1
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Wu Y, Ni MT, Wang YH, Wang C, Hou H, Zhang X, Zhou J. Structural basis of translation inhibition by a valine tRNA-derived fragment. Life Sci Alliance 2024; 7:e202302488. [PMID: 38599770 PMCID: PMC11009984 DOI: 10.26508/lsa.202302488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2023] [Revised: 03/22/2024] [Accepted: 03/22/2024] [Indexed: 04/12/2024] Open
Abstract
Translational regulation by non-coding RNAs is a mechanism commonly used by cells to fine-tune gene expression. A fragment derived from an archaeal valine tRNA (Val-tRF) has been previously identified to bind the small subunit of the ribosome and inhibit translation in Haloferax volcanii Here, we present three cryo-electron microscopy structures of Val-tRF bound to the small subunit of Sulfolobus acidocaldarius ribosomes at resolutions between 4.02 and 4.53 Å. Within these complexes, Val-tRF was observed to bind to conserved RNA-interacting sites, including the ribosomal decoding center. The binding of Val-tRF destabilizes helices h24, h44, and h45 and the anti-Shine-Dalgarno sequence of 16S rRNA. The binding position of this molecule partially overlaps with the translation initiation factor aIF1A and occludes the mRNA P-site codon. Moreover, we found that the binding of Val-tRF is associated with steric hindrance of the H69 base of 23S rRNA in the large ribosome subunit, thereby preventing 70S assembly. Our data exemplify how tRNA-derived fragments bind to ribosomes and provide new insights into the mechanisms underlying translation inhibition by Val-tRFs.
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Affiliation(s)
- Yun Wu
- Life Sciences Institute, Zhejiang University, Hangzhou, China
| | - Meng-Ting Ni
- Life Sciences Institute, Zhejiang University, Hangzhou, China
| | - Ying-Hui Wang
- Life Sciences Institute, Zhejiang University, Hangzhou, China
| | - Chen Wang
- Center for Cryo-Electron Microscopy, Zhejiang University School of Medicine, Hangzhou, China
- Department of Pathology of Sir Run Run Shaw Hospital and Department of Biophysics, Zhejiang University School of Medicine, Hangzhou, China
| | - Hai Hou
- Institute of Medical Research, Northwestern Polytechnical University, Xi'an Shaanxi, China
| | - Xing Zhang
- Center for Cryo-Electron Microscopy, Zhejiang University School of Medicine, Hangzhou, China
- Department of Pathology of Sir Run Run Shaw Hospital and Department of Biophysics, Zhejiang University School of Medicine, Hangzhou, China
| | - Jie Zhou
- Life Sciences Institute, Zhejiang University, Hangzhou, China
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2
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Seely SM, Basu RS, Gagnon MG. Mechanistic insights into the alternative ribosome recycling by HflXr. Nucleic Acids Res 2024; 52:4053-4066. [PMID: 38407413 DOI: 10.1093/nar/gkae128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Revised: 02/02/2024] [Accepted: 02/19/2024] [Indexed: 02/27/2024] Open
Abstract
During stress conditions such as heat shock and antibiotic exposure, ribosomes stall on messenger RNAs, leading to inhibition of protein synthesis. To remobilize ribosomes, bacteria use rescue factors such as HflXr, a homolog of the conserved housekeeping GTPase HflX that catalyzes the dissociation of translationally inactive ribosomes into individual subunits. Here we use time-resolved cryo-electron microscopy to elucidate the mechanism of ribosome recycling by Listeria monocytogenes HflXr. Within the 70S ribosome, HflXr displaces helix H69 of the 50S subunit and induces long-range movements of the platform domain of the 30S subunit, disrupting inter-subunit bridges B2b, B2c, B4, B7a and B7b. Our findings unveil a unique ribosome recycling strategy by HflXr which is distinct from that mediated by RRF and EF-G. The resemblance between HflXr and housekeeping HflX suggests that the alternative ribosome recycling mechanism reported here is universal in the prokaryotic kingdom.
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Affiliation(s)
- Savannah M Seely
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Ritwika S Basu
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Matthieu G Gagnon
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555, USA
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555, USA
- Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX 77555, USA
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX 77555, USA
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3
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Chadani Y, Kanamori T, Niwa T, Ichihara K, Nakayama KI, Matsumoto A, Taguchi H. Mechanistic dissection of premature translation termination induced by acidic residues-enriched nascent peptide. Cell Rep 2023; 42:113569. [PMID: 38071619 DOI: 10.1016/j.celrep.2023.113569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 10/18/2023] [Accepted: 11/24/2023] [Indexed: 12/30/2023] Open
Abstract
Ribosomes polymerize nascent peptides through repeated inter-subunit rearrangements between the classic and hybrid states. The peptidyl-tRNA, the intermediate species during translation elongation, stabilizes the translating ribosome to ensure robust continuity of elongation. However, the translation of acidic residue-rich sequences destabilizes the ribosome, leading to a stochastic premature translation cessation termed intrinsic ribosome destabilization (IRD), which is still ill-defined. Here, we dissect the molecular mechanisms underlying IRD in Escherichia coli. Reconstitution of the IRD event reveals that (1) the prolonged ribosome stalling enhances IRD-mediated translation discontinuation, (2) IRD depends on temperature, (3) the destabilized 70S ribosome complex is not necessarily split, and (4) the destabilized ribosome is subjected to peptidyl-tRNA hydrolase-mediated hydrolysis of the peptidyl-tRNA without subunit splitting or recycling factors-mediated subunit splitting. Collectively, our data indicate that the translation of acidic-rich sequences alters the conformation of the 70S ribosome to an aberrant state that allows the noncanonical premature termination.
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Affiliation(s)
- Yuhei Chadani
- Faculty of Environmental, Life, Natural Science and Technology, Okayama University, Okayama 700-8530, Japan.
| | | | - Tatsuya Niwa
- Cell Biology Center, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8503, Japan; School of Life Science and Technology, Tokyo Institute of Technology, Yokohama 226-8503, Japan
| | - Kazuya Ichihara
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan
| | - Keiichi I Nakayama
- Anticancer Strategies Laboratory, TMDU Advanced Research Institute, Tokyo Medical and Dental University, Bunkyo-ku, Tokyo 113-8510, Japan; Division of Cell Biology, Medical Institute of Bioregulation, Kyushu University, Fukuoka 812-8582, Japan
| | - Akinobu Matsumoto
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan
| | - Hideki Taguchi
- Cell Biology Center, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8503, Japan; School of Life Science and Technology, Tokyo Institute of Technology, Yokohama 226-8503, Japan.
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4
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Wang YH, Dai H, Zhang L, Wu Y, Wang J, Wang C, Xu CH, Hou H, Yang B, Zhu Y, Zhang X, Zhou J. Cryo-electron microscopy structure and translocation mechanism of the crenarchaeal ribosome. Nucleic Acids Res 2023; 51:8909-8924. [PMID: 37604686 PMCID: PMC10516650 DOI: 10.1093/nar/gkad661] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Revised: 06/29/2023] [Accepted: 08/02/2023] [Indexed: 08/23/2023] Open
Abstract
Archaeal ribosomes have many domain-specific features; however, our understanding of these structures is limited. We present 10 cryo-electron microscopy (cryo-EM) structures of the archaeal ribosome from crenarchaeota Sulfolobus acidocaldarius (Sac) at 2.7-5.7 Å resolution. We observed unstable conformations of H68 and h44 of ribosomal RNA (rRNA) in the subunit structures, which may interfere with subunit association. These subunit structures provided models for 12 rRNA expansion segments and 3 novel r-proteins. Furthermore, the 50S-aRF1 complex structure showed the unique domain orientation of aRF1, possibly explaining P-site transfer RNA (tRNA) release after translation termination. Sac 70S complexes were captured in seven distinct steps of the tRNA translocation reaction, confirming conserved structural features during archaeal ribosome translocation. In aEF2-engaged 70S ribosome complexes, 3D classification of cryo-EM data based on 30S head domain identified two new translocation intermediates with 30S head domain tilted 5-6° enabling its disengagement from the translocated tRNA and its release post-translocation. Additionally, we observed conformational changes to aEF2 during ribosome binding and switching from three different states. Our structural and biochemical data provide new insights into archaeal translation and ribosome translocation.
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Affiliation(s)
- Ying-Hui Wang
- Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Hong Dai
- Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Ling Zhang
- Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Yun Wu
- Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Jingfen Wang
- Center for Cryo-Electron Microscopy, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
- Department of Pathology of Sir Run Run Shaw Hospital, and Department of Biophysics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Chen Wang
- Center for Cryo-Electron Microscopy, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
- Department of Pathology of Sir Run Run Shaw Hospital, and Department of Biophysics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Cai-Huang Xu
- Center for Cryo-Electron Microscopy, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
- Department of Pathology of Sir Run Run Shaw Hospital, and Department of Biophysics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Hai Hou
- Institute of Medical Research, Northwestern Polytechnical University, Xi’an, Shaanxi 710072, China
| | - Bing Yang
- Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Yongqun Zhu
- Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Xing Zhang
- Center for Cryo-Electron Microscopy, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
- Department of Pathology of Sir Run Run Shaw Hospital, and Department of Biophysics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Jie Zhou
- Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058, China
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5
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Ray KK, Kinz-Thompson CD, Fei J, Wang B, Lin Q, Gonzalez RL. Entropic control of the free-energy landscape of an archetypal biomolecular machine. Proc Natl Acad Sci U S A 2023; 120:e2220591120. [PMID: 37186858 PMCID: PMC10214133 DOI: 10.1073/pnas.2220591120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2022] [Accepted: 04/17/2023] [Indexed: 05/17/2023] Open
Abstract
Biomolecular machines are complex macromolecular assemblies that utilize thermal and chemical energy to perform essential, multistep, cellular processes. Despite possessing different architectures and functions, an essential feature of the mechanisms of action of all such machines is that they require dynamic rearrangements of structural components. Surprisingly, biomolecular machines generally possess only a limited set of such motions, suggesting that these dynamics must be repurposed to drive different mechanistic steps. Although ligands that interact with these machines are known to drive such repurposing, the physical and structural mechanisms through which ligands achieve this remain unknown. Using temperature-dependent, single-molecule measurements analyzed with a time-resolution-enhancing algorithm, here, we dissect the free-energy landscape of an archetypal biomolecular machine, the bacterial ribosome, to reveal how its dynamics are repurposed to drive distinct steps during ribosome-catalyzed protein synthesis. Specifically, we show that the free-energy landscape of the ribosome encompasses a network of allosterically coupled structural elements that coordinates the motions of these elements. Moreover, we reveal that ribosomal ligands which participate in disparate steps of the protein synthesis pathway repurpose this network by differentially modulating the structural flexibility of the ribosomal complex (i.e., the entropic component of the free-energy landscape). We propose that such ligand-dependent entropic control of free-energy landscapes has evolved as a general strategy through which ligands may regulate the functions of all biomolecular machines. Such entropic control is therefore an important driver in the evolution of naturally occurring biomolecular machines and a critical consideration for the design of synthetic molecular machines.
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Affiliation(s)
- Korak Kumar Ray
- Department of Chemistry, Columbia University, New York, NY10027
| | | | - Jingyi Fei
- Department of Chemistry, Columbia University, New York, NY10027
| | - Bin Wang
- Department of Mechanical Engineering, Columbia University, New York, NY10027
| | - Qiao Lin
- Department of Mechanical Engineering, Columbia University, New York, NY10027
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6
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Han W, Peng B, Wang C, Townsend GE, Barry NA, Peske F, Goodman AL, Liu J, Rodnina MV, Groisman EA. Gut colonization by Bacteroides requires translation by an EF-G paralog lacking GTPase activity. EMBO J 2023; 42:e112372. [PMID: 36472247 PMCID: PMC9841332 DOI: 10.15252/embj.2022112372] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 11/11/2022] [Accepted: 11/11/2022] [Indexed: 12/12/2022] Open
Abstract
Protein synthesis is crucial for cell growth and survival yet one of the most energy-consuming cellular processes. How, then, do cells sustain protein synthesis under starvation conditions when energy is limited? To accelerate the translocation of mRNA-tRNAs through the ribosome, bacterial elongation factor G (EF-G) hydrolyzes energy-rich guanosine triphosphate (GTP) for every amino acid incorporated into a protein. Here, we identify an EF-G paralog-EF-G2-that supports translocation without hydrolyzing GTP in the gut commensal bacterium Bacteroides thetaiotaomicron. EF-G2's singular ability to sustain protein synthesis, albeit at slow rates, is crucial for bacterial gut colonization. EF-G2 is ~10-fold more abundant than canonical EF-G1 in bacteria harvested from murine ceca and, unlike EF-G1, specifically accumulates during carbon starvation. Moreover, we uncover a 26-residue region unique to EF-G2 that is essential for protein synthesis, EF-G2 dissociation from the ribosome, and responsible for the absence of GTPase activity. Our findings reveal how cells curb energy consumption while maintaining protein synthesis to advance fitness in nutrient-fluctuating environments.
