1
|
Grabowski M, Cooper DR, Brzezinski D, Macnar JM, Shabalin IG, Cymborowski M, Otwinowski Z, Minor W. Synchrotron Radiation as a Tool for Macromolecular X-Ray Crystallography: a XXI Century Perspective. NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH. SECTION B, BEAM INTERACTIONS WITH MATERIALS AND ATOMS 2021; 489:30-40. [PMID: 33603257 PMCID: PMC7886262 DOI: 10.1016/j.nimb.2020.12.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Intense X-rays available at powerful synchrotron beamlines provide macromolecular crystallographers with an incomparable tool for investigating biological phenomena on an atomic scale. The resulting insights into the mechanism's underlying biological processes have played an essential role and shaped biomedical sciences during the last 30 years, considered the "golden age" of structural biology. In this review, we analyze selected aspects of the impact of synchrotron radiation on structural biology. Synchrotron beamlines have been used to determine over 70% of all macromolecular structures deposited into the Protein Data Bank (PDB). These structures were deposited by over 13,000 different research groups. Interestingly, despite the impressive advances in synchrotron technologies, the median resolution of macromolecular structures determined using synchrotrons has remained constant throughout the last 30 years, at about 2 Å. Similarly, the median times from the data collection to the deposition and release have not changed significantly. We describe challenges to reproducibility related to recording all relevant data and metadata during the synchrotron experiments, including diffraction images. Finally, we discuss some of the recent opinions suggesting a diminishing importance of X-ray crystallography due to impressive advances in Cryo-EM and theoretical modeling. We believe that synchrotrons of the future will increasingly evolve towards a life science center model, where X-ray crystallography, Cryo-EM, and other experimental and computational resources and knowledge are encompassed within a versatile research facility. The recent response of crystallographers to the COVID-19 pandemic suggests that X-ray crystallography conducted at synchrotron beamlines will continue to play an essential role in structural biology and drug discovery for years to come.
Collapse
Affiliation(s)
- Marek Grabowski
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA22903, USA
| | - David R. Cooper
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA22903, USA
| | - Dariusz Brzezinski
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA22903, USA
- Institute of Computing Science, Poznan University of Technology, Poznan, Poland
- Center for Biocrystallographic Research, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan, Poland
| | - Joanna M. Macnar
- College of Inter-Faculty Individual Studies in Mathematics and Natural Sciences, University of Warsaw, Warsaw, Poland
- Faculty of Chemistry, Biological and Chemical Research Center, University of Warsaw, Warsaw, Poland
| | - Ivan G. Shabalin
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA22903, USA
| | - Marcin Cymborowski
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA22903, USA
| | - Zbyszek Otwinowski
- Department of Biophysics, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Wladek Minor
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA22903, USA
| |
Collapse
|
2
|
Subramaniam JD, Lee SK, Chinapang P, Praneeth VKK, Okamura M, Kondo M, Masaoka S, Woi PM. Synthesis and structural characterization of centrosymmetric multinuclear nickel(II) complexes with neutral tetradentate N6-ligand. TRANSIT METAL CHEM 2021. [DOI: 10.1007/s11243-020-00441-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
3
|
Liebschner D, Afonine PV, Moriarty NW, Poon BK, Chen VB, Adams PD. CERES: a cryo-EM re-refinement system for continuous improvement of deposited models. Acta Crystallogr D Struct Biol 2021; 77:48-61. [PMID: 33404525 PMCID: PMC7787109 DOI: 10.1107/s2059798320015879] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Accepted: 12/03/2020] [Indexed: 11/10/2022] Open
Abstract
The field of electron cryomicroscopy (cryo-EM) has advanced quickly in recent years as the result of numerous technological and methodological developments. This has led to an increase in the number of atomic structures determined using this method. Recently, several tools for the analysis of cryo-EM data and models have been developed within the Phenix software package, such as phenix.real_space_refine for the refinement of atomic models against real-space maps. Also, new validation metrics have been developed for low-resolution cryo-EM models. To understand the quality of deposited cryo-EM structures and how they might be improved, models deposited in the Protein Data Bank that have map resolutions of better than 5 Å were automatically re-refined using current versions of Phenix tools. The results are available on a publicly accessible web page (https://cci.lbl.gov/ceres). The implementation of a Cryo-EM Re-refinement System (CERES) for the improvement of models deposited in the wwPDB, and the results of the re-refinements, are described. Based on these results, contents are proposed for a `cryo-EM Table 1', which summarizes experimental details and validation metrics in a similar way to `Table 1' in crystallography. The consistent use of robust metrics for the evaluation of cryo-EM models and data should accompany every structure deposition and be reported in scientific publications.
