1
|
Sievers K, Neumann P, Sušac L, Da Vela S, Graewert M, Trowitzsch S, Svergun D, Tampé R, Ficner R. Structural and functional insights into tRNA recognition by human tRNA guanine transglycosylase. Structure 2024; 32:316-327.e5. [PMID: 38181786 DOI: 10.1016/j.str.2023.12.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 07/06/2023] [Accepted: 12/08/2023] [Indexed: 01/07/2024]
Abstract
Eukaryotic tRNA guanine transglycosylase (TGT) is an RNA-modifying enzyme which catalyzes the base exchange of the genetically encoded guanine 34 of tRNAsAsp,Asn,His,Tyr for queuine, a hypermodified 7-deazaguanine derivative. Eukaryotic TGT is a heterodimer comprised of a catalytic and a non-catalytic subunit. While binding of the tRNA anticodon loop to the active site is structurally well understood, the contribution of the non-catalytic subunit to tRNA binding remained enigmatic, as no complex structure with a complete tRNA was available. Here, we report a cryo-EM structure of eukaryotic TGT in complex with a complete tRNA, revealing the crucial role of the non-catalytic subunit in tRNA binding. We decipher the functional significance of these additional tRNA-binding sites, analyze solution state conformation, flexibility, and disorder of apo TGT, and examine conformational transitions upon tRNA binding.
Collapse
Affiliation(s)
- Katharina Sievers
- Department of Molecular Structural Biology, GZMB, University of Göttingen, 37077 Göttingen, Germany
| | - Piotr Neumann
- Department of Molecular Structural Biology, GZMB, University of Göttingen, 37077 Göttingen, Germany
| | - Lukas Sušac
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, 60438 Frankfurt/Main, Germany
| | - Stefano Da Vela
- European Molecular Biology Laboratory, Hamburg Outstation, EMBL c/o DESY, 22607 Hamburg, Germany
| | - Melissa Graewert
- European Molecular Biology Laboratory, Hamburg Outstation, EMBL c/o DESY, 22607 Hamburg, Germany
| | - Simon Trowitzsch
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, 60438 Frankfurt/Main, Germany
| | - Dmitri Svergun
- European Molecular Biology Laboratory, Hamburg Outstation, EMBL c/o DESY, 22607 Hamburg, Germany
| | - Robert Tampé
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, 60438 Frankfurt/Main, Germany
| | - Ralf Ficner
- Department of Molecular Structural Biology, GZMB, University of Göttingen, 37077 Göttingen, Germany; Cluster of Excellence "Multiscale Bioimaging: From Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, 37075 Göttingen, Germany.
| |
Collapse
|
2
|
Sekulovski S, Sušac L, Stelzl LS, Tampé R, Trowitzsch S. Structural basis of substrate recognition by human tRNA splicing endonuclease TSEN. Nat Struct Mol Biol 2023:10.1038/s41594-023-00992-y. [PMID: 37231152 DOI: 10.1038/s41594-023-00992-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 04/06/2023] [Indexed: 05/27/2023]
Abstract
Heterotetrameric human transfer RNA (tRNA) splicing endonuclease TSEN catalyzes intron excision from precursor tRNAs (pre-tRNAs), utilizing two composite active sites. Mutations in TSEN and its associated RNA kinase CLP1 are linked to the neurodegenerative disease pontocerebellar hypoplasia (PCH). Despite the essential function of TSEN, the three-dimensional assembly of TSEN-CLP1, the mechanism of substrate recognition, and the structural consequences of disease mutations are not understood in molecular detail. Here, we present single-particle cryogenic electron microscopy reconstructions of human TSEN with intron-containing pre-tRNAs. TSEN recognizes the body of pre-tRNAs and pre-positions the 3' splice site for cleavage by an intricate protein-RNA interaction network. TSEN subunits exhibit large unstructured regions flexibly tethering CLP1. Disease mutations localize far from the substrate-binding interface and destabilize TSEN. Our work delineates molecular principles of pre-tRNA recognition and cleavage by human TSEN and rationalizes mutations associated with PCH.
