ministry of Agriculture, Henan Provincial Key Laboratory of Animal Immunology, Henan Academy of Agricultural Sciences, Zhengzhou, China
| | - En-Min Zhou
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, China
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8
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Hu M, Kang G, Cheng X, Wang J, Li R, Bai Z, Yang D, Huang H. In vitro affinity maturation to improve the efficacy of a hypoxia-inducible factor 1α single-domain intrabody. Biochem Biophys Res Commun 2020; 529:936-942. [PMID: 32819602 DOI: 10.1016/j.bbrc.2020.06.097] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 06/17/2020] [Indexed: 12/14/2022]
Abstract
Affinity is an important property of therapeutic antibodies, so improving affinity is critical to the biological activity and clinical efficacy. An anti-HIF-1α nanobody, VHH212, was screened via a native ribosome display library with a 26.6 nM of KD value was used as the parent. In this paper, a Venn-intersection of multi-algorithms screening (VIMAS) strategy for computer-aided binding affinity prediction was designed. Homology modeling and protein docking methods were used to substitute the need for a crystal structure. Finally, a mutant with a 17.5-fold enhancement in binding affinity (1.52 nM) was obtained by using the VIMAS strategy. Furthermore, the biological activity of mutants was verified at the cellular level. Targeting HIF-1α can sensitize PDAC (pancreatic ductal adenocarcinoma) tumors to gemcitabine, which is a potential co-treatment method for pancreatic cancer patients. Our results showed that the cytotoxicity of gemcitabine on pancreatic cancer cell lines increased with the enhanced-affinity of an intrabody under combined treatment.
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MESH Headings
- Algorithms
- Antibody Affinity
- Antibody Specificity
- Antimetabolites, Antineoplastic/pharmacology
- Antineoplastic Agents, Immunological/chemistry
- Antineoplastic Agents, Immunological/metabolism
- Antineoplastic Agents, Immunological/pharmacology
- Binding Sites
- Cell Line, Tumor
- Cell Survival/drug effects
- Cell Survival/genetics
- Deoxycytidine/analogs & derivatives
- Deoxycytidine/pharmacology
- Humans
- Hypoxia-Inducible Factor 1, alpha Subunit/antagonists & inhibitors
- Hypoxia-Inducible Factor 1, alpha Subunit/genetics
- Hypoxia-Inducible Factor 1, alpha Subunit/immunology
- Molecular Docking Simulation
- Molecular Dynamics Simulation
- Mutation
- Pancreatic Ducts/immunology
- Pancreatic Ducts/pathology
- Protein Binding
- Protein Conformation, alpha-Helical
- Protein Conformation, beta-Strand
- Protein Interaction Domains and Motifs
- Single-Domain Antibodies/chemistry
- Single-Domain Antibodies/genetics
- Single-Domain Antibodies/pharmacology
- Structural Homology, Protein
- User-Computer Interface
- Gemcitabine
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Affiliation(s)
- Min Hu
- Department of Biochemical Engineering, School of Chemical Engineering & Technology, Tianjin University, Tianjin, 300350, China; Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, 300072, China
| | - Guangbo Kang
- Department of Biochemical Engineering, School of Chemical Engineering & Technology, Tianjin University, Tianjin, 300350, China; Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, 300072, China
| | - Xin Cheng
- Department of Biochemical Engineering, School of Chemical Engineering & Technology, Tianjin University, Tianjin, 300350, China; Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, 300072, China
| | - Jiewen Wang
- Department of Biochemical Engineering, School of Chemical Engineering & Technology, Tianjin University, Tianjin, 300350, China; Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, 300072, China
| | - Ruowei Li
- Department of Biochemical Engineering, School of Chemical Engineering & Technology, Tianjin University, Tianjin, 300350, China; Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, 300072, China
| | - Zixuan Bai
- Department of Biochemical Engineering, School of Chemical Engineering & Technology, Tianjin University, Tianjin, 300350, China; Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, 300072, China
| | - Dong Yang
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, 300072, China; School of Environmental Science & Engineering, Tianjin University, Tianjin, 300072, China.
| | - He Huang
- Department of Biochemical Engineering, School of Chemical Engineering & Technology, Tianjin University, Tianjin, 300350, China; Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, 300072, China.
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9
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Chiu ML, Goulet DR, Teplyakov A, Gilliland GL. Antibody Structure and Function: The Basis for Engineering Therapeutics. Antibodies (Basel) 2019; 8:antib8040055. [PMID: 31816964 PMCID: PMC6963682 DOI: 10.3390/antib8040055] [Citation(s) in RCA: 229] [Impact Index Per Article: 45.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 11/25/2019] [Accepted: 11/28/2019] [Indexed: 12/11/2022] Open
Abstract
Antibodies and antibody-derived macromolecules have established themselves as the mainstay in protein-based therapeutic molecules (biologics). Our knowledge of the structure–function relationships of antibodies provides a platform for protein engineering that has been exploited to generate a wide range of biologics for a host of therapeutic indications. In this review, our basic understanding of the antibody structure is described along with how that knowledge has leveraged the engineering of antibody and antibody-related therapeutics having the appropriate antigen affinity, effector function, and biophysical properties. The platforms examined include the development of antibodies, antibody fragments, bispecific antibody, and antibody fusion products, whose efficacy and manufacturability can be improved via humanization, affinity modulation, and stability enhancement. We also review the design and selection of binding arms, and avidity modulation. Different strategies of preparing bispecific and multispecific molecules for an array of therapeutic applications are included.
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Affiliation(s)
- Mark L. Chiu
- Drug Product Development Science, Janssen Research & Development, LLC, Malvern, PA 19355, USA
- Correspondence:
| | - Dennis R. Goulet
- Department of Medicinal Chemistry, University of Washington, P.O. Box 357610, Seattle, WA 98195-7610, USA;
| | - Alexey Teplyakov
- Biologics Research, Janssen Research & Development, LLC, Spring House, PA 19477, USA; (A.T.); (G.L.G.)
| | - Gary L. Gilliland
- Biologics Research, Janssen Research & Development, LLC, Spring House, PA 19477, USA; (A.T.); (G.L.G.)