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Affiliation(s)
- Weiwei Han
- Department of Microbial PathogenesisYale School of MedicineNew HavenCTUSA
- Yale Microbial Sciences InstituteWest HavenCTUSA
| | - Bee‐Zen Peng
- Department of Physical BiochemistryMax Planck Institute for Multidisciplinary SciencesGöttingenGermany
| | - Chunyan Wang
- Department of Microbial PathogenesisYale School of MedicineNew HavenCTUSA
- Yale Microbial Sciences InstituteWest HavenCTUSA
| | - Guy E Townsend
- Department of Microbial PathogenesisYale School of MedicineNew HavenCTUSA
- Yale Microbial Sciences InstituteWest HavenCTUSA
- Present address:
Department of Biochemistry and Molecular BiologyPenn State College of MedicineHersheyPAUSA
| | - Natasha A Barry
- Department of Microbial PathogenesisYale School of MedicineNew HavenCTUSA
- Yale Microbial Sciences InstituteWest HavenCTUSA
| | - Frank Peske
- Department of Physical BiochemistryMax Planck Institute for Multidisciplinary SciencesGöttingenGermany
| | - Andrew L Goodman
- Department of Microbial PathogenesisYale School of MedicineNew HavenCTUSA
- Yale Microbial Sciences InstituteWest HavenCTUSA
| | - Jun Liu
- Department of Microbial PathogenesisYale School of MedicineNew HavenCTUSA
- Yale Microbial Sciences InstituteWest HavenCTUSA
| | - Marina V Rodnina
- Department of Physical BiochemistryMax Planck Institute for Multidisciplinary SciencesGöttingenGermany
| | - Eduardo A Groisman
- Department of Microbial PathogenesisYale School of MedicineNew HavenCTUSA
- Yale Microbial Sciences InstituteWest HavenCTUSA
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7
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Alexpandi R, Abirami G, Murugesan B, Durgadevi R, Swasthikka RP, Cai Y, Ragupathi T, Ravi AV. Tocopherol-assisted magnetic Ag-Fe 3O 4-TiO 2 nanocomposite for photocatalytic bacterial-inactivation with elucidation of mechanism and its hazardous level assessment with zebrafish model. JOURNAL OF HAZARDOUS MATERIALS 2023; 442:130044. [PMID: 36179621 DOI: 10.1016/j.jhazmat.2022.130044] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2022] [Revised: 09/18/2022] [Accepted: 09/19/2022] [Indexed: 06/16/2023]
Abstract
In recent years, many endeavours have been prompted with photocatalytic nanomaterials by the need to eradicate pathogenic microorganisms from water bodies. Herein, a tocopherol-assisted Ag-Fe3O4-TiO2 nanocomposite (TAFTN) was synthesized for photocatalytic bacterial inactivation. The prepared TAFTN became active under sunlight due to its narrowed bandgap, inactivating the bacterial contaminants via photo-induced ROS stress. The ROS radicals destroy bacteria by creating oxidative stress, which damages the cell membrane and cellular components such as nucleic acids and proteins. For the first time, the nano-LC-MS/MS-based quantitative proteomics reveals that the disrupted proteins are involved in a variety of cellular functions; the most of these are involved in the metabolic pathway, eventually leading to bacterial death during TAFTN-photocatalysis under sunlight. Furthermore, the toxicity analysis confirmed that the inactivated bacteria seemed to have no detrimental impact on zebrafish model, showing that the disinfected water via TAFTN-photocatalysis is enormously safe. Furthermore, the TAFTN-photocatalysis successfully killed the bacterial cells in natural seawater, indicating the consistent photocatalytic efficacy when recycled repeatedly. The results of this work demonstrate that the produced nanocomposite might be a powerful recyclable and sunlight-active photocatalyst for environmental water treatment.
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Affiliation(s)
- Rajaiah Alexpandi
- Lab in Microbiology and Marine Biotechnology, Department of Biotechnology, School of Biological Sciences, Alagappa University, Karaikudi 630 003, India
| | - Gurusamy Abirami
- Lab in Microbiology and Marine Biotechnology, Department of Biotechnology, School of Biological Sciences, Alagappa University, Karaikudi 630 003, India
| | - Balaji Murugesan
- The Key Laboratory of Advanced Textile Materials and Manufacturing Technology of Ministry of Education, National Engineering Lab for Textile Fiber Materials and Processing Technology, School of Materials Science and Engineering, Zhejiang Sci-Tech University, Hangzhou 310018, PR China; Department of Mechanical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, South Korea
| | - Ravindran Durgadevi
- Lab in Microbiology and Marine Biotechnology, Department of Biotechnology, School of Biological Sciences, Alagappa University, Karaikudi 630 003, India
| | - Roshni Prithiviraj Swasthikka
- Lab in Microbiology and Marine Biotechnology, Department of Biotechnology, School of Biological Sciences, Alagappa University, Karaikudi 630 003, India
| | - Yurong Cai
- The Key Laboratory of Advanced Textile Materials and Manufacturing Technology of Ministry of Education, National Engineering Lab for Textile Fiber Materials and Processing Technology, School of Materials Science and Engineering, Zhejiang Sci-Tech University, Hangzhou 310018, PR China
| | - Thennarasu Ragupathi
- Lab in Microbiology and Marine Biotechnology, Department of Biotechnology, School of Biological Sciences, Alagappa University, Karaikudi 630 003, India
| | - Arumugam Veera Ravi
- Lab in Microbiology and Marine Biotechnology, Department of Biotechnology, School of Biological Sciences, Alagappa University, Karaikudi 630 003, India.
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8
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Hassan A, Whitford PC. Identifying Strategies to Experimentally Probe Multidimensional Dynamics in the Ribosome. J Phys Chem B 2022; 126:8460-8471. [PMID: 36256879 DOI: 10.1021/acs.jpcb.2c05706] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The ribosome is a complex biomolecular machine that utilizes large-scale conformational rearrangements to synthesize proteins. For example, during the elongation cycle, the "head" domain of the ribosomal small subunit (SSU) is known to undergo transient rotation events that allow for movement of tRNA molecules (i.e., translocation). While the head may exhibit rigid-body-like properties, the precise relationship between experimentally accessible probes and multidimensional rotations has yet to be established. To address this gap, we perform molecular dynamics simulations of the translocation step of the elongation cycle in the ribosome, where the SSU head spontaneously undergoes rotation and tilt-like motions. With this data set (1250 simulated events), we used statistical and information-theory-based measures to identify possible single-molecule probes that can isolate SSU head rotation and head tilting. This analysis provides a molecular interpretation for previous single-molecule measurements, while establishing a framework for the design of next-generation experiments that may precisely probe the mechanistic and kinetic aspects of the ribosome.
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Affiliation(s)
- Asem Hassan
- Department of Physics, Northeastern University, Dana Research Center 111, 360 Huntington Avenue, Boston, Massachusetts02115, United States.,Center for Theoretical Biological Physics, Northeastern University, 360 Huntington Avenue, Boston, Massachusetts02115, United States
| | - Paul C Whitford
- Department of Physics, Northeastern University, Dana Research Center 111, 360 Huntington Avenue, Boston, Massachusetts02115, United States.,Center for Theoretical Biological Physics, Northeastern University, 360 Huntington Avenue, Boston, Massachusetts02115, United States
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9
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Nishima W, Girodat D, Holm M, Rundlet EJ, Alejo JL, Fischer K, Blanchard SC, Sanbonmatsu KY. Hyper-swivel head domain motions are required for complete mRNA-tRNA translocation and ribosome resetting. Nucleic Acids Res 2022; 50:8302-8320. [PMID: 35808938 DOI: 10.1093/nar/gkac597] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 06/15/2022] [Accepted: 07/05/2022] [Indexed: 11/14/2022] Open
Abstract
Translocation of messenger RNA (mRNA) and transfer RNA (tRNA) substrates through the ribosome during protein synthesis, an exemplar of directional molecular movement in biology, entails a complex interplay of conformational, compositional, and chemical changes. The molecular determinants of early translocation steps have been investigated rigorously. However, the elements enabling the ribosome to complete translocation and reset for subsequent protein synthesis reactions remain poorly understood. Here, we have combined molecular simulations with single-molecule fluorescence resonance energy transfer imaging to gain insights into the rate-limiting events of the translocation mechanism. We find that diffusive motions of the ribosomal small subunit head domain to hyper-swivelled positions, governed by universally conserved rRNA, can maneuver the mRNA and tRNAs to their fully translocated positions. Subsequent engagement of peptidyl-tRNA and disengagement of deacyl-tRNA from mRNA, within their respective small subunit binding sites, facilitate the ribosome resetting mechanism after translocation has occurred to enable protein synthesis to resume.
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Affiliation(s)
- Wataru Nishima
- Theoretical Biology and Biophysics, Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
- New Mexico Consortium, Los Alamos, NM 87544, USA
| | - Dylan Girodat
- Theoretical Biology and Biophysics, Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
- New Mexico Consortium, Los Alamos, NM 87544, USA
| | - Mikael Holm
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Emily J Rundlet
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
- Tri-Institutional PhD Program in Chemical Biology, Weill Cornell Medicine, New York, NY 10021, USA
| | - Jose L Alejo
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN 55455, USA
| | - Kara Fischer
- New Mexico Consortium, Los Alamos, NM 87544, USA
| | - Scott C Blanchard
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Karissa Y Sanbonmatsu
- Theoretical Biology and Biophysics, Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
- New Mexico Consortium, Los Alamos, NM 87544, USA
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10
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Wieland M, Holm M, Rundlet EJ, Morici M, Koller TO, Maviza TP, Pogorevc D, Osterman IA, Müller R, Blanchard SC, Wilson DN. The cyclic octapeptide antibiotic argyrin B inhibits translation by trapping EF-G on the ribosome during translocation. Proc Natl Acad Sci U S A 2022; 119:e2114214119. [PMID: 35500116 PMCID: PMC9171646 DOI: 10.1073/pnas.2114214119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 03/16/2022] [Indexed: 11/18/2022] Open
Abstract
Argyrins are a family of naturally produced octapeptides that display promising antimicrobial activity against Pseudomonas aeruginosa. Argyrin B (ArgB) has been shown to interact with an elongated form of the translation elongation factor G (EF-G), leading to the suggestion that argyrins inhibit protein synthesis by interfering with EF-G binding to the ribosome. Here, using a combination of cryo-electron microscopy (cryo-EM) and single-molecule fluorescence resonance energy transfer (smFRET), we demonstrate that rather than interfering with ribosome binding, ArgB rapidly and specifically binds EF-G on the ribosome to inhibit intermediate steps of the translocation mechanism. Our data support that ArgB inhibits conformational changes within EF-G after GTP hydrolysis required for translocation and factor dissociation, analogous to the mechanism of fusidic acid, a chemically distinct antibiotic that binds a different region of EF-G. These findings shed light on the mechanism of action of the argyrin-class antibiotics on protein synthesis as well as the nature and importance of rate-limiting, intramolecular conformational events within the EF-G-bound ribosome during late-steps of translocation.