Collapse
Affiliation(s)
- Samoil Sekulovski
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Lukas Sušac
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Lukas S Stelzl
- Faculty of Biology, Johannes Gutenberg University Mainz, Mainz, Germany
- KOMET 1, Institute of Physics, Johannes Gutenberg University Mainz, Mainz, Germany
- Institute of Molecular Biology (IMB), Mainz, Germany
| | - Robert Tampé
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Simon Trowitzsch
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Frankfurt am Main, Germany.
| |
Collapse
|
3
|
Sušac L, Vuong MT, Thomas C, von Bülow S, O'Brien-Ball C, Santos AM, Fernandes RA, Hummer G, Tampé R, Davis SJ. Structure of a fully assembled tumor-specific T cell receptor ligated by pMHC. Cell 2022; 185:3201-3213.e19. [PMID: 35985289 PMCID: PMC9630439 DOI: 10.1016/j.cell.2022.07.010] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 04/05/2022] [Accepted: 07/15/2022] [Indexed: 12/12/2022]
Abstract
The T cell receptor (TCR) expressed by T lymphocytes initiates protective immune responses to pathogens and tumors. To explore the structural basis of how TCR signaling is initiated when the receptor binds to peptide-loaded major histocompatibility complex (pMHC) molecules, we used cryogenic electron microscopy to determine the structure of a tumor-reactive TCRαβ/CD3δγε2ζ2 complex bound to a melanoma-specific human class I pMHC at 3.08 Å resolution. The antigen-bound complex comprises 11 subunits stabilized by multivalent interactions across three structural layers, with clustered membrane-proximal cystines stabilizing the CD3-εδ and CD3-εγ heterodimers. Extra density sandwiched between transmembrane helices reveals the involvement of sterol lipids in TCR assembly. The geometry of the pMHC/TCR complex suggests that efficient TCR scanning of pMHC requires accurate pre-positioning of T cell and antigen-presenting cell membranes. Comparisons of the ligand-bound and unliganded receptors, along with molecular dynamics simulations, indicate that TCRs can be triggered in the absence of spontaneous structural rearrangements.
Collapse
Affiliation(s)
- Lukas Sušac
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt am Main, Germany
| | - Mai T Vuong
- Radcliffe Department of Medicine, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DS, UK; Medical Research Council Human Immunology Unit, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DS, UK
| | - Christoph Thomas
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt am Main, Germany
| | - Sören von Bülow
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, Max-von-Laue-Str. 3, 60438 Frankfurt am Main, Germany
| | - Caitlin O'Brien-Ball
- Radcliffe Department of Medicine, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DS, UK; Medical Research Council Human Immunology Unit, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DS, UK
| | - Ana Mafalda Santos
- Radcliffe Department of Medicine, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DS, UK; Medical Research Council Human Immunology Unit, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DS, UK
| | - Ricardo A Fernandes
- Radcliffe Department of Medicine, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DS, UK; Medical Research Council Human Immunology Unit, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DS, UK
| | - Gerhard Hummer
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, Max-von-Laue-Str. 3, 60438 Frankfurt am Main, Germany; Institute of Biophysics, Goethe University Frankfurt, Max-von-Laue-Str. 1, 60438 Frankfurt am Main, Germany
| | - Robert Tampé
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt am Main, Germany.
| | - Simon J Davis
- Radcliffe Department of Medicine, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DS, UK; Medical Research Council Human Immunology Unit, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DS, UK.
| |
Collapse
|
4
|
Abstract
Telomerase is a DNA polymerase that extends the 3' ends of chromosomes by processively synthesizing multiple telomeric repeats. It is a unique ribonucleoprotein (RNP) containing a specialized telomerase reverse transcriptase (TERT) and telomerase RNA (TER) with its own template and other elements required with TERT for activity (catalytic core), as well as species-specific TER-binding proteins important for biogenesis and assembly (core RNP); other proteins bind telomerase transiently or constitutively to allow association of telomerase and other proteins with telomere ends for regulation of DNA synthesis. Here we describe how nuclear magnetic resonance (NMR) spectroscopy and X-ray crystallography of TER and protein domains helped define the structure and function of the core RNP, laying the groundwork for interpreting negative-stain and cryo electron microscopy (cryo-EM) density maps of Tetrahymena thermophila and human telomerase holoenzymes. As the resolution has improved from ∼30 Å to ∼5 Å, these studies have provided increasingly detailed information on telomerase architecture and mechanism.