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10
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Voigt C, Dobrychlop M, Kruse E, Czerwoniec A, Kasprzak JM, Bytner P, Campo CD, Leeder WM, Bujnicki JM, Göringer HU. The OB-fold proteins of the Trypanosoma brucei editosome execute RNA-chaperone activity. Nucleic Acids Res 2019; 46:10353-10367. [PMID: 30060205 PMCID: PMC6212840 DOI: 10.1093/nar/gky668] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Accepted: 07/13/2018] [Indexed: 02/01/2023] Open
Abstract
Sequence-deficient mitochondrial pre-mRNAs in African trypanosomes are substrates of a U-nucleotide-specific RNA editing reaction to generate translation-competent mRNAs. The reaction is catalyzed by a macromolecular protein complex termed the editosome. Editosomes execute RNA-chaperone activity to overcome the highly folded nature of pre-edited substrate mRNAs. The molecular basis for this activity is unknown. Here we test five of the OB-fold proteins of the Trypanosoma brucei editosome as candidates. We demonstrate that all proteins execute RNA-chaperone activity albeit to different degrees. We further show that the activities correlate to the surface areas of the proteins and we map the protein-induced RNA-structure changes using SHAPE-chemical probing. To provide a structural context for our findings we calculate a coarse-grained model of the editosome. The model has a shell-like structure: Structurally well-defined protein domains are separated from an outer shell of intrinsically disordered protein domains, which suggests a surface-driven mechanism for the chaperone activity.
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Affiliation(s)
- Christin Voigt
- Molecular Genetics, Darmstadt University of Technology, Darmstadt, Germany
| | - Mateusz Dobrychlop
- Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University, Poznan, Poland
| | - Elisabeth Kruse
- Molecular Genetics, Darmstadt University of Technology, Darmstadt, Germany
| | - Anna Czerwoniec
- Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University, Poznan, Poland
| | - Joanna M Kasprzak
- Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University, Poznan, Poland
| | - Patrycja Bytner
- Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University, Poznan, Poland
| | - Cristian Del Campo
- Molecular Genetics, Darmstadt University of Technology, Darmstadt, Germany
| | - W-Matthias Leeder
- Molecular Genetics, Darmstadt University of Technology, Darmstadt, Germany
| | - Janusz M Bujnicki
- Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University, Poznan, Poland.,Laboratory of Bioinformatics and Protein Engineering, International Institute of Molecular and Cell Biology, Warsaw, Poland
| | - H Ulrich Göringer
- Molecular Genetics, Darmstadt University of Technology, Darmstadt, Germany
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11
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Köhler M, Neff C, Perez C, Brunner C, Pardon E, Steyaert J, Schneider G, Locher KP, Zenobi R. Binding Specificities of Nanobody•Membrane Protein Complexes Obtained from Chemical Cross-Linking and High-Mass MALDI Mass Spectrometry. Anal Chem 2018; 90:5306-5313. [PMID: 29562137 DOI: 10.1021/acs.analchem.8b00236] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The application of nanobodies as binding partners for structure stabilization in protein X-ray crystallography is taking an increasingly important role in structural biology. However, the addition of nanobodies to the crystallization matrices might complicate the optimization of the crystallization process, which is why analytical techniques to screen and characterize suitable nanobodies are useful. Here, we show how chemical cross-linking combined with high-mass matrix-assisted laser/desorption ionization mass spectrometry can be employed as a fast screening technique to determine binding specificities of intact nanobody•membrane protein complexes. Titration series were performed to rank the binding affinity of the interacting nanobodies. To validate the mass spectrometry data, microscale thermophoresis was used, which showed binding affinities of the stronger binding nanobodies, in the low μM range. In addition, mass spectrometry provides access to the stoichiometry of the complexes formed, which enables the definition of conditions under which homogeneous complex states are present in solution. Conformational changes of the membrane protein were investigated and competitive binding experiments were used to delimit the interaction sites of the nanobodies, which is in agreement with crystal structures obtained. The results show the diversity of specifically binding nanobodies in terms of binding affinity, stoichiometry, and binding site, which illustrates the need for an analytical screening approach.
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Affiliation(s)
- Martin Köhler
- Department of Chemistry and Applied Biosciences , ETH Zürich , Vladimir-Prelog-Weg 3 , 8093 Zurich , Switzerland
| | - Christoph Neff
- Department of Chemistry and Applied Biosciences , ETH Zürich , Vladimir-Prelog-Weg 3 , 8093 Zurich , Switzerland
| | - Camilo Perez
- Institute of Molecular Biology and Biophysics , ETH Zürich , Otto-Stern-Weg 5 , 8093 Zurich , Switzerland
| | - Cyrill Brunner
- Department of Chemistry and Applied Biosciences , ETH Zürich , Vladimir-Prelog-Weg 3 , 8093 Zurich , Switzerland
| | | | | | - Gisbert Schneider
- Department of Chemistry and Applied Biosciences , ETH Zürich , Vladimir-Prelog-Weg 3 , 8093 Zurich , Switzerland
| | - Kaspar P Locher
- Institute of Molecular Biology and Biophysics , ETH Zürich , Otto-Stern-Weg 5 , 8093 Zurich , Switzerland
| | - Renato Zenobi
- Department of Chemistry and Applied Biosciences , ETH Zürich , Vladimir-Prelog-Weg 3 , 8093 Zurich , Switzerland
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12
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Desmyter A, Spinelli S, Boutton C, Saunders M, Blachetot C, de Haard H, Denecker G, Van Roy M, Cambillau C, Rommelaere H. Neutralization of Human Interleukin 23 by Multivalent Nanobodies Explained by the Structure of Cytokine-Nanobody Complex. Front Immunol 2017; 8:884. [PMID: 28871249 PMCID: PMC5566574 DOI: 10.3389/fimmu.2017.00884] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2017] [Accepted: 07/11/2017] [Indexed: 11/26/2022] Open
Abstract
The heterodimeric cytokine interleukin (IL) 23 comprises the IL12-shared p40 subunit and an IL23-specific subunit, p19. Together with IL12 and IL27, IL23 sits at the apex of the regulatory mechanisms shaping adaptive immune responses. IL23, together with IL17, plays an important role in the development of chronic inflammation and autoimmune inflammatory diseases. In this context, we generated monovalent antihuman IL23 variable heavy chain domain of llama heavy chain antibody (VHH) domains (Nanobodies®) with low nanomolar affinity for human interleukin (hIL) 23. The crystal structure of a quaternary complex assembling hIL23 and several nanobodies against p19 and p40 subunits allowed identification of distinct epitopes and enabled rational design of a multivalent IL23-specific blocking nanobody. Taking advantage of the ease of nanobody formatting, multivalent IL23 nanobodies were assembled with properly designed linkers flanking an antihuman serum albumin nanobody, with improved hIL23 neutralization capacity in vitro and in vivo, as compared to the monovalent nanobodies. These constructs with long exposure time are excellent candidates for further developments targeting Crohn’s disease, rheumatoid arthritis, and psoriasis.