Collapse
Affiliation(s)
- Dorothee Liebschner
- Molecular Biosciences and Integrated Bioimaging, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA
| | - Pavel V. Afonine
- Molecular Biosciences and Integrated Bioimaging, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA
| | - Nigel W. Moriarty
- Molecular Biosciences and Integrated Bioimaging, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA
| | - Billy K. Poon
- Molecular Biosciences and Integrated Bioimaging, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA
| | - Vincent B. Chen
- Department of Biochemistry, Duke University, Durham, NC 27710, USA
| | - Paul D. Adams
- Molecular Biosciences and Integrated Bioimaging, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA
- Department of Bioengineering, University of California Berkeley, Berkeley, CA 94720, USA
| |
Collapse
|
4
|
Brzezinski D, Dauter Z, Minor W, Jaskolski M. On the evolution of the quality of macromolecular models in the PDB. FEBS J 2020; 287:2685-2698. [PMID: 32311227 PMCID: PMC7340579 DOI: 10.1111/febs.15314] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2019] [Revised: 03/02/2020] [Accepted: 03/26/2020] [Indexed: 01/06/2023]
Abstract
Crystallographic models of biological macromolecules have been ranked using the quality criteria associated with them in the Protein Data Bank (PDB). The outcomes of this quality analysis have been correlated with time and with the journals that published papers based on those models. The results show that the overall quality of PDB structures has substantially improved over the last ten years, but this period of progress was preceded by several years of stagnation or even depression. Moreover, the study shows that the historically observed negative correlation between journal impact and the quality of structural models presented therein seems to disappear as time progresses.
Collapse
Affiliation(s)
- Dariusz Brzezinski
- Center for Biocrystallographic ResearchInstitute of Bioorganic ChemistryPolish Academy of SciencesPoznanPoland
- Institute of Computing SciencePoznan University of TechnologyPoland
- Center for Artificial Intelligence and Machine LearningPoznan University of TechnologyPoland
- Department of Molecular Physiology and Biological PhysicsUniversity of VirginiaCharlottesvilleVAUSA
| | - Zbigniew Dauter
- Synchrotron Radiation Research SectionMacromolecular Crystallography LaboratoryNational Cancer InstituteArgonne National LaboratoryArgonneILUSA
| | - Wladek Minor
- Department of Molecular Physiology and Biological PhysicsUniversity of VirginiaCharlottesvilleVAUSA
| | - Mariusz Jaskolski
- Center for Biocrystallographic ResearchInstitute of Bioorganic ChemistryPolish Academy of SciencesPoznanPoland
- Department of CrystallographyFaculty of ChemistryA. Mickiewicz UniversityPoznanPoland
| |
Collapse
|
5
|
Wlodawer A, Dauter Z, Porebski PJ, Minor W, Stanfield R, Jaskolski M, Pozharski E, Weichenberger CX, Rupp B. Detect, correct, retract: How to manage incorrect structural models. FEBS J 2018; 285:444-466. [PMID: 29113027 PMCID: PMC5799025 DOI: 10.1111/febs.14320] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2017] [Accepted: 11/01/2017] [Indexed: 12/13/2022]
Abstract
The massive technical and computational progress of biomolecular crystallography has generated some adverse side effects. Most crystal structure models, produced by crystallographers or well-trained structural biologists, constitute useful sources of information, but occasional extreme outliers remind us that the process of structure determination is not fail-safe. The occurrence of severe errors or gross misinterpretations raises fundamental questions: Why do such aberrations emerge in the first place? How did they evade the sophisticated validation procedures which often produce clear and dire warnings, and why were severe errors not noticed by the depositors themselves, their supervisors, referees and editors? Once detected, what can be done to either correct, improve or eliminate such models? How do incorrect models affect the underlying claims or biomedical hypotheses they were intended, but failed, to support? What is the long-range effect of the propagation of such errors? And finally, what mechanisms can be envisioned to restore the validity of the scientific record and, if necessary, retract publications that are clearly invalidated by the lack of experimental evidence? We suggest that cognitive bias and flawed epistemology are likely at the root of the problem. By using examples from the published literature and from public repositories such as the Protein Data Bank, we provide case summaries to guide correction or improvement of structural models. When strong claims are unsustainable because of a deficient crystallographic model, removal of such a model and even retraction of the affected publication are necessary to restore the integrity of the scientific record.