Collapse
Affiliation(s)
- Yaqiang Wang
- Department of Chemistry and Biochemistry, University of California Los Angeles (UCLA), Los Angeles, California 90095-1569
| | - Lukas Sušac
- Department of Chemistry and Biochemistry, University of California Los Angeles (UCLA), Los Angeles, California 90095-1569
| | - Juli Feigon
- Department of Chemistry and Biochemistry, University of California Los Angeles (UCLA), Los Angeles, California 90095-1569
| |
Collapse
|
5
|
Jiang J, Wang Y, Sušac L, Chan H, Basu R, Zhou ZH, Feigon J. Structure of Telomerase with Telomeric DNA. Cell 2018; 173:1179-1190.e13. [PMID: 29775593 PMCID: PMC5995583 DOI: 10.1016/j.cell.2018.04.038] [Citation(s) in RCA: 100] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 04/22/2018] [Accepted: 04/26/2018] [Indexed: 01/05/2023]
Abstract
Telomerase is an RNA-protein complex (RNP) that extends telomeric DNA at the 3' ends of chromosomes using its telomerase reverse transcriptase (TERT) and integral template-containing telomerase RNA (TER). Its activity is a critical determinant of human health, affecting aging, cancer, and stem cell renewal. Lack of atomic models of telomerase, particularly one with DNA bound, has limited our mechanistic understanding of telomeric DNA repeat synthesis. We report the 4.8 Å resolution cryoelectron microscopy structure of active Tetrahymena telomerase bound to telomeric DNA. The catalytic core is an intricately interlocked structure of TERT and TER, including a previously structurally uncharacterized TERT domain that interacts with the TEN domain to physically enclose TER and regulate activity. This complete structure of a telomerase catalytic core and its interactions with telomeric DNA from the template to telomere-interacting p50-TEB complex provides unanticipated insights into telomerase assembly and catalytic cycle and a new paradigm for a reverse transcriptase RNP.
Collapse
Affiliation(s)
- Jiansen Jiang
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095, USA; Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA; California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Yaqiang Wang
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Lukas Sušac
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Henry Chan
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Ritwika Basu
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Z Hong Zhou
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA; California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA.
| | - Juli Feigon
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095, USA.
| |
Collapse
|
6
|
Sušac L, O'Connor C, Stevens RC, Wüthrich K. In-Membrane Chemical Modification (IMCM) for Site-Specific Chromophore Labeling of GPCRs. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201508506] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
|
7
|
Sušac L, O'Connor C, Stevens RC, Wüthrich K. In-Membrane Chemical Modification (IMCM) for Site-Specific Chromophore Labeling of GPCRs. Angew Chem Int Ed Engl 2015; 54:15246-9. [PMID: 26545333 DOI: 10.1002/anie.201508506] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Indexed: 11/08/2022]
Abstract
We present in-membrane chemical modification (IMCM) for obtaining selective chromophore labeling of intracellular surface cysteines in G-protein-coupled receptors (GPCRs) with minimal mutagenesis. This method takes advantage of the natural protection of most cysteines by the membrane environment. Practical use of IMCM is illustrated with the site-specific introduction of chromophores for NMR and fluorescence spectroscopy in the human κ-opioid receptor (KOR) and the human A2A adenosine receptor (A2A AR). IMCM is applicable to a wide range of in vitro studies of GPCRs, including single-molecule spectroscopy, and is a promising platform for in-cell spectroscopy experiments.
Collapse
Affiliation(s)
- Lukas Sušac
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037 (USA)
| | - Casey O'Connor
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037 (USA).,Departments of Biological Sciences and Chemistry, Bridge Institute, University of Southern California, 3430 South Vermont Avenue, Los Angeles, CA 90089 (USA)
| | - Raymond C Stevens
- Departments of Biological Sciences and Chemistry, Bridge Institute, University of Southern California, 3430 South Vermont Avenue, Los Angeles, CA 90089 (USA)
| | - Kurt Wüthrich
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037 (USA). .,Skaggs Institute of Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037 (USA). .,Institute of Molecular Biology and Biophysics, ETH Zurich, Otto-Stern-Weg 5, 8093 Zurich (Switzerland).
| |
Collapse
|
8
|
Sušac L, Horst R, Wüthrich K. Solution-NMR characterization of outer-membrane protein A from E. coli in lipid bilayer nanodiscs and detergent micelles. Chembiochem 2014; 15:995-1000. [PMID: 24692152 DOI: 10.1002/cbic.201300729] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2013] [Indexed: 01/08/2023]
Abstract
X-ray crystallography and solution NMR of detergent-reconstituted OmpA (outer membrane protein A from E. coli) had shown that this protein forms an eight-stranded transmembrane β-barrel, but only limited information was obtained for the extracellular loops. In NMR studies of OmpA in two different detergent micelles, "NMR-invisible" amino acid residues in-between the extracellular loops and the β-barrel prevented complete structural characterization. Here, we show that this NMR-invisible ring around the β-barrel of OmpA is also present in lipid bilayer nanodiscs and in mixed micelles with a third detergent, thus suggesting that the implicated rate processes have a functional role rather than representing an artifact of the protein reconstitution. In addition to sequence-specific NMR assignments for OmpA in the nanodiscs, the present results are based on a protocol of micro-coil TROSY- and CRINEPT-type NMR diffusion measurements for studying the hydrodynamic properties and the foldedness of [(2)H,(15)N]-labeled membrane proteins in nanodiscs. This protocol can be applied under conditions closely similar to those used for NMR structure determinations or crystallization trials.
Collapse
Affiliation(s)
- Lukas Sušac
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037 (USA)
| | | | | |
Collapse
|