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Affiliation(s)
- Aline Desmyter
- Architecture et Fonction des Macromolécules Biologiques (AFMB), UMR 7257, Centre National de la Recherche Scientifique (CNRS), Marseille, France.,Architecture et Fonction des Macromolécules Biologiques (AFMB), UMR 7257, Aix-Marseille Université, Marseille, France
| | - Silvia Spinelli
- Architecture et Fonction des Macromolécules Biologiques (AFMB), UMR 7257, Centre National de la Recherche Scientifique (CNRS), Marseille, France.,Architecture et Fonction des Macromolécules Biologiques (AFMB), UMR 7257, Aix-Marseille Université, Marseille, France
| | | | | | | | | | | | | | - Christian Cambillau
- Architecture et Fonction des Macromolécules Biologiques (AFMB), UMR 7257, Centre National de la Recherche Scientifique (CNRS), Marseille, France.,Architecture et Fonction des Macromolécules Biologiques (AFMB), UMR 7257, Aix-Marseille Université, Marseille, France
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13
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Abstract
Uridine insertion and deletion RNA editing generates functional mitochondrial mRNAs in Trypanosoma brucei Editing is catalyzed by three distinct ∼20S editosomes that have a common set of 12 proteins, but are typified by mutually exclusive RNase III endonucleases with distinct cleavage specificities and unique partner proteins. Previous studies identified a network of protein-protein interactions among a subset of common editosome proteins, but interactions among the endonucleases and their partner proteins, and their interactions with common subunits were not identified. Here, chemical cross-linking and mass spectrometry, comparative structural modeling, and genetic and biochemical analyses were used to define the molecular architecture and subunit organization of purified editosomes. We identified intra- and interprotein cross-links for all editosome subunits that are fully consistent with editosome protein structures and previously identified interactions, which we validated by genetic and biochemical studies. The results were used to create a highly detailed map of editosome protein domain proximities, leading to identification of molecular interactions between subunits, insights into the functions of noncatalytic editosome proteins, and a global understanding of editosome architecture.
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14
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Dmitriev OY, Lutsenko S, Muyldermans S. Nanobodies as Probes for Protein Dynamics in Vitro and in Cells. J Biol Chem 2015; 291:3767-75. [PMID: 26677230 DOI: 10.1074/jbc.r115.679811] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Nanobodies are the recombinant antigen-recognizing domains of the minimalistic heavy chain-only antibodies produced by camels and llamas. Nanobodies can be easily generated, effectively optimized, and variously derivatized with standard molecular biology protocols. These properties have triggered the recent explosion in the nanobody use in basic and clinical research. This review focuses on the emerging use of nanobodies for understanding and monitoring protein dynamics on the scales ranging from isolated protein domains to live cells, from nanoseconds to hours. The small size and high solubility make nanobodies uniquely suited for studying protein dynamics by NMR. The ability to produce conformation-sensitive nanobodies in cells enables studies that link structural dynamics of a target protein to its cellular behavior. The link between in vitro and in-cell dynamics, afforded by nanobodies, brings the analysis of such important events as receptor signaling, membrane protein trafficking, and protein interactions to the next level of resolution.
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Affiliation(s)
- Oleg Y Dmitriev
- From the Department of Biochemistry, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E5, Canada,
| | - Svetlana Lutsenko
- the Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, and
| | - Serge Muyldermans
- the Unit of Cellular and Molecular Immunology, Vrije Universiteit Brussel, 1050, Brussels, Belgium
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15
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Czerwoniec A, Kasprzak JM, Bytner P, Dobrychłop M, Bujnicki JM. Structure and intrinsic disorder of the proteins of the Trypanosoma brucei editosome. FEBS Lett 2015; 589:2603-10. [PMID: 26226426 DOI: 10.1016/j.febslet.2015.07.026] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Revised: 07/21/2015] [Accepted: 07/22/2015] [Indexed: 01/02/2023]
Abstract
Mitochondrial pre-mRNAs in trypanosomatids undergo RNA editing to be converted into translatable mRNAs. The reaction is characterized by the insertion and deletion of uridine residues and is catalyzed by a macromolecular protein complex called the editosome. Despite intensive research, structural information for the majority of editosome proteins is still missing and no high resolution structure for the editosome exists. Here we present a comprehensive structural bioinformatics analysis of all proteins of the Trypanosoma brucei editosome. We specifically focus on the interplay between intrinsic order and disorder. According to computational predictions, editosome proteins involved in the basal reaction steps of the processing cycle are mostly ordered. By contrast, thirty percent of the amino acid content of the editosome is intrinsically disordered, which includes most prominently proteins with OB-fold domains. Based on the data we suggest a functional model, in which the structurally disordered domains of the complex are correlated with the RNA binding and RNA unfolding activity of the T. brucei editosome.
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Affiliation(s)
- Anna Czerwoniec
- Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University, Umultowska 89, PL-61-614 Poznan, Poland.
| | - Joanna M Kasprzak
- Laboratory of Bioinformatics and Protein Engineering, International Institute of Molecular and Cell Biology, Trojdena 4, PL-02-109 Warsaw, Poland; Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University, Umultowska 89, PL-61-614 Poznan, Poland
| | - Patrycja Bytner
- Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University, Umultowska 89, PL-61-614 Poznan, Poland
| | - Mateusz Dobrychłop
- Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University, Umultowska 89, PL-61-614 Poznan, Poland
| | - Janusz M Bujnicki
- Laboratory of Bioinformatics and Protein Engineering, International Institute of Molecular and Cell Biology, Trojdena 4, PL-02-109 Warsaw, Poland; Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University, Umultowska 89, PL-61-614 Poznan, Poland.