Collapse
Affiliation(s)
- Alexander Wlodawer
- Protein Structure Section, Macromolecular Crystallography Laboratory, National Cancer Institute, Frederick, MD, 21702, USA
| | - Zbigniew Dauter
- Synchrotron Radiation Research Section, Macromolecular Crystallography Laboratory, National Cancer Institute, Argonne National Laboratory, Argonne, IL 60439, USA
| | - Przemyslaw J. Porebski
- Department of Molecular Physiology and Biological Physics, University of Virginia, 1340 Jefferson Park Avenue, Charlottesville, VA, 22908, USA
| | - Wladek Minor
- Department of Molecular Physiology and Biological Physics, University of Virginia, 1340 Jefferson Park Avenue, Charlottesville, VA, 22908, USA
| | - Robyn Stanfield
- Department of Structural and Computational Biology, BCC206, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Mariusz Jaskolski
- Department of Crystallography, Faculty of Chemistry, A. Mickiewicz University, Umultowska 89b, Poznan, 61-614, Poland
- Center for Biocrystallographic Research, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, Poznan, 61-704, Poland
| | - Edwin Pozharski
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD, USA
| | | | - Bernhard Rupp
- CVMO, k.-k.Hofkristallamt, 991 Audrey Place, Vista, CA, 92084, USA
- Department of Genetic Epidemiology, Medical University Innsbruck, Schöpfstr. 41, Innsbruck, 6020, Austria
| |
Collapse
|
6
|
Salunke DM, Nair DT. Macromolecular structures: Quality assessment and biological interpretation. IUBMB Life 2017; 69:563-571. [DOI: 10.1002/iub.1640] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 04/25/2017] [Indexed: 02/05/2023]
Affiliation(s)
- Dinakar M. Salunke
- International Centre for Genetic Engineering and Biotechnology; Aruna Asaf Ali Marg; New Delhi India
| | - Deepak T. Nair
- Regional Centre for Biotechnology, NCR Biotech Science Cluster; 3rd Milestone, Faridabad-Gurgaon Expressway Faridabad Haryana India
| |
Collapse
|
7
|
Naschberger A, Fürnrohr BG, Lenac Rovis T, Malic S, Scheffzek K, Dieplinger H, Rupp B. The N14 anti-afamin antibody Fab: a rare V L1 CDR glycosylation, crystallographic re-sequencing, molecular plasticity and conservative versus enthusiastic modelling. Acta Crystallogr D Struct Biol 2016; 72:1267-1280. [PMID: 27917827 PMCID: PMC5137224 DOI: 10.1107/s205979831601723x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Accepted: 10/26/2016] [Indexed: 12/31/2022] Open
Abstract
The monoclonal antibody N14 is used as a detection antibody in ELISA kits for the human glycoprotein afamin, a member of the albumin family, which has recently gained interest in the capture and stabilization of Wnt signalling proteins, and for its role in metabolic syndrome and papillary thyroid carcinoma. As a rare occurrence, the N14 Fab is N-glycosylated at Asn26L at the onset of the VL1 antigen-binding loop, with the α-1-6 core fucosylated complex glycan facing out of the L1 complementarity-determining region. The crystal structures of two non-apparent (pseudo) isomorphous crystals of the N14 Fab were analyzed, which differ significantly in the elbow angles, thereby cautioning against the overinterpretation of domain movements upon antigen binding. In addition, the map quality at 1.9 Å resolution was sufficient to crystallographically re-sequence the variable VL and VH domains and to detect discrepancies in the hybridoma-derived sequence. Finally, a conservatively refined parsimonious model is presented and its statistics are compared with those from a less conservatively built model that has been modelled more enthusiastically. Improvements to the PDB validation reports affecting ligands, clashscore and buried surface calculations are suggested.