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Affiliation(s)
- Maximiliane Wieland
- Institute for Biochemistry and Molecular Biology, University of Hamburg, 20146 Hamburg, Germany
| | - Mikael Holm
- St. Jude Children's Research Hospital, Memphis, TN 38105
| | - Emily J. Rundlet
- St. Jude Children's Research Hospital, Memphis, TN 38105
- Weill Cornell Medicine, Tri-Institutional PhD Program in Chemical Biology, New York, NY 10065
| | - Martino Morici
- Institute for Biochemistry and Molecular Biology, University of Hamburg, 20146 Hamburg, Germany
| | - Timm O. Koller
- Institute for Biochemistry and Molecular Biology, University of Hamburg, 20146 Hamburg, Germany
| | - Tinashe P. Maviza
- Center of Life Sciences, Skolkovo Institute of Science and Technology, 121205 Moscow, Russia
| | - Domen Pogorevc
- Department Microbial Natural Products, Helmholtz Institute for Pharmaceutical Research Saarland, Helmholtz Centre for Infection Research, Saarland University, 66123 Saarbrücken,Germany
| | - Ilya A. Osterman
- Center of Life Sciences, Skolkovo Institute of Science and Technology, 121205 Moscow, Russia
- Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Rolf Müller
- Department Microbial Natural Products, Helmholtz Institute for Pharmaceutical Research Saarland, Helmholtz Centre for Infection Research, Saarland University, 66123 Saarbrücken,Germany
| | | | - Daniel N. Wilson
- Institute for Biochemistry and Molecular Biology, University of Hamburg, 20146 Hamburg, Germany
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11
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Seely SM, Gagnon MG. Mechanisms of ribosome recycling in bacteria and mitochondria: a structural perspective. RNA Biol 2022; 19:662-677. [PMID: 35485608 PMCID: PMC9067457 DOI: 10.1080/15476286.2022.2067712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Abstract
In all living cells, the ribosome translates the genetic information carried by messenger RNAs (mRNAs) into proteins. The process of ribosome recycling, a key step during protein synthesis that ensures ribosomal subunits remain available for new rounds of translation, has been largely overlooked. Despite being essential to the survival of the cell, several mechanistic aspects of ribosome recycling remain unclear. In eubacteria and mitochondria, recycling of the ribosome into subunits requires the concerted action of the ribosome recycling factor (RRF) and elongation factor G (EF-G). Recently, the conserved protein HflX was identified in bacteria as an alternative factor that recycles the ribosome under stress growth conditions. The homologue of HflX, the GTP-binding protein 6 (GTPBP6), has a dual role in mitochondrial translation by facilitating ribosome recycling and biogenesis. In this review, mechanisms of ribosome recycling in eubacteria and mitochondria are described based on structural studies of ribosome complexes.
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Affiliation(s)
- Savannah M Seely
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555-1019, USA
| | - Matthieu G Gagnon
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555-1019, USA.,Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555-1019, USA.,Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX 77555-1019, USA.,Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas 77555, USA
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12
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Cimicata G, Fridkin G, Bose T, Eyal Z, Halfon Y, Breiner-Goldstein E, Fox T, Zimmerman E, Bashan A, de Val N, Wlodawer A, Yonath A. Structural Studies Reveal the Role of Helix 68 in the Elongation Step of Protein Biosynthesis. mBio 2022; 13:e0030622. [PMID: 35348349 PMCID: PMC9040758 DOI: 10.1128/mbio.00306-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Accepted: 02/14/2022] [Indexed: 02/04/2023] Open
Abstract
The ribosome, a multicomponent assembly consisting of RNA and proteins, is a pivotal macromolecular machine that translates the genetic code into proteins. The large ribosomal subunit rRNA helix 68 (H68) is a key element in the protein synthesis process, as it coordinates the coupled movements of the actors involved in translocation, including the tRNAs and L1 stalk. Examination of cryo-electron microscopy (cryo-EM) structures of ribosomes incubated for various time durations at physiological temperatures led to the identification of functionally relevant H68 movements. These movements assist the transition of the L1 stalk between its open and closed states. H68 spatial flexibility and its significance to the protein synthesis process were confirmed through its effective targeting with antisense PNA oligomers. Our results suggest that H68 is actively involved in ribosome movements that are central to the elongation process. IMPORTANCE The mechanism that regulates the translocation step in ribosomes during protein synthesis is not fully understood. In this work, cryo-EM techniques used to image ribosomes from Staphylococcus aureus after incubation at physiological temperature allowed the identification of a conformation of the helix 68 that has never been observed so far. We then propose a mechanism in which such helix, switching between two different conformations, actively coordinates the translocation step, shedding light on the dynamics of ribosomal components. In addition, the relevance of helix 68 to ribosome function and its potential as an antibiotic target was proved by inhibiting Staphylococcus aureus ribosomes activity in vitro using oligomers with sequence complementarity.
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Affiliation(s)
- Giuseppe Cimicata
- Department of Chemical and Structural Biology, The Weizmann Institute of Science, Rehovot, Israel
| | - Gil Fridkin
- Department of Chemical and Structural Biology, The Weizmann Institute of Science, Rehovot, Israel
- Department of Organic Chemistry, Israel Institute for Biological Research, Ness Ziona, Israel
| | - Tanaya Bose
- Department of Chemical and Structural Biology, The Weizmann Institute of Science, Rehovot, Israel
| | - Zohar Eyal
- Department of Chemical and Structural Biology, The Weizmann Institute of Science, Rehovot, Israel
| | - Yehuda Halfon
- Department of Chemical and Structural Biology, The Weizmann Institute of Science, Rehovot, Israel
| | - Elinor Breiner-Goldstein
- Department of Chemical and Structural Biology, The Weizmann Institute of Science, Rehovot, Israel
| | - Tara Fox
- Center for Molecular Microscopy, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, Maryland, USA
| | - Ella Zimmerman
- Department of Chemical and Structural Biology, The Weizmann Institute of Science, Rehovot, Israel
| | - Anat Bashan
- Department of Chemical and Structural Biology, The Weizmann Institute of Science, Rehovot, Israel
| | - Natalia de Val
- Center for Molecular Microscopy, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, Maryland, USA
| | - Alexander Wlodawer
- Center for Structural Biology, Center for Cancer Research, National Cancer Institute, Frederick, Maryland, USA
| | - Ada Yonath
- Department of Chemical and Structural Biology, The Weizmann Institute of Science, Rehovot, Israel
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13
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Tirumalai MR, Rivas M, Tran Q, Fox GE. The Peptidyl Transferase Center: a Window to the Past. Microbiol Mol Biol Rev 2021; 85:e0010421. [PMID: 34756086 PMCID: PMC8579967 DOI: 10.1128/mmbr.00104-21] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
In his 2001 article, "Translation: in retrospect and prospect," the late Carl Woese made a prescient observation that there was a need for the then-current view of translation to be "reformulated to become an all-embracing perspective about which 21st century Biology can develop" (RNA 7:1055-1067, 2001, https://doi.org/10.1017/s1355838201010615). The quest to decipher the origins of life and the road to the genetic code are both inextricably linked with the history of the ribosome. After over 60 years of research, significant progress in our understanding of how ribosomes work has been made. Particularly attractive is a model in which the ribosome may facilitate an ∼180° rotation of the CCA end of the tRNA from the A-site to the P-site while the acceptor stem of the tRNA would then undergo a translation from the A-site to the P-site. However, the central question of how the ribosome originated remains unresolved. Along the path from a primitive RNA world or an RNA-peptide world to a proto-ribosome world, the advent of the peptidyl transferase activity would have been a seminal event. This functionality is now housed within a local region of the large-subunit (LSU) rRNA, namely, the peptidyl transferase center (PTC). The PTC is responsible for peptide bond formation during protein synthesis and is usually considered to be the oldest part of the modern ribosome. What is frequently overlooked is that by examining the origins of the PTC itself, one is likely going back even further in time. In this regard, it has been proposed that the modern PTC originated from the association of two smaller RNAs that were once independent and now comprise a pseudosymmetric region in the modern PTC. Could such an association have survived? Recent studies have shown that the extant PTC is largely depleted of ribosomal protein interactions. It is other elements like metallic ion coordination and nonstandard base/base interactions that would have had to stabilize the association of RNAs. Here, we present a detailed review of the literature focused on the nature of the extant PTC and its proposed ancestor, the proto-ribosome.
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Affiliation(s)
- Madhan R. Tirumalai
- Department of Biology and Biochemistry, University of Houston, Houston, Texas, USA
| | - Mario Rivas
- Department of Biology and Biochemistry, University of Houston, Houston, Texas, USA
| | - Quyen Tran
- Department of Biology and Biochemistry, University of Houston, Houston, Texas, USA
| | - George E. Fox
- Department of Biology and Biochemistry, University of Houston, Houston, Texas, USA
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14
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Datta M, Singh J, Modak MJ, Pillai M, Varshney U. Systematic evolution of initiation factor 3 and the ribosomal protein uS12 optimizes Escherichia coli growth with an unconventional initiator tRNA. Mol Microbiol 2021; 117:462-479. [PMID: 34889476 DOI: 10.1111/mmi.14861] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Revised: 12/07/2021] [Accepted: 12/07/2021] [Indexed: 11/28/2022]
Abstract
The anticodon stem of initiator tRNA (i-tRNA) possesses the characteristic three consecutive GC base pairs (G29:C41, G30:C40, and G31:C39 abbreviated as GC/GC/GC or 3GC pairs) crucial to commencing translation. To understand the importance of this highly conserved element, we isolated two fast-growing suppressors of Escherichia coli sustained solely on an unconventional i-tRNA (i-tRNAcg/GC/cg ) having cg/GC/cg sequence instead of the conventional GC/GC/GC. Both suppressors have the common mutation of V93A in initiation factor 3 (IF3), and additional mutations of either V32L (Sup-1) or H76L (Sup-2) in small subunit ribosomal protein 12 (uS12). The V93A mutation in IF3 was necessary for relaxed fidelity of i-tRNA selection to sustain on i-tRNAcg/GC/cg though with a retarded growth. Subsequent mutations in uS12 salvaged the retarded growth by enhancing the fidelity of translation. The H76L mutation in uS12 showed better fidelity of i-tRNA selection. However, the V32L mutation compensated for the deficient fidelity of i-tRNA selection by ensuring an efficient fidelity check by ribosome recycling factor (RRF). We reveal unique genetic networks between uS12, IF3 and i-tRNA in initiation and between uS12, elongation factor-G (EF-G), RRF, and Pth (peptidyl-tRNA hydrolase) which, taken together, govern the fidelity of translation in bacteria.
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Affiliation(s)
- Madhurima Datta
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
| | - Jitendra Singh
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
| | - Mamata Jayant Modak
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
| | - Maalavika Pillai
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
| | - Umesh Varshney
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India.,Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, India
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15
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Petrychenko V, Peng BZ, de A P Schwarzer AC, Peske F, Rodnina MV, Fischer N. Structural mechanism of GTPase-powered ribosome-tRNA movement. Nat Commun 2021; 12:5933. [PMID: 34635670 PMCID: PMC8505512 DOI: 10.1038/s41467-021-26133-x] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 09/17/2021] [Indexed: 11/25/2022] Open
Abstract
GTPases are regulators of cell signaling acting as molecular switches. The translational GTPase EF-G stands out, as it uses GTP hydrolysis to generate force and promote the movement of the ribosome along the mRNA. The key unresolved question is how GTP hydrolysis drives molecular movement. Here, we visualize the GTPase-powered step of ongoing translocation by time-resolved cryo-EM. EF-G in the active GDP-Pi form stabilizes the rotated conformation of ribosomal subunits and induces twisting of the sarcin-ricin loop of the 23 S rRNA. Refolding of the GTPase switch regions upon Pi release initiates a large-scale rigid-body rotation of EF-G pivoting around the sarcin-ricin loop that facilitates back rotation of the ribosomal subunits and forward swiveling of the head domain of the small subunit, ultimately driving tRNA forward movement. The findings demonstrate how a GTPase orchestrates spontaneous thermal fluctuations of a large RNA-protein complex into force-generating molecular movement.
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MESH Headings
- Binding Sites
- Biomechanical Phenomena
- Cryoelectron Microscopy
- Escherichia coli/genetics
- Escherichia coli/metabolism
- Guanosine Triphosphate/chemistry
- Guanosine Triphosphate/metabolism
- Hydrolysis
- Kinetics
- Models, Molecular
- Peptide Elongation Factor G/chemistry
- Peptide Elongation Factor G/genetics
- Peptide Elongation Factor G/metabolism
- Protein Binding
- Protein Biosynthesis
- Protein Conformation, alpha-Helical
- Protein Conformation, beta-Strand
- Protein Folding
- Protein Interaction Domains and Motifs
- RNA, Messenger/chemistry
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- RNA, Ribosomal, 23S/chemistry
- RNA, Ribosomal, 23S/genetics
- RNA, Ribosomal, 23S/metabolism
- RNA, Transfer/chemistry
- RNA, Transfer/genetics
- RNA, Transfer/metabolism
- Ribosomes/metabolism
- Ribosomes/ultrastructure
- Thermodynamics
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Affiliation(s)
- Valentyn Petrychenko
- Department of Structural Dynamics, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Bee-Zen Peng
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Ana C de A P Schwarzer
- Department of Structural Dynamics, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
- Department of Molecular Biology, University Medical Center Göttingen, Göttingen, Germany
| | - Frank Peske
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Marina V Rodnina
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.
| | - Niels Fischer
- Department of Structural Dynamics, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.