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16
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Simpson L, Douglass SM, Lake JA, Pellegrini M, Li F. Comparison of the Mitochondrial Genomes and Steady State Transcriptomes of Two Strains of the Trypanosomatid Parasite, Leishmania tarentolae. PLoS Negl Trop Dis 2015. [PMID: 26204118 PMCID: PMC4512693 DOI: 10.1371/journal.pntd.0003841] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
U-insertion/deletion RNA editing is a post-transcriptional mitochondrial RNA modification phenomenon required for viability of trypanosomatid parasites. Small guide RNAs encoded mainly by the thousands of catenated minicircles contain the information for this editing. We analyzed by NGS technology the mitochondrial genomes and transcriptomes of two strains, the old lab UC strain and the recently isolated LEM125 strain. PacBio sequencing provided complete minicircle sequences which avoided the assembly problem of short reads caused by the conserved regions. Minicircles were identified by a characteristic size, the presence of three short conserved sequences, a region of inherently bent DNA and the presence of single gRNA genes at a fairly defined location. The LEM125 strain contained over 114 minicircles encoding different gRNAs and the UC strain only ~24 minicircles. Some LEM125 minicircles contained no identifiable gRNAs. Approximate copy numbers of the different minicircle classes in the network were determined by the number of PacBio CCS reads that assembled to each class. Mitochondrial RNA libraries from both strains were mapped against the minicircle and maxicircle sequences. Small RNA reads mapped to the putative gRNA genes but also to multiple regions outside the genes on both strands and large RNA reads mapped in many cases over almost the entire minicircle on both strands. These data suggest that minicircle transcription is complete and bidirectional, with 3’ processing yielding the mature gRNAs. Steady state RNAs in varying abundances are derived from all maxicircle genes, including portions of the repetitive divergent region. The relative extents of editing in both strains correlated with the presence of a cascade of cognate gRNAs. These data should provide the foundation for a deeper understanding of this dynamic genetic system as well as the evolutionary variation of editing in different strains. U-insertion/deletion RNA editing is a unique post-transcriptional mRNA modification process that occurs in trypanosomatid parasites and is required for viability. The participation of guide RNAs which are transcribed from the thousands of catenated minicircles in determining the precise sites and number of U’s inserted and deleted to create translatable mRNAs is novel and significant in terms of the recently realized importance of small RNAs in biology. This study contributes the necessary bioinformatics foundation for a deeper understanding of this important genetic system in molecular detail using a model trypanosomatid, Leishmania tarentolae. We used Next Generation Sequencing methods to determine the complete maxicircle and minicircle genomes and to map maxicircle pre-edited and edited transcripts and minicircle transcripts. The transcription of minicircle-encoded guide RNAs was confirmed and novel information about minicircle gene expression was obtained. The biological context involved a comparison of two strains of the parasites, one recently isolated and having an intact mitochondrial genetic system and the other an old lab strain that has developed a partially defective mitochondrial genome. The data are important for an understanding of the mitochondrial genomic complexity and expression of this dynamic genetic system.
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Affiliation(s)
- Larry Simpson
- Department of Microbiology, Immunology and Molecular Genetics, Geffen School of Medicine at UCLA, University of California, Los Angeles, Los Angeles, California, United States of America
- * E-mail:
| | - Stephen M. Douglass
- Bioinformatics Interdepartmental Program, University of California, Los Angeles, Los Angeles, California, United States of America
- Department of Molecular, Cellular and Developmental Biology, University of California, Los Angeles, Los Angeles, California, United States of America
| | - James A. Lake
- Department of Molecular, Cellular and Developmental Biology, University of California, Los Angeles, Los Angeles, California, United States of America
| | - Matteo Pellegrini
- Department of Molecular, Cellular and Developmental Biology, University of California, Los Angeles, Los Angeles, California, United States of America
| | - Feng Li
- Dental Research Institute, School of Dentistry, University of California, Los Angeles, Los Angeles, California, United States of America
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17
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Nguyen VS, Spinelli S, Desmyter A, Le TTH, Kellenberger C, Cascales E, Cambillau C, Roussel A. Production, crystallization and X-ray diffraction analysis of a complex between a fragment of the TssM T6SS protein and a camelid nanobody. Acta Crystallogr F Struct Biol Commun 2015; 71:266-71. [PMID: 25760699 PMCID: PMC4356300 DOI: 10.1107/s2053230x15000709] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2014] [Accepted: 01/13/2015] [Indexed: 11/10/2022] Open
Abstract
The type VI secretion system (T6SS) is a machine evolved by Gram-negative bacteria to deliver toxin effectors into target bacterial or eukaryotic cells. The T6SS is functionally and structurally similar to the contractile tail of the Myoviridae family of bacteriophages and can be viewed as a syringe anchored to the bacterial membrane by a transenvelope complex. The membrane complex is composed of three proteins: the TssM and TssL inner membrane components and the TssJ outer membrane lipoprotein. The TssM protein is central as it interacts with both TssL and TssJ, therefore linking the membranes. Using controlled trypsinolysis, a 32.4 kDa C-terminal fragment of enteroaggregative Escherichia coli TssM (TssM32Ct) was purified. A nanobody obtained from llama immunization, nb25, exhibited subnanomolar affinity for TssM32Ct. Crystals of the TssM32Ct-nb25 complex were obtained and diffracted to 1.9 Å resolution. The crystals belonged to space group P64, with unit-cell parameters a = b = 95.23, c = 172.95 Å. Molecular replacement with a model nanobody indicated the presence of a dimer of TssM32Ct-nb25 in the asymmetric unit.
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Affiliation(s)
- Van Son Nguyen
- Architecture et Fonction des Macromolécules Biologiques, CNRS, Campus de Luminy, Case 932, 13288 Marseille, France
- Architecture et Fonction des Macromolécules Biologiques, Aix-Marseille Université, Campus de Luminy, Case 932, 13288 Marseille, France
| | - Silvia Spinelli
- Architecture et Fonction des Macromolécules Biologiques, CNRS, Campus de Luminy, Case 932, 13288 Marseille, France
- Architecture et Fonction des Macromolécules Biologiques, Aix-Marseille Université, Campus de Luminy, Case 932, 13288 Marseille, France
| | - Aline Desmyter
- Architecture et Fonction des Macromolécules Biologiques, CNRS, Campus de Luminy, Case 932, 13288 Marseille, France
- Architecture et Fonction des Macromolécules Biologiques, Aix-Marseille Université, Campus de Luminy, Case 932, 13288 Marseille, France
| | - Thi Thu Hang Le
- Architecture et Fonction des Macromolécules Biologiques, CNRS, Campus de Luminy, Case 932, 13288 Marseille, France
- Architecture et Fonction des Macromolécules Biologiques, Aix-Marseille Université, Campus de Luminy, Case 932, 13288 Marseille, France
| | - Christine Kellenberger
- Architecture et Fonction des Macromolécules Biologiques, CNRS, Campus de Luminy, Case 932, 13288 Marseille, France
- Architecture et Fonction des Macromolécules Biologiques, Aix-Marseille Université, Campus de Luminy, Case 932, 13288 Marseille, France
| | - Eric Cascales
- Laboratoire d’Ingénierie des Systèmes Macromoléculaires, Institut de Microbiologie de la Méditerranée, CNRS and Aix-Marseille Université, 31 Chemin Joseph Aiguier, 13402 Marseille, France
| | - Christian Cambillau
- Architecture et Fonction des Macromolécules Biologiques, CNRS, Campus de Luminy, Case 932, 13288 Marseille, France
- Architecture et Fonction des Macromolécules Biologiques, Aix-Marseille Université, Campus de Luminy, Case 932, 13288 Marseille, France
| | - Alain Roussel
- Architecture et Fonction des Macromolécules Biologiques, CNRS, Campus de Luminy, Case 932, 13288 Marseille, France
- Architecture et Fonction des Macromolécules Biologiques, Aix-Marseille Université, Campus de Luminy, Case 932, 13288 Marseille, France
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18
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Llama immunization with full-length VAR2CSA generates cross-reactive and inhibitory single-domain antibodies against the DBL1X domain. Sci Rep 2014; 4:7373. [PMID: 25487735 PMCID: PMC5376981 DOI: 10.1038/srep07373] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Accepted: 11/10/2014] [Indexed: 12/11/2022] Open
Abstract
VAR2CSA stands today as the leading vaccine candidate aiming to protect future pregnant women living in malaria endemic areas against the severe clinical outcomes of pregnancy associated malaria (PAM). The rational design of an efficient VAR2CSA-based vaccine relies on a profound understanding of the molecular interactions associated with P. falciparum infected erythrocyte sequestration in the placenta. Following immunization of a llama with the full-length VAR2CSA recombinant protein, we have expressed and characterized a panel of 19 nanobodies able to recognize the recombinant VAR2CSA as well as the surface of erythrocytes infected with parasites originating from different parts of the world. Domain mapping revealed that a large majority of nanobodies targeted DBL1X whereas a few of them were directed towards DBL4ε, DBL5ε and DBL6ε. One nanobody targeting the DBL1X was able to recognize the native VAR2CSA protein of the three parasite lines tested. Furthermore, four nanobodies targeting DBL1X reproducibly inhibited CSA adhesion of erythrocytes infected with the homologous NF54-CSA parasite strain, providing evidences that DBL1X domain is part or close to the CSA binding site. These nanobodies could serve as useful tools to identify conserved epitopes shared between different variants and to characterize the interactions between VAR2CSA and CSA.