Collapse
Affiliation(s)
- Andreas Naschberger
- Division of Biological Chemistry, Medical University of Innsbruck, Innrain 80, 6020 Innsbruck, Austria
| | - Barbara G. Fürnrohr
- Division of Biological Chemistry, Medical University of Innsbruck, Innrain 80, 6020 Innsbruck, Austria
| | - Tihana Lenac Rovis
- Center for Proteomics, University of Rijeka, B. Branchetta 20, 51000 Rijeka, Croatia
| | - Suzana Malic
- Center for Proteomics, University of Rijeka, B. Branchetta 20, 51000 Rijeka, Croatia
| | - Klaus Scheffzek
- Division of Biological Chemistry, Medical University of Innsbruck, Innrain 80, 6020 Innsbruck, Austria
| | - Hans Dieplinger
- Division of Genetic Epidemiology, Medical University of Innsbruck, Schöpfstrasse 41, 6020 Innsbruck, Austria
- Vitateq Biotechnology GmbH, Innrain 66, 6020 Innsbruck, Austria
| | - Bernhard Rupp
- Division of Genetic Epidemiology, Medical University of Innsbruck, Schöpfstrasse 41, 6020 Innsbruck, Austria
- CVMO, k.-k. Hofkristallamt, 991 Audrey Place, Vista, CA 92084, USA
| |
Collapse
|
8
|
Grabowski M, Langner KM, Cymborowski M, Porebski PJ, Sroka P, Zheng H, Cooper DR, Zimmerman MD, Elsliger MA, Burley SK, Minor W. A public database of macromolecular diffraction experiments. Acta Crystallogr D Struct Biol 2016; 72:1181-1193. [PMID: 27841751 PMCID: PMC5108346 DOI: 10.1107/s2059798316014716] [Citation(s) in RCA: 96] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Accepted: 09/17/2016] [Indexed: 12/28/2022] Open
Abstract
The low reproducibility of published experimental results in many scientific disciplines has recently garnered negative attention in scientific journals and the general media. Public transparency, including the availability of `raw' experimental data, will help to address growing concerns regarding scientific integrity. Macromolecular X-ray crystallography has led the way in requiring the public dissemination of atomic coordinates and a wealth of experimental data, making the field one of the most reproducible in the biological sciences. However, there remains no mandate for public disclosure of the original diffraction data. The Integrated Resource for Reproducibility in Macromolecular Crystallography (IRRMC) has been developed to archive raw data from diffraction experiments and, equally importantly, to provide related metadata. Currently, the database of our resource contains data from 2920 macromolecular diffraction experiments (5767 data sets), accounting for around 3% of all depositions in the Protein Data Bank (PDB), with their corresponding partially curated metadata. IRRMC utilizes distributed storage implemented using a federated architecture of many independent storage servers, which provides both scalability and sustainability. The resource, which is accessible via the web portal at http://www.proteindiffraction.org, can be searched using various criteria. All data are available for unrestricted access and download. The resource serves as a proof of concept and demonstrates the feasibility of archiving raw diffraction data and associated metadata from X-ray crystallographic studies of biological macromolecules. The goal is to expand this resource and include data sets that failed to yield X-ray structures in order to facilitate collaborative efforts that will improve protein structure-determination methods and to ensure the availability of `orphan' data left behind for various reasons by individual investigators and/or extinct structural genomics projects.
Collapse
Affiliation(s)
- Marek Grabowski
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA 22904, USA
| | - Karol M. Langner
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA 22904, USA
| | - Marcin Cymborowski
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA 22904, USA
| | - Przemyslaw J. Porebski
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA 22904, USA
- Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, Niezapominajek 8, 30-239 Cracow, Poland
| | - Piotr Sroka
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA 22904, USA
| | - Heping Zheng
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA 22904, USA
| | - David R. Cooper
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA 22904, USA
| | - Matthew D. Zimmerman
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA 22904, USA
| | - Marc-André Elsliger
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 90237, USA
| | - Stephen K. Burley
- RCSB Protein Data Bank; Center for Integrative Proteomics Research; Institute for Quantitative Biomedicine; Rutgers Cancer Institute of New Jersey; Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
- San Diego Supercomputer Center and Skaggs School of Pharmacological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Wladek Minor
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA 22904, USA
| |
Collapse
|
9
|
Cole JC, Korb O, Olsson TSG, Liebeschuetz J. The Basis for Target-Based Virtual Screening: Protein Structures. ACTA ACUST UNITED AC 2011. [DOI: 10.1002/9783527633326.ch4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
|
10
|
To automate or not to automate: this is the question. ACTA ACUST UNITED AC 2010; 11:211-21. [PMID: 20526815 PMCID: PMC2921494 DOI: 10.1007/s10969-010-9092-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2009] [Accepted: 05/14/2010] [Indexed: 11/26/2022]
Abstract
New protocols and instrumentation significantly boost the outcome of structural biology, which has resulted in significant growth in the number of deposited Protein Data Bank structures. However, even an enormous increase of the productivity of a single step of the structure determination process may not significantly shorten the time between clone and deposition or publication. For example, in a medium size laboratory equipped with the LabDB and HKL-3000 systems, we show that automation of some (and integration of all) steps of the X-ray structure determination pathway is critical for laboratory productivity. Moreover, we show that the lag period after which the impact of a technology change is observed is longer than expected.