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16
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Demo G, Gamper HB, Loveland AB, Masuda I, Carbone CE, Svidritskiy E, Hou YM, Korostelev AA. Structural basis for +1 ribosomal frameshifting during EF-G-catalyzed translocation. Nat Commun 2021; 12:4644. [PMID: 34330903 PMCID: PMC8324841 DOI: 10.1038/s41467-021-24911-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 07/12/2021] [Indexed: 12/25/2022] Open
Abstract
Frameshifting of mRNA during translation provides a strategy to expand the coding repertoire of cells and viruses. How and where in the elongation cycle +1-frameshifting occurs remains poorly understood. We describe seven ~3.5-Å-resolution cryo-EM structures of 70S ribosome complexes, allowing visualization of elongation and translocation by the GTPase elongation factor G (EF-G). Four structures with a + 1-frameshifting-prone mRNA reveal that frameshifting takes place during translocation of tRNA and mRNA. Prior to EF-G binding, the pre-translocation complex features an in-frame tRNA-mRNA pairing in the A site. In the partially translocated structure with EF-G•GDPCP, the tRNA shifts to the +1-frame near the P site, rendering the freed mRNA base to bulge between the P and E sites and to stack on the 16S rRNA nucleotide G926. The ribosome remains frameshifted in the nearly post-translocation state. Our findings demonstrate that the ribosome and EF-G cooperate to induce +1 frameshifting during tRNA-mRNA translocation.
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MESH Headings
- Biocatalysis
- Cryoelectron Microscopy
- Escherichia coli/genetics
- Escherichia coli/metabolism
- Escherichia coli Proteins/chemistry
- Escherichia coli Proteins/genetics
- Escherichia coli Proteins/metabolism
- Frameshifting, Ribosomal/genetics
- Models, Molecular
- Nucleic Acid Conformation
- Peptide Chain Elongation, Translational/genetics
- Peptide Elongation Factor G/chemistry
- Peptide Elongation Factor G/genetics
- Peptide Elongation Factor G/metabolism
- Protein Conformation
- RNA, Messenger/chemistry
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- RNA, Ribosomal, 16S/chemistry
- RNA, Ribosomal, 16S/genetics
- RNA, Ribosomal, 16S/metabolism
- RNA, Transfer/chemistry
- RNA, Transfer/genetics
- RNA, Transfer/metabolism
- Ribosomes/genetics
- Ribosomes/metabolism
- Ribosomes/ultrastructure
- tRNA Methyltransferases/genetics
- tRNA Methyltransferases/metabolism
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Affiliation(s)
- Gabriel Demo
- RNA Therapeutics Institute, Department of Biochemistry and Molecular Pharmacology, UMass Medical School, Worcester, MA, USA
- Central European Institute of Technology, Masaryk University, Brno, Czech Republic
| | - Howard B Gamper
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Anna B Loveland
- RNA Therapeutics Institute, Department of Biochemistry and Molecular Pharmacology, UMass Medical School, Worcester, MA, USA
| | - Isao Masuda
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Christine E Carbone
- RNA Therapeutics Institute, Department of Biochemistry and Molecular Pharmacology, UMass Medical School, Worcester, MA, USA
| | - Egor Svidritskiy
- RNA Therapeutics Institute, Department of Biochemistry and Molecular Pharmacology, UMass Medical School, Worcester, MA, USA
| | - Ya-Ming Hou
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA, USA.
| | - Andrei A Korostelev
- RNA Therapeutics Institute, Department of Biochemistry and Molecular Pharmacology, UMass Medical School, Worcester, MA, USA.
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17
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Paleskava A, Kaiumov MY, Kirillov SV, Konevega AL. Peculiarities in Activation of Hydrolytic Activity of Elongation Factors. BIOCHEMISTRY (MOSCOW) 2021; 85:1422-1433. [PMID: 33280582 DOI: 10.1134/s0006297920110103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Translational GTPases (trGTPases) belong to the family of G proteins and play key roles at all stages of protein biosynthesis on the ribosome. Unidirectional and cyclic functioning of G proteins is ensured by their ability to switch between the active and inactive states due to GTP hydrolysis accelerated by the auxiliary GTPase-activating proteins. Although trGTPases interact with the ribosomes in different conformational states, they bind to the same conserved region, which, unlike in classical GTPase-activating proteins, is represented by ribosomal RNA. The resulting catalytic sites have almost identical structure in all elongation factors suggesting a common mechanism of GTP hydrolysis. However, fine details of the activated state formation and significantly different rates of GTP hydrolysis indicate the existence of distinctive features upon GTP hydrolysis catalyzed by the different factors. Here, we present a contemporary view on the mechanism of GTPase activation and GTP hydrolysis by the elongation factors EF-Tu, EF-G, and SelB based on the analysis of structural, biochemical, and bioinformatics data.
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Affiliation(s)
- A Paleskava
- Petersburg Nuclear Physics Institute named by B.P. Konstantinov of NRC "Kurchatov Institute", Gatchina, Leningrad Region, 188300, Russia
| | - M Yu Kaiumov
- Petersburg Nuclear Physics Institute named by B.P. Konstantinov of NRC "Kurchatov Institute", Gatchina, Leningrad Region, 188300, Russia
| | - S V Kirillov
- Petersburg Nuclear Physics Institute named by B.P. Konstantinov of NRC "Kurchatov Institute", Gatchina, Leningrad Region, 188300, Russia
| | - A L Konevega
- Petersburg Nuclear Physics Institute named by B.P. Konstantinov of NRC "Kurchatov Institute", Gatchina, Leningrad Region, 188300, Russia.
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18
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Koripella RK, Deep A, Agrawal EK, Keshavan P, Banavali NK, Agrawal RK. Distinct mechanisms of the human mitoribosome recycling and antibiotic resistance. Nat Commun 2021; 12:3607. [PMID: 34127662 PMCID: PMC8203779 DOI: 10.1038/s41467-021-23726-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 05/14/2021] [Indexed: 11/16/2022] Open
Abstract
Ribosomes are recycled for a new round of translation initiation by dissociation of ribosomal subunits, messenger RNA and transfer RNA from their translational post-termination complex. Here we present cryo-EM structures of the human 55S mitochondrial ribosome (mitoribosome) and the mitoribosomal large 39S subunit in complex with mitoribosome recycling factor (RRFmt) and a recycling-specific homolog of elongation factor G (EF-G2mt). These structures clarify an unusual role of a mitochondria-specific segment of RRFmt, identify the structural distinctions that confer functional specificity to EF-G2mt, and show that the deacylated tRNA remains with the dissociated 39S subunit, suggesting a distinct sequence of events in mitoribosome recycling. Furthermore, biochemical and structural analyses reveal that the molecular mechanism of antibiotic fusidic acid resistance for EF-G2mt is markedly different from that of mitochondrial elongation factor EF-G1mt, suggesting that the two human EF-Gmts have evolved diversely to negate the effect of a bacterial antibiotic. High-resolution cryo-EM structures and biochemical analyses of the human mitoribosome, in complex with mitochondria-specific factors mediating mitoribosome recycling, RRFmt and EF-G2mt, offer insight into mechanisms of mitoribosome recycling and resistance to antibiotic fusidic acid.
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Affiliation(s)
- Ravi Kiran Koripella
- Division of Translational Medicine, Wadsworth Center, New York State Department of Health, Empire State Plaza, Albany, NY, USA
| | - Ayush Deep
- Division of Translational Medicine, Wadsworth Center, New York State Department of Health, Empire State Plaza, Albany, NY, USA
| | - Ekansh K Agrawal
- Division of Translational Medicine, Wadsworth Center, New York State Department of Health, Empire State Plaza, Albany, NY, USA
| | - Pooja Keshavan
- Division of Translational Medicine, Wadsworth Center, New York State Department of Health, Empire State Plaza, Albany, NY, USA
| | - Nilesh K Banavali
- Division of Translational Medicine, Wadsworth Center, New York State Department of Health, Empire State Plaza, Albany, NY, USA.,Department of Biomedical Sciences, University at Albany, Albany, NY, USA
| | - Rajendra K Agrawal
- Division of Translational Medicine, Wadsworth Center, New York State Department of Health, Empire State Plaza, Albany, NY, USA. .,Department of Biomedical Sciences, University at Albany, Albany, NY, USA.
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19
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Maksimova EM, Vinogradova DS, Osterman IA, Kasatsky PS, Nikonov OS, Milón P, Dontsova OA, Sergiev PV, Paleskava A, Konevega AL. Multifaceted Mechanism of Amicoumacin A Inhibition of Bacterial Translation. Front Microbiol 2021; 12:618857. [PMID: 33643246 PMCID: PMC7907450 DOI: 10.3389/fmicb.2021.618857] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Accepted: 01/19/2021] [Indexed: 01/07/2023] Open
Abstract
Amicoumacin A (Ami) halts bacterial growth by inhibiting the ribosome during translation. The Ami binding site locates in the vicinity of the E-site codon of mRNA. However, Ami does not clash with mRNA, rather stabilizes it, which is relatively unusual and implies a unique way of translation inhibition. In this work, we performed a kinetic and thermodynamic investigation of Ami influence on the main steps of polypeptide synthesis. We show that Ami reduces the rate of the functional canonical 70S initiation complex (IC) formation by 30-fold. Additionally, our results indicate that Ami promotes the formation of erroneous 30S ICs; however, IF3 prevents them from progressing towards translation initiation. During early elongation steps, Ami does not compromise EF-Tu-dependent A-site binding or peptide bond formation. On the other hand, Ami reduces the rate of peptidyl-tRNA movement from the A to the P site and significantly decreases the amount of the ribosomes capable of polypeptide synthesis. Our data indicate that Ami progressively decreases the activity of translating ribosomes that may appear to be the main inhibitory mechanism of Ami. Indeed, the use of EF-G mutants that confer resistance to Ami (G542V, G581A, or ins544V) leads to a complete restoration of the ribosome functionality. It is possible that the changes in translocation induced by EF-G mutants compensate for the activity loss caused by Ami.
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Affiliation(s)
- Elena M Maksimova
- Petersburg Nuclear Physics Institute named by B. P. Konstantinov, NRC "Kurchatov Institute", Gatchina, Russia
| | - Daria S Vinogradova
- Petersburg Nuclear Physics Institute named by B. P. Konstantinov, NRC "Kurchatov Institute", Gatchina, Russia.,NanoTemper Technologies Rus, St. Petersburg, Russia
| | - Ilya A Osterman
- Center of Life Sciences, Skolkovo Institute of Science and Technology, Moscow, Russia.,Department of Chemistry, Lomonosov Moscow State University, Moscow, Russia
| | - Pavel S Kasatsky
- Petersburg Nuclear Physics Institute named by B. P. Konstantinov, NRC "Kurchatov Institute", Gatchina, Russia
| | - Oleg S Nikonov
- Institute of Protein Research, Russian Academy of Sciences, Pushchino, Russia
| | - Pohl Milón
- Centre for Research and Innovation, Faculty of Health Sciences, Universidad Peruana de Ciencias Aplicadas (UPC), Lima, Peru
| | - Olga A Dontsova
- Center of Life Sciences, Skolkovo Institute of Science and Technology, Moscow, Russia.,Department of Chemistry, Lomonosov Moscow State University, Moscow, Russia.,A. N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia.,Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, Russia
| | - Petr V Sergiev
- Center of Life Sciences, Skolkovo Institute of Science and Technology, Moscow, Russia.,Department of Chemistry, Lomonosov Moscow State University, Moscow, Russia.,A. N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia.,Institute of Functional Genomics, Lomonosov Moscow State University, Moscow, Russia
| | - Alena Paleskava
- Petersburg Nuclear Physics Institute named by B. P. Konstantinov, NRC "Kurchatov Institute", Gatchina, Russia
| | - Andrey L Konevega
- Petersburg Nuclear Physics Institute named by B. P. Konstantinov, NRC "Kurchatov Institute", Gatchina, Russia.,National Research Centre "Kurchatov Institute", Moscow, Russia
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20
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Nikolay R, Hilal T, Schmidt S, Qin B, Schwefel D, Vieira-Vieira CH, Mielke T, Bürger J, Loerke J, Amikura K, Flügel T, Ueda T, Selbach M, Deuerling E, Spahn CMT. Snapshots of native pre-50S ribosomes reveal a biogenesis factor network and evolutionary specialization. Mol Cell 2021; 81:1200-1215.e9. [PMID: 33639093 DOI: 10.1016/j.molcel.2021.02.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 11/11/2020] [Accepted: 02/02/2021] [Indexed: 01/13/2023]
Abstract
Ribosome biogenesis is a fundamental multi-step cellular process that culminates in the formation of ribosomal subunits, whose production and modification are regulated by numerous biogenesis factors. In this study, we analyze physiologic prokaryotic ribosome biogenesis by isolating bona fide pre-50S subunits from an Escherichia coli strain with the biogenesis factor ObgE, affinity tagged at its native gene locus. Our integrative structural approach reveals a network of interacting biogenesis factors consisting of YjgA, RluD, RsfS, and ObgE on the immature pre-50S subunit. In addition, our study provides mechanistic insight into how the GTPase ObgE, in concert with other biogenesis factors, facilitates the maturation of the 50S functional core and reveals both conserved and divergent evolutionary features of ribosome biogenesis between prokaryotes and eukaryotes.