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19
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Huh I, Gene R, Kumaran J, MacKenzie CR, Brooks CL. In situ proteolysis, crystallization and preliminary X-ray diffraction analysis of a VHH that binds listeria internalin B. Acta Crystallogr F Struct Biol Commun 2014; 70:1532-5. [PMID: 25372824 PMCID: PMC4231859 DOI: 10.1107/s2053230x1402010x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Accepted: 09/05/2014] [Indexed: 01/25/2023] Open
Abstract
The variable region of camelid heavy-chain antibodies produces the smallest known antibody fragment with antigen-binding capability (a VHH). The VHH R303 binds internalin B (InlB), a virulence factor expressed by the pathogen Listeria monocytogenes. InlB is critical for initiation of Listeria infection, as it binds a receptor (c-Met) on epithelial cells, triggering the entry of bacteria into host cells. InlB is surface-exposed and is required for virulence, hence a VHH targeting InlB has potential applications for pathogen detection or therapeutic intervention. Here, the expression, purification, crystallization and X-ray diffraction of R303 are reported. Crystals of R303 were obtained following in situ proteolysis with trypsin. Gel filtration and SDS-PAGE revealed that trypsin removed the C-terminal tag region of R303, facilitating crystal formation. Crystals of R303 diffracted to 1.3 Å resolution and belonged to the monoclinic space group P2₁, with unit-cell parameters a=46.4, b=31.2, c=74.8 Å, β=93.8°. The crystals exhibited a Matthews coefficient of 1.95 Å3 Da(-1) with two molecules in the asymmetric unit.
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Affiliation(s)
- Ian Huh
- Department of Chemistry, California State University Fresno, 2555 E. San Ramon Avenue, Fresno, CA 93740, USA
| | - Robert Gene
- Human Health Therapeutics, National Research Council of Canada, 100 Sussex Drive, Ottawa, ON K1A 0R6, Canada
- School of Environment Sciences, University of Guelph, 50 Stone Road East, Guelph, ON N1G 2W1, Canada
| | - Jyothi Kumaran
- Human Health Therapeutics, National Research Council of Canada, 100 Sussex Drive, Ottawa, ON K1A 0R6, Canada
- School of Environment Sciences, University of Guelph, 50 Stone Road East, Guelph, ON N1G 2W1, Canada
| | - C. Roger MacKenzie
- Human Health Therapeutics, National Research Council of Canada, 100 Sussex Drive, Ottawa, ON K1A 0R6, Canada
- School of Environment Sciences, University of Guelph, 50 Stone Road East, Guelph, ON N1G 2W1, Canada
| | - Cory L. Brooks
- Department of Chemistry, California State University Fresno, 2555 E. San Ramon Avenue, Fresno, CA 93740, USA
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20
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George J, Compton JR, Leary DH, Olson MA, Legler PM. Structural and mutational analysis of a monomeric and dimeric form of a single domain antibody with implications for protein misfolding. Proteins 2014; 82:3101-16. [PMID: 25136772 DOI: 10.1002/prot.24671] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Revised: 08/01/2014] [Accepted: 08/11/2014] [Indexed: 11/10/2022]
Abstract
Camelid single domain antibodies (sdAb) are known for their thermal stability and reversible refolding. We have characterized an unusually stable sdAb recognizing Staphylococcal enterotoxin B with one of the highest reported melting temperatures (T(m) = 85°C). Unexpectedly, ∼10-20% of the protein formed a dimer in solution. Three other cases where <20% of the sdAb dimerized have been reported; however, this is the first report of both the monomeric and dimeric X-ray crystal structures. Concentration of the monomer did not lead to the formation of new dimer suggesting a stable conformationally distinct species in a fraction of the cytoplasmically expressed protein. Comparison of periplasmic and cytoplasmic expression showed that the dimer was associated with cytoplasmic expression. The disulfide bond was partially reduced in the WT protein purified from the cytoplasm and the protein irreversibly unfolded. Periplasmic expression produced monomeric protein with a fully formed disulfide bond and mostly reversible refolding. Crystallization of a disulfide-bond free variant, C22A/C99V, purified from the periplasm yielded a structure of a monomeric form, while crystallization of C22A/C99V from the cytoplasm produced an asymmetric dimer. In the dimer, a significant conformational asymmetry was found in the loop residues of the edge β-strands (S50-Y60) containing the highly variable complementarity determining region, CDR2. Two dimeric assemblies were predicted from the crystal packing. Mutation of a residue at one of the interfaces, Y98A, disrupted the dimer in solution. The pleomorphic homodimer may yield insight into the stability of misfolded states and the importance of the conserved disulfide bond in preventing their formation.