Collapse
|
11
|
Ginzinger SW, Weichenberger CX, Sippl MJ. Detection of unrealistic molecular environments in protein structures based on expected electron densities. JOURNAL OF BIOMOLECULAR NMR 2010; 47:33-40. [PMID: 20405167 PMCID: PMC2859164 DOI: 10.1007/s10858-010-9408-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2009] [Accepted: 03/10/2010] [Indexed: 05/11/2023]
Abstract
Understanding the relationship between protein structure and biological function is a central theme in structural biology. Advances are severely hampered by errors in experimentally determined protein structures. Detection and correction of such errors is therefore of utmost importance. Electron densities in molecular structures obey certain rules which depend on the molecular environment. Here we present and discuss a new approach that relates electron densities computed from a structural model to densities expected from prior observations on identical or closely related molecular environments. Strong deviations of computed from expected densities reveal unrealistic molecular structures. Most importantly, structure analysis and error detection are independent of experimental data and hence may be applied to any structural model. The comparison to state-of-the-art methods reveals that our approach is able to identify errors that formerly remained undetected. The new technique, called RefDens, is accessible as a public web service at http://refdens.services.came.sbg.ac.at.
Collapse
Affiliation(s)
- Simon W. Ginzinger
- Department of Molecular Biology, Division of Bioinformatics, Center of Applied Molecular Engineering, University of Salzburg, Hellbrunnerstr. 34, 5020 Salzburg, Austria
| | - Christian X. Weichenberger
- Department of Molecular Biology, Division of Bioinformatics, Center of Applied Molecular Engineering, University of Salzburg, Hellbrunnerstr. 34, 5020 Salzburg, Austria
| | - Manfred J. Sippl
- Department of Molecular Biology, Division of Bioinformatics, Center of Applied Molecular Engineering, University of Salzburg, Hellbrunnerstr. 34, 5020 Salzburg, Austria
| |
Collapse
|
12
|
Broutin I, Jomain JB, Tallet E, van Agthoven J, Raynal B, Hoos S, Kragelund BB, Kelly PA, Ducruix A, England P, Goffin V. Crystal structure of an affinity-matured prolactin complexed to its dimerized receptor reveals the topology of hormone binding site 2. J Biol Chem 2010; 285:8422-33. [PMID: 20053995 PMCID: PMC2832991 DOI: 10.1074/jbc.m109.089128] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2009] [Revised: 12/21/2009] [Indexed: 11/06/2022] Open
Abstract
We report the first crystal structure of a 1:2 hormone.receptor complex that involves prolactin (PRL) as the ligand, at 3.8-A resolution. Stable ternary complexes were obtained by generating affinity-matured PRL variants harboring an N-terminal tail from ovine placental lactogen, a closely related PRL receptor (PRLR) ligand. This structure allows one to draw up an exhaustive inventory of the residues involved at the PRL.PRLR site 2 interface, consistent with all previously reported site-directed mutagenesis data. We propose, with this description, an interaction model involving three structural components of PRL site 2 ("three-pin plug"): the conserved glycine 129 of helix alpha3, the hydrogen bond network involving surrounding residues (glycine cavity), and the N terminus. The model provides a molecular basis for the properties of the different PRL analogs designed to date, including PRLR antagonists. Finally, comparison of our 1:2 PRL.PRLR(2) structure with those of free PRL and its 1:1 complex indicates that the structure of PRL undergoes significant changes when binding the first, but not the second receptor. This suggests that the second PRLR moiety adapts to the 1:1 complex rather than the opposite. In conclusion, this structure will be a useful guiding tool for further investigations of the molecular mechanisms involved in PRLR dimerization and activation, as well as for the optimization of PRLR antagonists, an emerging class of compounds with high therapeutic potential against breast and prostate cancer.