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Affiliation(s)
- Rainer Nikolay
- Institut für Medizinische Physik und Biophysik, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany.
| | - Tarek Hilal
- Institut für Medizinische Physik und Biophysik, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany; Freie Universität Berlin, Research Centre for Electron Microscopy, Fabeckstr. 36a, 14195 Berlin, Germany
| | - Sabine Schmidt
- Molekulare Mikrobiologie, Universität Konstanz, Konstanz, Germany
| | - Bo Qin
- Institut für Medizinische Physik und Biophysik, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - David Schwefel
- Institut für Medizinische Physik und Biophysik, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Carlos H Vieira-Vieira
- Proteome Dynamics, Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Robert-Rössle-Str. 10, 13125 Berlin, Germany; Faculty of Life Sciences, Humboldt Universität zu Berlin, Berlin, Germany
| | - Thorsten Mielke
- Microscopy and Cryo-Electron Microscopy Service Group, Max Planck Institute for Molecular Genetics, Ihnestr. 63-73, 14195 Berlin, Germany
| | - Jörg Bürger
- Institut für Medizinische Physik und Biophysik, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany; Microscopy and Cryo-Electron Microscopy Service Group, Max Planck Institute for Molecular Genetics, Ihnestr. 63-73, 14195 Berlin, Germany
| | - Justus Loerke
- Institut für Medizinische Physik und Biophysik, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Kazuaki Amikura
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, FSB-401, 5-1-5, Kashiwanoha, Kashiwa, Chiba 277-8562, Japan
| | - Timo Flügel
- Institut für Medizinische Physik und Biophysik, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Takuya Ueda
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, FSB-401, 5-1-5, Kashiwanoha, Kashiwa, Chiba 277-8562, Japan
| | - Matthias Selbach
- Proteome Dynamics, Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Robert-Rössle-Str. 10, 13125 Berlin, Germany; Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany
| | - Elke Deuerling
- Molekulare Mikrobiologie, Universität Konstanz, Konstanz, Germany
| | - Christian M T Spahn
- Institut für Medizinische Physik und Biophysik, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany.
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21
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Datta M, Pillai M, Modak MJ, Liiv A, Khaja FT, Hussain T, Remme J, Varshney U. A mutation in the ribosomal protein uS12 reveals novel functions of its universally conserved PNSA loop. Mol Microbiol 2021; 115:1292-1308. [PMID: 33368752 DOI: 10.1111/mmi.14675] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2020] [Revised: 12/18/2020] [Accepted: 12/19/2020] [Indexed: 11/28/2022]
Abstract
The ribosomal protein uS12 is conserved across all domains of life. Recently, a heterozygous spontaneous mutation in human uS12 (corresponding to R49K mutation immediately downstream of the universally conserved 44 PNSA47 loop in Escherichia coli uS12) was identified for causing ribosomopathy, highlighting the importance of the PNSA loop. To investigate the effects of a similar mutation in the absence of any wild-type alleles, we mutated the rpsL gene (encoding uS12) in E. coli. Consistent with its pathology (in humans), we were unable to generate the R49K mutation in E. coli in the absence of a support plasmid. However, we were able to generate the L48K mutation in its immediate vicinity. The L48K mutation resulted in a cold sensitive phenotype and ribosome biogenesis defect in the strain. We show that the L48K mutation impacts the steps of initiation and elongation. Furthermore, the genetic interactions of the L48K mutation with RRF and Pth suggest a novel role of the PNSA loop in ribosome recycling. Our studies reveal new functions of the PNSA loop in uS12, which has so far been studied in the context of translation elongation.
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Affiliation(s)
- Madhurima Datta
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
| | - Maalavika Pillai
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
| | - Mamata Jayant Modak
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
| | - Aivar Liiv
- Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia
| | - Faisal Tarique Khaja
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bangalore, India
| | - Tanweer Hussain
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bangalore, India
| | - Jaanus Remme
- Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia
| | - Umesh Varshney
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India.,Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, India
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22
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Vila-Sanjurjo A, Smith PM, Elson JL. Heterologous Inferential Analysis (HIA) and Other Emerging Concepts: In Understanding Mitochondrial Variation In Pathogenesis: There is no More Low-Hanging Fruit. Methods Mol Biol 2021; 2277:203-245. [PMID: 34080154 DOI: 10.1007/978-1-0716-1270-5_14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Here we summarize our latest efforts to elucidate the role of mtDNA variants affecting the mitochondrial translation machinery, namely variants mapping to the mt-rRNA and mt-tRNA genes. Evidence is accumulating to suggest that the cellular response to interference with mitochondrial translation is different from that occurring as a result of mutations in genes encoding OXPHOS proteins. As a result, it appears safe to state that a complete view of mitochondrial disease will not be obtained until we understand the effect of mt-rRNA and mt-tRNA variants on mitochondrial protein synthesis. Despite the identification of a large number of potentially pathogenic variants in the mitochondrially encoded rRNA (mt-rRNA) genes, we lack direct methods to firmly establish their pathogenicity. In the absence of such methods, we have devised an indirect approach named heterologous inferential analysis (HIA ) that can be used to make predictions concerning the disruptive potential of a large subset of mt-rRNA variants. We have used HIA to explore the mutational landscape of 12S and 16S mt-rRNA genes. Our HIA studies include a thorough classification of all rare variants reported in the literature as well as others obtained from studies performed in collaboration with physicians. HIA has also been used with non-mammalian mt-rRNA genes to elucidate how mitotypes influence the interaction of the individual and the environment. Regarding mt-tRNA variations, rapidly growing evidence shows that the spectrum of mutations causing mitochondrial disease might differ between the different mitochondrial haplogroups seen in human populations.
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Affiliation(s)
- Antón Vila-Sanjurjo
- Departamento de Bioloxía, Facultade de Ciencias, Centro de Investigacións en Ciencias Avanzadas (CICA), Universidade da Coruña, A Coruña, Spain.
| | - Paul M Smith
- Department of Paediatrics, Royal Aberdeen Children's Hospital, Aberdeen, UK
| | - Joanna L Elson
- Biosciences Institute Newcastle, Newcastle University, Newcastle upon Tyne, UK.
- Human Metabolomics, North-West University, Potchefstroom, South Africa.
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23
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Abstract
Peptide-chain elongation during protein synthesis entails sequential aminoacyl-tRNA selection and translocation reactions that proceed rapidly (2-20 per second) and with a low error rate (around 10-3 to 10-5 at each step) over thousands of cycles1. The cadence and fidelity of ribosome transit through mRNA templates in discrete codon increments is a paradigm for movement in biological systems that must hold for diverse mRNA and tRNA substrates across domains of life. Here we use single-molecule fluorescence methods to guide the capture of structures of early translocation events on the bacterial ribosome. Our findings reveal that the bacterial GTPase elongation factor G specifically engages spontaneously achieved ribosome conformations while in an active, GTP-bound conformation to unlock and initiate peptidyl-tRNA translocation. These findings suggest that processes intrinsic to the pre-translocation ribosome complex can regulate the rate of protein synthesis, and that energy expenditure is used later in the translocation mechanism than previously proposed.
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24
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Calvet LE, Matviienko S, Ducluzaux P. Network theory of the bacterial ribosome. PLoS One 2020; 15:e0239700. [PMID: 33017414 PMCID: PMC7535068 DOI: 10.1371/journal.pone.0239700] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 09/08/2020] [Indexed: 02/07/2023] Open
Abstract
In the past two decades, research into the biochemical, biophysical and structural properties of the ribosome have revealed many different steps of protein translation. Nevertheless, a complete understanding of how they lead to a rapid and accurate protein synthesis still remains a challenge. Here we consider a coarse network analysis in the bacterial ribosome formed by the connectivity between ribosomal (r) proteins and RNAs at different stages in the elongation cycle. The ribosomal networks are found to be dis-assortative and small world, implying that the structure allows for an efficient exchange of information between distant locations. An analysis of centrality shows that the second and fifth domains of 23S rRNA are the most important elements in all of the networks. Ribosomal protein hubs connect to much fewer nodes but are shown to provide important connectivity within the network (high closeness centrality). A modularity analysis reveals some of the different functional communities, indicating some known and some new possible communication pathways Our mathematical results confirm important communication pathways that have been discussed in previous research, thus verifying the use of this technique for representing the ribosome, and also reveal new insights into the collective function of ribosomal elements.
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Affiliation(s)
- Laurie E. Calvet
- CNRS, Centre de Nanosciences et Nanotechnologies, Université Paris-Saclay, Palaiseau, France
- * E-mail:
| | - Serhii Matviienko
- CNRS, Centre de Nanosciences et Nanotechnologies, Université Paris-Saclay, Palaiseau, France
| | - Pierre Ducluzaux
- CNRS, Centre de Nanosciences et Nanotechnologies, Université Paris-Saclay, Palaiseau, France
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25
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Simms CL, Yan LL, Qiu JK, Zaher HS. Ribosome Collisions Result in +1 Frameshifting in the Absence of No-Go Decay. Cell Rep 2020; 28:1679-1689.e4. [PMID: 31412239 PMCID: PMC6701860 DOI: 10.1016/j.celrep.2019.07.046] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Revised: 06/17/2019] [Accepted: 07/15/2019] [Indexed: 12/22/2022] Open
Abstract
During translation, an mRNA is typically occupied by multiple ribosomes sparsely distributed across the coding sequence. This distribution, mediated by slow rates of initiation relative to elongation, ensures that they rarely collide with each other, but given the stochastic nature of protein synthesis, collision events do occur. Recent work from our lab suggested that collisions signal for mRNA degradation through no-go decay (NGD). We have explored the impact of stalling on ribosome function when NGD is compromised and found it to result in +1 frameshifting. We used reporters that limit the number of ribosomes on a transcript to show that +1 frameshifting is induced through ribosome collision in yeast and bacteria. Furthermore, we observe a positive correlation between ribosome density and frameshifting efficiency. It is thus tempting to speculate that NGD, in addition to its role in mRNA quality control, evolved to cope with stochastic collision events to prevent deleterious frameshifting events. Ribosome collisions, resulting from stalling, activate quality control processes to degrade the aberrant mRNA and the incomplete peptide. mRNA degradation proceeds through an endonucleolytic cleavage between the stacked ribosomes, which resolves the collisions. Simms et al. show that, when cleavage is inhibited, colliding ribosomes move out of frame.
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Affiliation(s)
- Carrie L Simms
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Liewei L Yan
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Jessica K Qiu
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Hani S Zaher
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63130, USA.
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26
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Rodnina MV, Peske F, Peng BZ, Belardinelli R, Wintermeyer W. Converting GTP hydrolysis into motion: versatile translational elongation factor G. Biol Chem 2020; 401:131-142. [PMID: 31600135 DOI: 10.1515/hsz-2019-0313] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Accepted: 08/24/2019] [Indexed: 12/16/2022]
Abstract
Elongation factor G (EF-G) is a translational GTPase that acts at several stages of protein synthesis. Its canonical function is to catalyze tRNA movement during translation elongation, but it also acts at the last step of translation to promote ribosome recycling. Moreover, EF-G has additional functions, such as helping the ribosome to maintain the mRNA reading frame or to slide over non-coding stretches of the mRNA. EF-G has an unconventional GTPase cycle that couples the energy of GTP hydrolysis to movement. EF-G facilitates movement in the GDP-Pi form. To convert the energy of hydrolysis to movement, it requires various ligands in the A site, such as a tRNA in translocation, an mRNA secondary structure element in ribosome sliding, or ribosome recycling factor in post-termination complex disassembly. The ligand defines the direction and timing of EF-G-facilitated motion. In this review, we summarize recent advances in understanding the mechanism of EF-G action as a remarkable force-generating GTPase.