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Affiliation(s)
- Jade George
- Bowie State University, Bowie, 14000 Jericho Park Road, Maryland, 20715-9465
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21
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Abstract
GAK (cyclin G-associated kinase) is a key regulator of clathrin-coated vesicle trafficking and plays a central role during development. Additionally, due to the unusually high plasticity of its catalytic domain, it is a frequent ‘off-target’ of clinical kinase inhibitors associated with respiratory side effects of these drugs. In the present paper, we determined the crystal structure of the GAK catalytic domain alone and in complex with specific single-chain antibodies (nanobodies). GAK is constitutively active and weakly associates in solution. The GAK apo structure revealed a dimeric inactive state of the catalytic domain mediated by an unusual activation segment interaction. Co-crystallization with the nanobody NbGAK_4 trapped GAK in a dimeric arrangement similar to the one observed in the apo structure, whereas NbGAK_1 captured the activation segment of monomeric GAK in a well-ordered conformation, representing features of the active kinase. The presented structural and biochemical data provide insight into the domain plasticity of GAK and demonstrate the utility of nanobodies to gain insight into conformational changes of dynamic molecules. In addition, we present structural data on the binding mode of ATP mimetic inhibitors and enzyme kinetic data, which will support rational inhibitor design of inhibitors to reduce the off-target effect on GAK. Cyclin G-associated kinase (GAK) is a regulator of clathrin-coated vesicle trafficking. The determined crystal structures of GAK in complex with specific single chain antibodies (nanobodies) revealed the domain plasticity of this kinase and unusual activation segment architecture.
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22
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Pardon E, Laeremans T, Triest S, Rasmussen SGF, Wohlkönig A, Ruf A, Muyldermans S, Hol WGJ, Kobilka BK, Steyaert J. A general protocol for the generation of Nanobodies for structural biology. Nat Protoc 2014; 9:674-93. [PMID: 24577359 PMCID: PMC4297639 DOI: 10.1038/nprot.2014.039] [Citation(s) in RCA: 498] [Impact Index Per Article: 49.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
There is growing interest in using antibodies as auxiliary tools to crystallize proteins. Here we describe a general protocol for the generation of Nanobodies to be used as crystallization chaperones for the structural investigation of diverse conformational states of flexible (membrane) proteins and complexes thereof. Our technology has a competitive advantage over other recombinant crystallization chaperones in that we fully exploit the natural humoral response against native antigens. Accordingly, we provide detailed protocols for the immunization with native proteins and for the selection by phage display of in vivo-matured Nanobodies that bind conformational epitopes of functional proteins. Three representative examples illustrate that the outlined procedures are robust, making it possible to solve by Nanobody-assisted X-ray crystallography in a time span of 6-12 months.
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Affiliation(s)
- Els Pardon
- 1] Structural Biology Brussels, Vrije Universiteit Brussel (VUB), Brussels, Belgium. [2] Structural Biology Research Center, Vlaams Instituut voor Biotechnologie (VIB), Brussels, Belgium
| | - Toon Laeremans
- 1] Structural Biology Brussels, Vrije Universiteit Brussel (VUB), Brussels, Belgium. [2] Structural Biology Research Center, Vlaams Instituut voor Biotechnologie (VIB), Brussels, Belgium
| | - Sarah Triest
- 1] Structural Biology Brussels, Vrije Universiteit Brussel (VUB), Brussels, Belgium. [2] Structural Biology Research Center, Vlaams Instituut voor Biotechnologie (VIB), Brussels, Belgium
| | - Søren G F Rasmussen
- Department of Neuroscience and Pharmacology, The Panum Institute, University of Copenhagen, Copenhagen, Denmark
| | - Alexandre Wohlkönig
- 1] Structural Biology Brussels, Vrije Universiteit Brussel (VUB), Brussels, Belgium. [2] Structural Biology Research Center, Vlaams Instituut voor Biotechnologie (VIB), Brussels, Belgium
| | - Armin Ruf
- Pharma Research and Early Development (pRED), Small Molecule Research, Discovery Technologies, F. Hoffmann-La Roche, Basel, Switzerland
| | - Serge Muyldermans
- 1] Structural Biology Research Center, Vlaams Instituut voor Biotechnologie (VIB), Brussels, Belgium. [2] Cellular and Molecular Immunology, VUB, Brussels, Belgium
| | - Wim G J Hol
- Department of Biochemistry, Biomolecular Structure Center, School of Medicine, University of Washington, Seattle, Washington, USA
| | - Brian K Kobilka
- Department of Molecular and Cellular Physiology, School of Medicine, Stanford University, Stanford, California, USA
| | - Jan Steyaert
- 1] Structural Biology Brussels, Vrije Universiteit Brussel (VUB), Brussels, Belgium. [2] Structural Biology Research Center, Vlaams Instituut voor Biotechnologie (VIB), Brussels, Belgium
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23
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Nanobody mediated crystallization of an archeal mechanosensitive channel. PLoS One 2013; 8:e77984. [PMID: 24205053 PMCID: PMC3804602 DOI: 10.1371/journal.pone.0077984] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Accepted: 09/16/2013] [Indexed: 11/19/2022] Open
Abstract
Mechanosensitive channels (MS) are integral membrane proteins and allow bacteria to survive sudden changes in external osmolarity due to transient opening of their pores. The efflux of cytoplasmic osmolytes reduces the membrane tension and prevents membrane rupture. Therefore these channels serve as emergency valves when experiencing significant environmental stress. The preparation of high quality crystals of integral membrane proteins is a major bottleneck for structure determination by X-ray crystallography. Crystallization chaperones based on various protein scaffolds have emerged as promising tool to increase the crystallization probability of a selected target protein. So far archeal mechanosensitive channels of small conductance have resisted crystallization in our hands. To structurally analyse these channels, we selected nanobodies against an archeal MS channel after immunization of a llama with recombinant expressed, detergent solubilized and purified protein. Here we present the characterization of 23 different binders regarding their interaction with the channel protein using analytical gel filtration, western blotting and surface plasmon resonance. Selected nanobodies bound the target with affinities in the pico- to nanomolar range and some binders had a profound effect on the crystallization of the MS channel. Together with previous data we show that nanobodies are a versatile and valuable tool in structural biology by widening the crystallization space for highly challenging proteins, protein complexes and integral membrane proteins.
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24
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Structures of P-glycoprotein reveal its conformational flexibility and an epitope on the nucleotide-binding domain. Proc Natl Acad Sci U S A 2013; 110:13386-91. [PMID: 23901103 DOI: 10.1073/pnas.1309275110] [Citation(s) in RCA: 195] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
P-glycoprotein (P-gp) is one of the best-known mediators of drug efflux-based multidrug resistance in many cancers. This validated therapeutic target is a prototypic, plasma membrane resident ATP-Binding Cassette transporter that pumps xenobiotic compounds out of cells. The large, polyspecific drug-binding pocket of P-gp recognizes a variety of structurally unrelated compounds. The transport of these drugs across the membrane is coincident with changes in the size and shape of this pocket during the course of the transport cycle. Here, we present the crystal structures of three inward-facing conformations of mouse P-gp derived from two different crystal forms. One structure has a nanobody bound to the C-terminal side of the first nucleotide-binding domain. This nanobody strongly inhibits the ATP hydrolysis activity of mouse P-gp by hindering the formation of a dimeric complex between the ATP-binding domains, which is essential for nucleotide hydrolysis. Together, these inward-facing conformational snapshots of P-gp demonstrate a range of flexibility exhibited by this transporter, which is likely an essential feature for the binding and transport of large, diverse substrates. The nanobody-bound structure also reveals a unique epitope on P-gp.