Collapse
Affiliation(s)
- Isabelle Broutin
- From the Laboratoire de Cristallographie et RMN Biologiques, CNRS, UMR 8015, Université Paris Descartes, 75006 Paris, France
| | - Jean-Baptiste Jomain
- INSERM, U845, Centre de Recherche “Croissance et Signalisation,” Equipe “PRL/GH Pathophysiology,” Paris F-75015, France
- the Université Paris Descartes, Faculté de Médecine Site Necker, Paris F-75015, France
| | - Estelle Tallet
- INSERM, U845, Centre de Recherche “Croissance et Signalisation,” Equipe “PRL/GH Pathophysiology,” Paris F-75015, France
- the Université Paris Descartes, Faculté de Médecine Site Necker, Paris F-75015, France
| | - Jan van Agthoven
- From the Laboratoire de Cristallographie et RMN Biologiques, CNRS, UMR 8015, Université Paris Descartes, 75006 Paris, France
| | - Bertrand Raynal
- the Institut Pasteur, Plateforme de Biophysique des Macromolécules et de leurs Interactions, Département de Biologie Structurale et Chimie, Paris F-75015, France
- the CNRS URA 2185, Paris F-75015, France, and
| | - Sylviane Hoos
- the Institut Pasteur, Plateforme de Biophysique des Macromolécules et de leurs Interactions, Département de Biologie Structurale et Chimie, Paris F-75015, France
- the CNRS URA 2185, Paris F-75015, France, and
| | - Birthe B. Kragelund
- the Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, DK-2200 Copenhagen N, Denmark
| | - Paul A. Kelly
- INSERM, U845, Centre de Recherche “Croissance et Signalisation,” Equipe “PRL/GH Pathophysiology,” Paris F-75015, France
- the Université Paris Descartes, Faculté de Médecine Site Necker, Paris F-75015, France
| | - Arnaud Ducruix
- From the Laboratoire de Cristallographie et RMN Biologiques, CNRS, UMR 8015, Université Paris Descartes, 75006 Paris, France
| | - Patrick England
- the Institut Pasteur, Plateforme de Biophysique des Macromolécules et de leurs Interactions, Département de Biologie Structurale et Chimie, Paris F-75015, France
- the CNRS URA 2185, Paris F-75015, France, and
| | - Vincent Goffin
- INSERM, U845, Centre de Recherche “Croissance et Signalisation,” Equipe “PRL/GH Pathophysiology,” Paris F-75015, France
- the Université Paris Descartes, Faculté de Médecine Site Necker, Paris F-75015, France
| |
Collapse
|
13
|
|
14
|
Urzhumtsev A, Afonine PV, Adams PD. On the use of logarithmic scales for analysis of diffraction data. ACTA CRYSTALLOGRAPHICA. SECTION D, BIOLOGICAL CRYSTALLOGRAPHY 2009; 65:1283-91. [PMID: 19966414 PMCID: PMC2789003 DOI: 10.1107/s0907444909039638] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/17/2009] [Accepted: 09/29/2009] [Indexed: 11/20/2022]
Abstract
Predictions of the possible model parameterization and of the values of model characteristics such as R factors are important for macromolecular refinement and validation protocols. One of the key parameters defining these and other values is the resolution of the experimentally measured diffraction data. The higher the resolution, the larger the number of diffraction data N(ref), the larger its ratio to the number N(at) of non-H atoms, the more parameters per atom can be used for modelling and the more precise and detailed a model can be obtained. The ratio N(ref)/N(at) was calculated for models deposited in the Protein Data Bank as a function of the resolution at which the structures were reported. The most frequent values for this distribution depend essentially linearly on resolution when the latter is expressed on a uniform logarithmic scale. This defines simple analytic formulae for the typical Matthews coefficient and for the typically allowed number of parameters per atom for crystals diffracting to a given resolution. This simple dependence makes it possible in many cases to estimate the expected resolution of the experimental data for a crystal with a given Matthews coefficient. When expressed using the same logarithmic scale, the most frequent values for R and R(free) factors and for their difference are also essentially linear across a large resolution range. The minimal R-factor values are practically constant at resolutions better than 3 A, below which they begin to grow sharply. This simple dependence on the resolution allows the prediction of expected R-factor values for unknown structures and may be used to guide model refinement and validation.
Collapse
|