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Affiliation(s)
- Marina V Rodnina
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, D-37077 Göttingen, Germany
| | - Frank Peske
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, D-37077 Göttingen, Germany
| | - Bee-Zen Peng
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, D-37077 Göttingen, Germany
| | - Riccardo Belardinelli
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, D-37077 Göttingen, Germany
| | - Wolfgang Wintermeyer
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, D-37077 Göttingen, Germany
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27
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Kummer E, Ban N. Structural insights into mammalian mitochondrial translation elongation catalyzed by mtEFG1. EMBO J 2020; 39:e104820. [PMID: 32602580 PMCID: PMC7396830 DOI: 10.15252/embj.2020104820] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 05/08/2020] [Accepted: 05/11/2020] [Indexed: 01/08/2023] Open
Abstract
Mitochondria are eukaryotic organelles of bacterial origin where respiration takes place to produce cellular chemical energy. These reactions are catalyzed by the respiratory chain complexes located in the inner mitochondrial membrane. Notably, key components of the respiratory chain complexes are encoded on the mitochondrial chromosome and their expression relies on a dedicated mitochondrial translation machinery. Defects in the mitochondrial gene expression machinery lead to a variety of diseases in humans mostly affecting tissues with high energy demand such as the nervous system, the heart, or the muscles. The mitochondrial translation system has substantially diverged from its bacterial ancestor, including alterations in the mitoribosomal architecture, multiple changes to the set of translation factors and striking reductions in otherwise conserved tRNA elements. Although a number of structures of mitochondrial ribosomes from different species have been determined, our mechanistic understanding of the mitochondrial translation cycle remains largely unexplored. Here, we present two cryo-EM reconstructions of human mitochondrial elongation factor G1 bound to the mammalian mitochondrial ribosome at two different steps of the tRNA translocation reaction during translation elongation. Our structures explain the mechanism of tRNA and mRNA translocation on the mitoribosome, the regulation of mtEFG1 activity by the ribosomal GTPase-associated center, and the basis of decreased susceptibility of mtEFG1 to the commonly used antibiotic fusidic acid.
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Affiliation(s)
- Eva Kummer
- Department of BiologyInstitute of Molecular Biology and BiophysicsSwiss Federal Institute of Technology ZurichZurichSwitzerland
| | - Nenad Ban
- Department of BiologyInstitute of Molecular Biology and BiophysicsSwiss Federal Institute of Technology ZurichZurichSwitzerland
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28
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Koripella RK, Sharma MR, Bhargava K, Datta PP, Kaushal PS, Keshavan P, Spremulli LL, Banavali NK, Agrawal RK. Structures of the human mitochondrial ribosome bound to EF-G1 reveal distinct features of mitochondrial translation elongation. Nat Commun 2020; 11:3830. [PMID: 32737313 PMCID: PMC7395135 DOI: 10.1038/s41467-020-17715-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Accepted: 07/15/2020] [Indexed: 02/06/2023] Open
Abstract
The mammalian mitochondrial ribosome (mitoribosome) and its associated translational factors have evolved to accommodate greater participation of proteins in mitochondrial translation. Here we present the 2.68-3.96 Å cryo-EM structures of the human 55S mitoribosome in complex with the human mitochondrial elongation factor G1 (EF-G1mt) in three distinct conformational states, including an intermediate state and a post-translocational state. These structures reveal the role of several mitochondria-specific (mito-specific) mitoribosomal proteins (MRPs) and a mito-specific segment of EF-G1mt in mitochondrial tRNA (tRNAmt) translocation. In particular, the mito-specific C-terminal extension in EF-G1mt is directly involved in translocation of the acceptor arm of the A-site tRNAmt. In addition to the ratchet-like and independent head-swiveling motions exhibited by the small mitoribosomal subunit, we discover significant conformational changes in MRP mL45 at the nascent polypeptide-exit site within the large mitoribosomal subunit that could be critical for tethering of the elongating mitoribosome onto the inner-mitochondrial membrane.
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MESH Headings
- Amino Acid Sequence
- Binding Sites
- Cryoelectron Microscopy
- HEK293 Cells
- Humans
- Mitochondria/metabolism
- Mitochondria/ultrastructure
- Mitochondrial Membranes/metabolism
- Mitochondrial Membranes/ultrastructure
- Mitochondrial Proteins/chemistry
- Mitochondrial Proteins/genetics
- Mitochondrial Proteins/metabolism
- Models, Molecular
- Nucleic Acid Conformation
- Peptide Chain Elongation, Translational
- Peptide Elongation Factor G/chemistry
- Peptide Elongation Factor G/genetics
- Peptide Elongation Factor G/metabolism
- Protein Binding
- Protein Conformation, alpha-Helical
- Protein Conformation, beta-Strand
- Protein Interaction Domains and Motifs
- RNA, Mitochondrial/chemistry
- RNA, Mitochondrial/genetics
- RNA, Mitochondrial/metabolism
- RNA, Transfer/chemistry
- RNA, Transfer/genetics
- RNA, Transfer/metabolism
- Recombinant Proteins/chemistry
- Recombinant Proteins/genetics
- Recombinant Proteins/metabolism
- Ribosomal Proteins/chemistry
- Ribosomal Proteins/genetics
- Ribosomal Proteins/metabolism
- Ribosomes/metabolism
- Ribosomes/ultrastructure
- Sequence Alignment
- Sequence Homology, Amino Acid
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Affiliation(s)
- Ravi Kiran Koripella
- Division of Translational Medicine, Wadsworth Center, New York State Department of Health, Empire State Plaza, Albany, NY, 12201, USA
| | - Manjuli R Sharma
- Division of Translational Medicine, Wadsworth Center, New York State Department of Health, Empire State Plaza, Albany, NY, 12201, USA
| | - Kalpana Bhargava
- Department of Chemistry, Campus Box 3290, University of North Carolina, Chapel Hill, NC, USA
- High Energy Material Research Lab, Defense Research and Development Organization, Sutarwadi, Pashan, Pune, Maharashtra, 411021, India
| | - Partha P Datta
- Division of Translational Medicine, Wadsworth Center, New York State Department of Health, Empire State Plaza, Albany, NY, 12201, USA
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, West Bengal, 741246, India
| | - Prem S Kaushal
- Division of Translational Medicine, Wadsworth Center, New York State Department of Health, Empire State Plaza, Albany, NY, 12201, USA
- Regional Centre for Biotechnology, 3rd Milestone, Faridabad-Gurgaon Expressway, PO Box # 3, Faridabad, Haryana, 121001, India
| | - Pooja Keshavan
- Division of Translational Medicine, Wadsworth Center, New York State Department of Health, Empire State Plaza, Albany, NY, 12201, USA
| | - Linda L Spremulli
- Department of Chemistry, Campus Box 3290, University of North Carolina, Chapel Hill, NC, USA
| | - Nilesh K Banavali
- Division of Translational Medicine, Wadsworth Center, New York State Department of Health, Empire State Plaza, Albany, NY, 12201, USA
- Department of Biomedical Sciences, University at Albany, SUNY, Albany, NY, 12201-0509, USA
| | - Rajendra K Agrawal
- Division of Translational Medicine, Wadsworth Center, New York State Department of Health, Empire State Plaza, Albany, NY, 12201, USA.
- Department of Biomedical Sciences, University at Albany, SUNY, Albany, NY, 12201-0509, USA.
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29
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Multiplexed genomic encoding of non-canonical amino acids for labeling large complexes. Nat Chem Biol 2020; 16:1129-1135. [PMID: 32690942 PMCID: PMC7982790 DOI: 10.1038/s41589-020-0599-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 06/23/2020] [Indexed: 12/21/2022]
Abstract
Stunning advances in the structural biology of multicomponent biomolecular complexes (MBCs) have ushered in an era of intense, structure-guided mechanistic and functional studies of these complexes. Nonetheless, existing methods to site-specifically conjugate MBCs with biochemical and biophysical labels are notoriously impracticable and/or significantly perturb MBC assembly and function. To overcome these limitations, we have developed a general, multiplexed method in which we genomically encode non-canonical amino acids (ncAAs) into multiple, structure-informed, individual sites within a target MBC; select for ncAA-containing MBC variants that assemble and function like the wildtype MBC; and site-specifically conjugate biochemical or biophysical labels to these ncAAs. As a proof-of-principle, we have used this method to generate unique single-molecule fluorescence resonance energy transfer (smFRET) signals reporting on ribosome structural dynamics that have thus far remained inaccessible to smFRET studies of translation.
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30
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The structural basis for inhibition of ribosomal translocation by viomycin. Proc Natl Acad Sci U S A 2020; 117:10271-10277. [PMID: 32341159 DOI: 10.1073/pnas.2002888117] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Viomycin, an antibiotic that has been used to fight tuberculosis infections, is believed to block the translocation step of protein synthesis by inhibiting ribosomal subunit dissociation and trapping the ribosome in an intermediate state of intersubunit rotation. The mechanism by which viomycin stabilizes this state remains unexplained. To address this, we have determined cryo-EM and X-ray crystal structures of Escherichia coli 70S ribosome complexes trapped in a rotated state by viomycin. The 3.8-Å resolution cryo-EM structure reveals a ribosome trapped in the hybrid state with 8.6° intersubunit rotation and 5.3° rotation of the 30S subunit head domain, bearing a single P/E state transfer RNA (tRNA). We identify five different binding sites for viomycin, four of which have not been previously described. To resolve the details of their binding interactions, we solved the 3.1-Å crystal structure of a viomycin-bound ribosome complex, revealing that all five viomycins bind to ribosomal RNA. One of these (Vio1) corresponds to the single viomycin that was previously identified in a complex with a nonrotated classical-state ribosome. Three of the newly observed binding sites (Vio3, Vio4, and Vio5) are clustered at intersubunit bridges, consistent with the ability of viomycin to inhibit subunit dissociation. We propose that one or more of these same three viomycins induce intersubunit rotation by selectively binding the rotated state of the ribosome at dynamic elements of 16S and 23S rRNA, thus, blocking conformational changes associated with molecular movements that are required for translocation.
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31
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Fenwick MK, Ealick SE. Structural basis of elongation factor 2 switching. Curr Res Struct Biol 2020; 2:25-34. [PMID: 34235467 PMCID: PMC8244253 DOI: 10.1016/j.crstbi.2020.02.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Revised: 02/07/2020] [Accepted: 02/14/2020] [Indexed: 12/13/2022] Open
Abstract
Archaebacterial and eukaryotic elongation factor 2 (EF-2) and bacterial elongation factor G (EF-G) are five domain GTPases that catalyze the ribosomal translocation of tRNA and mRNA. In the classical mechanism of activation, GTPases are switched on through GDP/GTP exchange, which is accompanied by the ordering of two flexible segments called switch I and II. However, crystal structures of EF-2 and EF-G have thus far not revealed the conformations required by the classical mechanism. Here, we describe crystal structures of Methanoperedens nitroreducens EF-2 (MnEF-2) and MnEF-2-H595N bound to GMPPCP (GppCp) and magnesium displaying previously unreported compact conformations. Domain III forms interfaces with the other four domains and the overall conformations resemble that of SNU114, the eukaryotic spliceosomal GTPase. The gamma phosphate of GMPPCP is detected through interactions with switch I and a P-loop structural element. Switch II is highly ordered whereas switch I shows a variable degree of ordering. The ordered state results in a tight interdomain arrangement of domains I-III and the formation of a portion of a predicted monovalent cation site involving the P-loop and switch I. The side chain of an essential histidine residue in switch II is placed in the inactive conformation observed for the “on” state of elongation factor EF-Tu. The compact conformations of MnEF-2 and MnEF-2-H595N suggest an “on” ribosome-free conformational state. Crystal structures of ribosome-free elongation factor 2 (EF-2) bound to GTP analog and magnesium. Compact conformation and P-loop, switch I, and switch II structures suggest “on” state. Arrangement of domains I-III similar to that of ribosome-bound EF-2/EF-G complexed with GTP analog. Switch II histidine shows inactive conformation observed for “on” state of ribosome-free EF-Tu.