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25
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New concepts and aids to facilitate crystallization. Curr Opin Struct Biol 2013; 23:409-16. [PMID: 23578532 DOI: 10.1016/j.sbi.2013.03.003] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Revised: 03/08/2013] [Accepted: 03/13/2013] [Indexed: 12/20/2022]
Abstract
Novel tools and technologies are required to obtain structural information of difficult to crystallize complex biological systems such as membrane proteins, multiprotein assemblies, transient conformational states and intrinsically disordered proteins. One promising approach is to select a high affinity and specificity-binding partner (crystallization chaperone), form a complex with the protein of interest and crystallize the complex. Often the chaperone reduces the conformational freedom of the target protein and additionally facilitates the formation of well-ordered crystals. This review provides an update on the recent successes in chaperone-assisted crystallography. We also stress the importance of synergistic approaches involving protein engineering, crystallization chaperones and crystallization additives. Recent examples demonstrate that investment in such approaches can be key to success.
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26
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Park YJ, Hol WGJ. Explorations of linked editosome domains leading to the discovery of motifs defining conserved pockets in editosome OB-folds. J Struct Biol 2012; 180:362-73. [PMID: 22902563 PMCID: PMC3483419 DOI: 10.1016/j.jsb.2012.07.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2012] [Revised: 07/26/2012] [Accepted: 07/31/2012] [Indexed: 01/07/2023]
Abstract
Trypanosomatids form a group of protozoa which contain parasites of human, animals and plants. Several of these species cause major human diseases, including Trypanosoma brucei which is the causative agent of human African trypanosomiasis, also called sleeping sickness. These organisms have many highly unusual features including a unique U-insertion/deletion RNA editing process in the single mitochondrion. A key multi-protein complex, called the ∼20S editosome, or editosome, carries out a cascade of essential RNA-modifying reactions and contains a core of 12 different proteins of which six are the interaction proteins A1 to A6. Each of these interaction proteins comprises a C-terminal OB-fold and the smallest interaction protein A6 has been shown to interact with four other editosome OB-folds. Here we report the results of a "linked OB-fold" approach to obtain a view of how multiple OB-folds might interact in the core of the editosome. Constructs with variants of linked domains in 25 expression and co-expression experiments resulted in 13 soluble multi-OB-fold complexes. In several instances, these complexes were more homogeneous in size than those obtained from corresponding unlinked OB-folds. The crystal structure of A3(OB) linked to A6 could be elucidated and confirmed the tight interaction between these two OB domains as seen also in our recent complex of A3(OB) and A6 with nanobodies. In the current crystal structure of A3(OB) linked to A6, hydrophobic side chains reside in well-defined pockets of neighboring OB-fold domains. When analyzing the available crystal structures of editosome OB-folds, it appears that in five instances "Pocket 1" of A1(OB), A3(OB) and A6 is occupied by a hydrophobic side chain from a neighboring protein. In these three different OB-folds, Pocket 1 is formed by two conserved sequence motifs and an invariant arginine. These pockets might play a key role in the assembly or mechanism of the editosome by interacting with hydrophobic side chains from other proteins.
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Affiliation(s)
- Young-Jun Park
- Biomolecular Structure Center, Department of Biochemistry, School of Medicine, University of Washington, Seattle, WA 98195, USA
| | - Wim G. J. Hol
- Biomolecular Structure Center, Department of Biochemistry, School of Medicine, University of Washington, Seattle, WA 98195, USA,To whom correspondence should be addressed. Telephone: +1 (206) 685 7044; Fax: +1 (206) 685 7002;
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27
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Kala S, Moshiri H, Mehta V, Yip CW, Salavati R. The oligonucleotide binding (OB)-fold domain of KREPA4 is essential for stable incorporation into editosomes. PLoS One 2012; 7:e46864. [PMID: 23056494 PMCID: PMC3464273 DOI: 10.1371/journal.pone.0046864] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2012] [Accepted: 09/06/2012] [Indexed: 12/28/2022] Open
Abstract
Most mitochondrial mRNAs in trypanosomatid parasites require uridine insertion/deletion RNA editing, a process mediated by guide RNA (gRNA) and catalyzed by multi-protein complexes called editosomes. The six oligonucleotide/oligosaccharide binding (OB)-fold proteins (KREPA1-A6), are a part of the common core of editosomes. They form a network of interactions among themselves as well as with the insertion and deletion sub-complexes and are essential for the stability of the editosomes. KREPA4 and KREPA6 proteins bind gRNA in vitro and are known to interact directly in yeast two-hybrid analysis. In this study, using several approaches we show a minimal interaction surface of the KREPA4 protein that is required for this interaction. By screening a series of N- and C-terminally truncated KREPA4 fragments, we show that a predicted α-helix of KREPA4 OB-fold is required for its interaction with KREPA6. An antibody against the KREPA4 α-helix or mutations of this region can eliminate association with KREPA6; while a peptide fragment corresponding to the α-helix can independently interact with KREPA6, thereby supporting the identification of KREPA4-KREPA6 interface. We also show that the predicted OB-fold of KREPA4; independent of its interaction with gRNA, is responsible for the stable integration of KREPA4 in the editosomes, and editing complexes co-purified with the tagged OB-fold can catalyze RNA editing. Therefore, we conclude that while KREPA4 interacts with KREPA6 through the α-helix region of its OB-fold, the entire OB-fold is required for its integration in the functional editosome, through additional protein-protein interactions.