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Affiliation(s)
- Michael K Fenwick
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, 14853, USA
| | - Steven E Ealick
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, 14853, USA
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32
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Chang KC, Salawu EO, Chang YY, Wen JD, Yang LW. Resolution-exchanged structural modeling and simulations jointly unravel that subunit rolling underlies the mechanism of programmed ribosomal frameshifting. Bioinformatics 2019; 35:945-952. [PMID: 30169551 DOI: 10.1093/bioinformatics/bty762] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Revised: 07/26/2018] [Accepted: 08/28/2018] [Indexed: 12/20/2022] Open
Abstract
MOTIVATION Programmed ribosomal frameshifting (PRF) is widely used by viruses and bacteria to produce different proteins from a single mRNA template. How steric hindrance of a PRF-stimulatory mRNA structure transiently modifies the conformational dynamics of the ribosome, and thereby allows tRNA slippage, remains elusive. RESULTS Here, we leverage linear response theories and resolution-exchanged simulations to construct a structural/dynamics model that connects and rationalizes existing structural, single-molecule and mutagenesis data by resolution-exchanged structural modelling and simulations. Our combined theoretical techniques provide a temporal and spatial description of PRF with unprecedented mechanistic details. We discover that ribosomal unfolding of the PRF-stimulating pseudoknot exerts resistant forces on the mRNA entrance of the ribosome, and thereby drives 30S subunit rolling. Such motion distorts tRNAs, leads to tRNA slippage, and in turn serves as a delicate control of cis-element's unwinding forces over PRF. AVAILABILITY AND IMPLEMENTATION All the simulation scripts and computational implementations of our methods/analyses (including linear response theory) are included in the bioStructureM suite, provided through GitHub at https://github.com/Yuan-Yu/bioStructureM. SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Kai-Chun Chang
- Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, Taiwan
| | - Emmanuel Oluwatobi Salawu
- Institute of Bioinformatics and Structural Biology, National Tsing Hua University, Hsinchu, Taiwan.,TIGP Bioinformatics Program, Institute of Information Sciences, Academia Sinica, Taipei, Taiwan
| | - Yuan-Yu Chang
- Institute of Bioinformatics and Structural Biology, National Tsing Hua University, Hsinchu, Taiwan
| | - Jin-Der Wen
- Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, Taiwan
| | - Lee-Wei Yang
- Institute of Bioinformatics and Structural Biology, National Tsing Hua University, Hsinchu, Taiwan.,TIGP Bioinformatics Program, Institute of Information Sciences, Academia Sinica, Taipei, Taiwan.,Physics Division, National Center for Theoretical Sciences, Hsinchu, Taiwan
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33
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Structural basis for ribosome recycling by RRF and tRNA. Nat Struct Mol Biol 2019; 27:25-32. [PMID: 31873307 DOI: 10.1038/s41594-019-0350-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Accepted: 11/12/2019] [Indexed: 11/08/2022]
Abstract
The bacterial ribosome is recycled into subunits by two conserved proteins, elongation factor G (EF-G) and the ribosome recycling factor (RRF). The molecular basis for ribosome recycling by RRF and EF-G remains unclear. Here, we report the crystal structure of a posttermination Thermus thermophilus 70S ribosome complexed with EF-G, RRF and two transfer RNAs at a resolution of 3.5 Å. The deacylated tRNA in the peptidyl (P) site moves into a previously unsuspected state of binding (peptidyl/recycling, p/R) that is analogous to that seen during initiation. The terminal end of the p/R-tRNA forms nonfavorable contacts with the 50S subunit while RRF wedges next to central inter-subunit bridges, illuminating the active roles of tRNA and RRF in dissociation of ribosomal subunits. The structure uncovers a missing snapshot of tRNA as it transits between the P and exit (E) sites, providing insights into the mechanisms of ribosome recycling and tRNA translocation.
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34
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Chan J, Takemura K, Lin HR, Chang KC, Chang YY, Joti Y, Kitao A, Yang LW. An Efficient Timer and Sizer of Biomacromolecular Motions. Structure 2019; 28:259-269.e8. [PMID: 31780433 DOI: 10.1016/j.str.2019.10.020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2019] [Revised: 08/22/2019] [Accepted: 10/30/2019] [Indexed: 11/28/2022]
Abstract
Life ticks as fast as how proteins move. Computationally expensive molecular dynamics simulation has been the only theoretical tool to gauge the time and sizes of these motions, though barely to their slowest ends. Here, we convert a computationally cheap elastic network model (ENM) into a molecular timer and sizer to gauge the slowest functional motions of structured biomolecules. Quasi-harmonic analysis, fluctuation profile matching, and the Wiener-Khintchine theorem are used to define the "time periods," t, for anharmonic principal components (PCs), which are validated by nuclear magnetic resonance (NMR) order parameters. The PCs with their respective "time periods" are mapped to the eigenvalues (λENM) of the corresponding ENM modes. Thus, the power laws t(ns) = 56.1λENM-1.6 and σ2(Å2) = 32.7λENM-3.0 can be established allowing the characterization of the timescales of NMR-resolved conformers, crystallographic anisotropic displacement parameters, and important ribosomal motions, as well as motional sizes of the latter.
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Affiliation(s)
- Justin Chan
- Institute of Bioinformatics and Structural Biology, National Tsing Hua Univ., No. 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan; Bioinformatics Program, Taiwan International Graduate Program, Institute of Information Science, Academia Sinica, Taipei, Taiwan
| | - Kazuhiro Takemura
- School of Life Science and Technology, Tokyo Institute of Technology, M6-13, 2-12-1 Ookayama, Meguro, Tokyo 152-8550, Japan
| | - Hong-Rui Lin
- Institute of Bioinformatics and Structural Biology, National Tsing Hua Univ., No. 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan
| | - Kai-Chun Chang
- Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, Taiwan
| | - Yuan-Yu Chang
- Institute of Bioinformatics and Structural Biology, National Tsing Hua Univ., No. 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan
| | - Yasumasa Joti
- XFEL Utilization Division, Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan
| | - Akio Kitao
- School of Life Science and Technology, Tokyo Institute of Technology, M6-13, 2-12-1 Ookayama, Meguro, Tokyo 152-8550, Japan.
| | - Lee-Wei Yang
- Institute of Bioinformatics and Structural Biology, National Tsing Hua Univ., No. 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan; Bioinformatics Program, Taiwan International Graduate Program, Institute of Information Science, Academia Sinica, Taipei, Taiwan; Physics Division, National Center for Theoretical Sciences, Hsinchu, Taiwan.
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35
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Ribosome collisions alter frameshifting at translational reprogramming motifs in bacterial mRNAs. Proc Natl Acad Sci U S A 2019; 116:21769-21779. [PMID: 31591196 PMCID: PMC6815119 DOI: 10.1073/pnas.1910613116] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Ribosomes move along mRNAs in 3-nucleotide steps as they interpret codons that specify which amino acid is required at each position in the protein. There are multiple examples of genes with DNA sequences that do not match the produced proteins because ribosomes move to a new reading frame in the message before finishing translation (so-called frameshifting). This report shows that, when ribosomes stall at mRNA regions prone to cause frameshifting events, trailing ribosomes that collide with them can significantly change the outcome and potentially regulate protein production. This work highlights the principle that biological macromolecules do not function in isolation, and it provides an example of how physical interactions between neighboring complexes can be used to augment their performance. Translational frameshifting involves the repositioning of ribosomes on their messages into decoding frames that differ from those dictated during initiation. Some messenger RNAs (mRNAs) contain motifs that promote deliberate frameshifting to regulate production of the encoded proteins. The mechanisms of frameshifting have been investigated in many systems, and the resulting models generally involve single ribosomes responding to stimulator sequences in their engaged mRNAs. We discovered that the abundance of ribosomes on messages containing the IS3, dnaX, and prfB frameshift motifs significantly influences the levels of frameshifting. We show that this phenomenon results from ribosome collisions that occur during translational stalling, which can alter frameshifting in both the stalled and trailing ribosomes. Bacteria missing ribosomal protein bL9 are known to exhibit a reduction in reading frame maintenance and to have a strong dependence on elongation factor P (EFP). We discovered that ribosomes lacking bL9 become compacted closer together during collisions and that the E-sites of the stalled ribosomes appear to become blocked, which suggests subsequent transpeptidation in transiently stalled ribosomes may become compromised in the absence of bL9. In addition, we determined that bL9 can suppress frameshifting of its host ribosome, likely by regulating E-site dynamics. These findings provide mechanistic insight into the behavior of colliding ribosomes during translation and suggest naturally occurring frameshift elements may be regulated by the abundance of ribosomes relative to an mRNA pool.
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36
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Probing the dynamic stalk region of the ribosome using solution NMR. Sci Rep 2019; 9:13528. [PMID: 31537834 PMCID: PMC6753160 DOI: 10.1038/s41598-019-49190-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Accepted: 07/31/2019] [Indexed: 11/29/2022] Open
Abstract
We describe an NMR approach based on the measurement of residual dipolar couplings (RDCs) to probe the structural and motional properties of the dynamic regions of the ribosome. Alignment of intact 70S ribosomes in filamentous bacteriophage enabled measurement of RDCs in the mobile C-terminal domain (CTD) of the stalk protein bL12. A structural refinement of this domain using the observed RDCs did not show large changes relative to the isolated protein in the absence of the ribosome, and we also found that alignment of the CTD was almost independent of the presence of the core ribosome particle, indicating that the inter-domain linker has significant flexibility. The nature of this linker was subsequently probed in more detail using a paramagnetic alignment strategy, which revealed partial propagation of alignment between neighbouring domains, providing direct experimental validation of a structural ensemble previously derived from SAXS and NMR relaxation measurements. Our results demonstrate the prospect of better characterising dynamical and functional regions of more challenging macromolecular machines and systems, for example ribosome–nascent chain complexes.
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37
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Svidritskiy E, Demo G, Loveland AB, Xu C, Korostelev AA. Extensive ribosome and RF2 rearrangements during translation termination. eLife 2019; 8:46850. [PMID: 31513010 PMCID: PMC6742477 DOI: 10.7554/elife.46850] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 08/28/2019] [Indexed: 12/31/2022] Open
Abstract
Protein synthesis ends when a ribosome reaches an mRNA stop codon. Release factors (RFs) decode the stop codon, hydrolyze peptidyl-tRNA to release the nascent protein, and then dissociate to allow ribosome recycling. To visualize termination by RF2, we resolved a cryo-EM ensemble of E. coli 70S•RF2 structures at up to 3.3 Å in a single sample. Five structures suggest a highly dynamic termination pathway. Upon peptidyl-tRNA hydrolysis, the CCA end of deacyl-tRNA departs from the peptidyl transferase center. The catalytic GGQ loop of RF2 is rearranged into a long β-hairpin that plugs the peptide tunnel, biasing a nascent protein toward the ribosome exit. Ribosomal intersubunit rotation destabilizes the catalytic RF2 domain on the 50S subunit and disassembles the central intersubunit bridge B2a, resulting in RF2 departure. Our structures visualize how local rearrangements and spontaneous inter-subunit rotation poise the newly-made protein and RF2 to dissociate in preparation for ribosome recycling.
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Affiliation(s)
- Egor Svidritskiy
- RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, United States
| | - Gabriel Demo
- RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, United States
| | - Anna B Loveland
- RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, United States
| | - Chen Xu
- Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, United States
| | - Andrei A Korostelev
- RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, United States.,Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, United States
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38
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Sengupta A, Rice GM, Weeks KM. Single-molecule correlated chemical probing reveals large-scale structural communication in the ribosome and the mechanism of the antibiotic spectinomycin in living cells. PLoS Biol 2019; 17:e3000393. [PMID: 31487286 PMCID: PMC6748448 DOI: 10.1371/journal.pbio.3000393] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 09/17/2019] [Accepted: 08/14/2019] [Indexed: 11/18/2022] Open
Abstract
The ribosome moves between distinct structural states and is organized into multiple functional domains. Here, we examined hundreds of occurrences of pairwise through-space communication between nucleotides in the ribosome small subunit RNA using RNA interaction groups analyzed by mutational profiling (RING-MaP) single-molecule correlated chemical probing in bacterial cells. RING-MaP revealed four structural communities in the small subunit RNA, each distinct from the organization defined by the RNA secondary structure. The head domain contains 2 structural communities: the outer-head contains the pivot for head swiveling, and an inner-head community is structurally integrated with helix 44 and spans the entire ribosome intersubunit interface. In-cell binding by the antibiotic spectinomycin (Spc) barely perturbs its local binding pocket as revealed by the per-nucleotide chemical probing signal. In contrast, Spc binding overstabilizes long-range RNA–RNA contacts that extend 95 Å across the ribosome that connect the pivot for head swiveling with the axis of intersubunit rotation. The two major motions of the small subunit—head swiveling and intersubunit rotation—are thus coordinated via long-range RNA structural communication, which is specifically modulated by Spc. Single-molecule correlated chemical probing reveals trans-domain structural communication and rationalizes the profound functional effects of binding by a low–molecular-mass antibiotic to the megadalton ribosome. Single molecule chemical probing of pair-wise interactions across the ribosome in living cells redefines the domains of the small subunit of the ribosome and reveals that the antibiotic spectinomycin disrupts ribosome function by over-stabilizing interactions that span nearly 100 Å.