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Affiliation(s)
- Smriti Kala
- Institute of Parasitology, McGill University, Ste. Anne de Bellevue, Quebec, Canada
| | - Houtan Moshiri
- Institute of Parasitology, McGill University, Ste. Anne de Bellevue, Quebec, Canada
- Department of Biochemistry, McGill University, Montreal, Quebec, Canada
| | - Vaibhav Mehta
- Institute of Parasitology, McGill University, Ste. Anne de Bellevue, Quebec, Canada
| | - Chun Wai Yip
- Institute of Parasitology, McGill University, Ste. Anne de Bellevue, Quebec, Canada
| | - Reza Salavati
- Institute of Parasitology, McGill University, Ste. Anne de Bellevue, Quebec, Canada
- Department of Biochemistry, McGill University, Montreal, Quebec, Canada
- McGill Centre for Bioinformatics, McGill University, Montreal, Quebec, Canada
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28
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Park YJ, Budiarto T, Wu M, Pardon E, Steyaert J, Hol WGJ. The structure of the C-terminal domain of the largest editosome interaction protein and its role in promoting RNA binding by RNA-editing ligase L2. Nucleic Acids Res 2012; 40:6966-77. [PMID: 22561373 PMCID: PMC3413154 DOI: 10.1093/nar/gks369] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2012] [Revised: 04/10/2012] [Accepted: 04/11/2012] [Indexed: 12/20/2022] Open
Abstract
Trypanosomatids, such as the sleeping sickness parasite Trypanosoma brucei, contain a ∼ 20S RNA-editing complex, also called the editosome, which is required for U-insertion/deletion editing of mitochondrial mRNAs. The editosome contains a core of 12 proteins including the large interaction protein A1, the small interaction protein A6, and the editing RNA ligase L2. Using biochemical and structural data, we identified distinct domains of T. brucei A1 which specifically recognize A6 and L2. We provide evidence that an N-terminal domain of A1 interacts with the C-terminal domain of L2. The C-terminal domain of A1 appears to be required for the interaction with A6 and also plays a key role in RNA binding by the RNA-editing ligase L2 in trans. Three crystal structures of the C-terminal domain of A1 have been elucidated, each in complex with a nanobody as a crystallization chaperone. These structures permitted the identification of putative dsRNA recognition sites. Mutational analysis of conserved residues of the C-terminal domain identified Arg703, Arg731 and Arg734 as key requirements for RNA binding. The data show that the editing RNA ligase activity is modulated by a novel mechanism, i.e. by the trans-acting RNA binding C-terminal domain of A1.
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Affiliation(s)
- Young-Jun Park
- Biomolecular Structure Center, Department of Biochemistry, School of Medicine, University of Washington, Seattle, WA 98195, USA, Structural Biology Brussels, Vrije Universiteit Brussel and Department of Structural Biology, VIB, Pleinlaan 2, B-1050 Brussels, Belgium
| | - Tanya Budiarto
- Biomolecular Structure Center, Department of Biochemistry, School of Medicine, University of Washington, Seattle, WA 98195, USA, Structural Biology Brussels, Vrije Universiteit Brussel and Department of Structural Biology, VIB, Pleinlaan 2, B-1050 Brussels, Belgium
| | - Meiting Wu
- Biomolecular Structure Center, Department of Biochemistry, School of Medicine, University of Washington, Seattle, WA 98195, USA, Structural Biology Brussels, Vrije Universiteit Brussel and Department of Structural Biology, VIB, Pleinlaan 2, B-1050 Brussels, Belgium
| | - Els Pardon
- Biomolecular Structure Center, Department of Biochemistry, School of Medicine, University of Washington, Seattle, WA 98195, USA, Structural Biology Brussels, Vrije Universiteit Brussel and Department of Structural Biology, VIB, Pleinlaan 2, B-1050 Brussels, Belgium
| | - Jan Steyaert
- Biomolecular Structure Center, Department of Biochemistry, School of Medicine, University of Washington, Seattle, WA 98195, USA, Structural Biology Brussels, Vrije Universiteit Brussel and Department of Structural Biology, VIB, Pleinlaan 2, B-1050 Brussels, Belgium
| | - Wim G. J. Hol
- Biomolecular Structure Center, Department of Biochemistry, School of Medicine, University of Washington, Seattle, WA 98195, USA, Structural Biology Brussels, Vrije Universiteit Brussel and Department of Structural Biology, VIB, Pleinlaan 2, B-1050 Brussels, Belgium
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29
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Böhm C, Katari VS, Brecht M, Göringer HU. Trypanosoma brucei 20 S editosomes have one RNA substrate-binding site and execute RNA unwinding activity. J Biol Chem 2012; 287:26268-77. [PMID: 22661715 PMCID: PMC3406711 DOI: 10.1074/jbc.m112.365916] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2012] [Revised: 05/10/2012] [Indexed: 12/30/2022] Open
Abstract
Editing of mitochondrial pre-mRNAs in African trypanosomes generates full-length transcripts by the site-specific insertion and deletion of uridylate nucleotides. The reaction is catalyzed by a 0.8 MDa multienzyme complex, the editosome. Although the binding of substrate pre-edited mRNAs and cognate guide RNAs (gRNAs) represents the first step in the reaction cycle, the biochemical and biophysical details of the editosome/RNA interaction are not understood. Here we show that editosomes bind full-length substrate mRNAs with nanomolar affinity in a nonselective fashion. The complexes do not discriminate-neither kinetically nor thermodynamically-between different mitochondrial pre-mRNAs or between edited and unedited versions of the same transcript. They also bind gRNAs and gRNA/pre-mRNA hybrid RNAs with similar affinities and association rate constants. Gold labeling of editosome-bound RNA in combination with transmission electron microscopy identified a single RNA-binding site per editosome. However, atomic force microscopy of individual pre-mRNA-editosome complexes revealed that multiple editosomes can interact with one pre-mRNA. Lastly, we demonstrate a so far unknown activity of the editing machinery: editosome-bound RNA becomes unfolded by a chaperone-type RNA unwinding activity.
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MESH Headings
- Binding Sites
- Macromolecular Substances/chemistry
- Macromolecular Substances/ultrastructure
- Microscopy, Atomic Force
- Microscopy, Electron, Transmission
- Nucleic Acid Conformation
- Protein Binding
- Protozoan Proteins/chemistry
- Protozoan Proteins/ultrastructure
- RNA Processing, Post-Transcriptional
- RNA, Guide, Kinetoplastida/chemistry
- RNA, Guide, Kinetoplastida/ultrastructure
- RNA, Messenger/chemistry
- RNA, Messenger/ultrastructure
- RNA, Mitochondrial
- RNA, Protozoan/chemistry
- RNA-Binding Proteins/chemistry
- RNA-Binding Proteins/ultrastructure
- Surface Plasmon Resonance
- Trypanosoma brucei brucei/enzymology
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Affiliation(s)
- Cordula Böhm
- From the Department of Molecular Genetics, Darmstadt University of Technology, 64287 Darmstadt, Germany
| | - Venkata Subbaraju Katari
- From the Department of Molecular Genetics, Darmstadt University of Technology, 64287 Darmstadt, Germany
| | - Michael Brecht
- From the Department of Molecular Genetics, Darmstadt University of Technology, 64287 Darmstadt, Germany
| | - H. Ulrich Göringer
- From the Department of Molecular Genetics, Darmstadt University of Technology, 64287 Darmstadt, Germany
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