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Affiliation(s)
- Arnab Sengupta
- Department of Chemistry, University of North Carolina Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Greggory M. Rice
- Department of Chemistry, University of North Carolina Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Kevin M. Weeks
- Department of Chemistry, University of North Carolina Chapel Hill, Chapel Hill, North Carolina, United States of America
- * E-mail:
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39
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Abstract
The large ribosomal subunit has a distinct feature, the stalk, extending outside the ribosome. In bacteria it is called the L12 stalk. The base of the stalk is protein uL10 to which two or three dimers of proteins bL12 bind. In archea and eukarya P1 and P2 proteins constitute the stalk. All these extending proteins, that have a high degree of flexibility due to a hinge between their N- and C-terminal parts, are essential for proper functionalization of some of the translation factors. The role of the stalk proteins has remained enigmatic for decades but is gradually approaching an understanding. In this review we summarise the knowhow about the structure and function of the ribosomal stalk till date starting from the early phase of ribosome research.
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40
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Desai VP, Frank F, Lee A, Righini M, Lancaster L, Noller HF, Tinoco I, Bustamante C. Co-temporal Force and Fluorescence Measurements Reveal a Ribosomal Gear Shift Mechanism of Translation Regulation by Structured mRNAs. Mol Cell 2019; 75:1007-1019.e5. [PMID: 31471187 DOI: 10.1016/j.molcel.2019.07.024] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 06/12/2019] [Accepted: 07/15/2019] [Indexed: 11/18/2022]
Abstract
The movement of ribosomes on mRNA is often interrupted by secondary structures that present mechanical barriers and play a central role in translation regulation. We investigate how ribosomes couple their internal conformational changes with the activity of translocation factor EF-G to unwind mRNA secondary structures using high-resolution optical tweezers with single-molecule fluorescence capability. We find that hairpin opening occurs during EF-G-catalyzed translocation and is driven by the forward rotation of the small subunit head. Modulating the magnitude of the hairpin barrier by force shows that ribosomes respond to strong barriers by shifting their operation to an alternative 7-fold-slower kinetic pathway prior to translocation. Shifting into a slow gear results from an allosteric switch in the ribosome that may allow it to exploit thermal fluctuations to overcome mechanical barriers. Finally, we observe that ribosomes occasionally open the hairpin in two successive sub-codon steps, revealing a previously unobserved translocation intermediate.
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Affiliation(s)
- Varsha P Desai
- Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA; Jason L. Choy Laboratory of Single-Molecule Biophysics, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Filipp Frank
- Jason L. Choy Laboratory of Single-Molecule Biophysics, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Antony Lee
- Jason L. Choy Laboratory of Single-Molecule Biophysics, University of California, Berkeley, Berkeley, CA 94720, USA; Department of Physics, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Maurizio Righini
- Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA; Jason L. Choy Laboratory of Single-Molecule Biophysics, University of California, Berkeley, Berkeley, CA 94720, USA; California Institute for Quantitative Biosciences, QB3, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Laura Lancaster
- Department of Molecular, Cell, and Developmental Biology and Center for Molecular Biology of RNA, University of California, Santa Cruz, Santa Cruz, CA 95064, USA
| | - Harry F Noller
- Department of Molecular, Cell, and Developmental Biology and Center for Molecular Biology of RNA, University of California, Santa Cruz, Santa Cruz, CA 95064, USA
| | - Ignacio Tinoco
- Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Carlos Bustamante
- Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA; Jason L. Choy Laboratory of Single-Molecule Biophysics, University of California, Berkeley, Berkeley, CA 94720, USA; Department of Physics, University of California, Berkeley, Berkeley, CA 94720, USA; California Institute for Quantitative Biosciences, QB3, University of California, Berkeley, Berkeley, CA 94720, USA; Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA 94720, USA; Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA; Kavli Energy Nanoscience Institute, University of California, Berkeley, Berkeley, CA 94720, USA.
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41
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Tanzawa T, Kato K, Girodat D, Ose T, Kumakura Y, Wieden HJ, Uchiumi T, Tanaka I, Yao M. The C-terminal helix of ribosomal P stalk recognizes a hydrophobic groove of elongation factor 2 in a novel fashion. Nucleic Acids Res 2019; 46:3232-3244. [PMID: 29471537 PMCID: PMC5887453 DOI: 10.1093/nar/gky115] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Accepted: 02/09/2018] [Indexed: 01/17/2023] Open
Abstract
Archaea and eukaryotes have ribosomal P stalks composed of anchor protein P0 and aP1 homodimers (archaea) or P1•P2 heterodimers (eukaryotes). These P stalks recruit translational GTPases to the GTPase-associated center in ribosomes to provide energy during translation. The C-terminus of the P stalk is known to selectively recognize GTPases. Here we investigated the interaction between the P stalk and elongation factor 2 by determining the structures of Pyrococcus horikoshii EF-2 (PhoEF-2) in the Apo-form, GDP-form, GMPPCP-form (GTP-form), and GMPPCP-form bound with 11 C-terminal residues of P1 (P1C11). Helical structured P1C11 binds to a hydrophobic groove between domain G and subdomain G′ of PhoEF-2, where is completely different from that of aEF-1α in terms of both position and sequence, implying that such interaction characteristic may be requested by how GTPases perform their functions on the ribosome. Combining PhoEF-2 P1-binding assays with a structural comparison of current PhoEF-2 structures and molecular dynamics model of a P1C11-bound GDP form, the conformational changes of the P1C11-binding groove in each form suggest that in response to the translation process, the groove has three states: closed, open, and release for recruiting and releasing GTPases.
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Affiliation(s)
- Takehito Tanzawa
- Graduate School of Life Science, Hokkaido University, Sapporo, Hokkaido 060-0810, Japan
| | - Koji Kato
- Graduate School of Life Science, Hokkaido University, Sapporo, Hokkaido 060-0810, Japan.,Faculty of Advanced Life Science, Hokkaido University, Sapporo, Hokkaido 060-0810, Japan
| | - Dylan Girodat
- Alberta RNA Research and Training Institute, Department of Chemistry and Biochemistry, University of Lethbridge, Lethbridge AB T1K 3M4, Canada
| | - Toyoyuki Ose
- Graduate School of Life Science, Hokkaido University, Sapporo, Hokkaido 060-0810, Japan.,Faculty of Advanced Life Science, Hokkaido University, Sapporo, Hokkaido 060-0810, Japan
| | - Yuki Kumakura
- Graduate School of Life Science, Hokkaido University, Sapporo, Hokkaido 060-0810, Japan
| | - Hans-Joachim Wieden
- Alberta RNA Research and Training Institute, Department of Chemistry and Biochemistry, University of Lethbridge, Lethbridge AB T1K 3M4, Canada
| | - Toshio Uchiumi
- Department of Biology, Faculty of Science, Niigata University, 8050 Ikarashi 2-no-cho, Nishi-ku, Niigata 950-2181, Japan
| | - Isao Tanaka
- Faculty of Advanced Life Science, Hokkaido University, Sapporo, Hokkaido 060-0810, Japan
| | - Min Yao
- Graduate School of Life Science, Hokkaido University, Sapporo, Hokkaido 060-0810, Japan.,Faculty of Advanced Life Science, Hokkaido University, Sapporo, Hokkaido 060-0810, Japan
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42
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Macé K, Giudice E, Chat S, Gillet R. The structure of an elongation factor G-ribosome complex captured in the absence of inhibitors. Nucleic Acids Res 2019; 46:3211-3217. [PMID: 29408956 PMCID: PMC5887593 DOI: 10.1093/nar/gky081] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 01/27/2018] [Indexed: 12/25/2022] Open
Abstract
During translation’s elongation cycle, elongation factor G (EF-G) promotes messenger and transfer RNA translocation through the ribosome. Until now, the structures reported for EF-G–ribosome complexes have been obtained by trapping EF-G in the ribosome. These results were based on use of non-hydrolyzable guanosine 5′-triphosphate (GTP) analogs, specific inhibitors or a mutated EF-G form. Here, we present the first cryo-electron microscopy structure of EF-G bound to ribosome in the absence of an inhibitor. The structure reveals a natural conformation of EF-G·GDP in the ribosome, with a previously unseen conformation of its third domain. These data show how EF-G must affect translocation, and suggest the molecular mechanism by which fusidic acid antibiotic prevents the release of EF-G after GTP hydrolysis.
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Affiliation(s)
- Kevin Macé
- Univ. Rennes, CNRS, Institut de Génétique et de Développement de Rennes (IGDR), UMR6290, F35000 Rennes, France
| | - Emmanuel Giudice
- Univ. Rennes, CNRS, Institut de Génétique et de Développement de Rennes (IGDR), UMR6290, F35000 Rennes, France
| | - Sophie Chat
- Univ. Rennes, CNRS, Institut de Génétique et de Développement de Rennes (IGDR), UMR6290, F35000 Rennes, France
| | - Reynald Gillet
- Univ. Rennes, CNRS, Institut de Génétique et de Développement de Rennes (IGDR), UMR6290, F35000 Rennes, France
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43
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Choi J, Grosely R, Prabhakar A, Lapointe CP, Wang J, Puglisi JD. How Messenger RNA and Nascent Chain Sequences Regulate Translation Elongation. Annu Rev Biochem 2019; 87:421-449. [PMID: 29925264 DOI: 10.1146/annurev-biochem-060815-014818] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Translation elongation is a highly coordinated, multistep, multifactor process that ensures accurate and efficient addition of amino acids to a growing nascent-peptide chain encoded in the sequence of translated messenger RNA (mRNA). Although translation elongation is heavily regulated by external factors, there is clear evidence that mRNA and nascent-peptide sequences control elongation dynamics, determining both the sequence and structure of synthesized proteins. Advances in methods have driven experiments that revealed the basic mechanisms of elongation as well as the mechanisms of regulation by mRNA and nascent-peptide sequences. In this review, we highlight how mRNA and nascent-peptide elements manipulate the translation machinery to alter the dynamics and pathway of elongation.
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Affiliation(s)
- Junhong Choi
- Department of Structural Biology, Stanford University School of Medicine, Stanford, California 94305-5126, USA; , , , , , .,Department of Applied Physics, Stanford University, Stanford, California 94305-4090, USA
| | - Rosslyn Grosely
- Department of Structural Biology, Stanford University School of Medicine, Stanford, California 94305-5126, USA; , , , , ,
| | - Arjun Prabhakar
- Department of Structural Biology, Stanford University School of Medicine, Stanford, California 94305-5126, USA; , , , , , .,Program in Biophysics, Stanford University, Stanford, California 94305, USA
| | - Christopher P Lapointe
- Department of Structural Biology, Stanford University School of Medicine, Stanford, California 94305-5126, USA; , , , , ,
| | - Jinfan Wang
- Department of Structural Biology, Stanford University School of Medicine, Stanford, California 94305-5126, USA; , , , , ,
| | - Joseph D Puglisi
- Department of Structural Biology, Stanford University School of Medicine, Stanford, California 94305-5126, USA; , , , , ,
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44
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Klimova M, Senyushkina T, Samatova E, Peng BZ, Pearson M, Peske F, Rodnina MV. EF-G-induced ribosome sliding along the noncoding mRNA. SCIENCE ADVANCES 2019; 5:eaaw9049. [PMID: 31183409 PMCID: PMC6551183 DOI: 10.1126/sciadv.aaw9049] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 04/25/2019] [Indexed: 05/02/2023]
Abstract
Translational bypassing is a recoding event during which ribosomes slide over a noncoding region of the messenger RNA (mRNA) to synthesize one protein from two discontinuous reading frames. Structures in the mRNA orchestrate forward movement of the ribosome, but what causes ribosomes to start sliding remains unclear. Here, we show that elongation factor G (EF-G) triggers ribosome take-off by a pseudotranslocation event using a small mRNA stem-loop as an A-site transfer RNA mimic and requires hydrolysis of about two molecules of guanosine 5'-triphosphate per nucleotide of the noncoding gap. Bypassing ribosomes adopt a hyper-rotated conformation, also observed with ribosomes stalled by the SecM sequence, suggesting common ribosome dynamics during translation stalling. Our results demonstrate a new function of EF-G in promoting ribosome sliding along the mRNA, in contrast to codon-wise ribosome movement during canonical translation, and suggest a mechanism by which ribosomes could traverse untranslated parts of mRNAs.
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45
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How Ricin Damages the Ribosome. Toxins (Basel) 2019; 11:toxins11050241. [PMID: 31035546 PMCID: PMC6562825 DOI: 10.3390/toxins11050241] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2019] [Revised: 04/17/2019] [Accepted: 04/24/2019] [Indexed: 12/20/2022] Open
Abstract
Ricin belongs to the group of ribosome-inactivating proteins (RIPs), i.e., toxins that have evolved to provide particular species with an advantage over other competitors in nature. Ricin possesses RNA N-glycosidase activity enabling the toxin to eliminate a single adenine base from the sarcin-ricin RNA loop (SRL), which is a highly conserved structure present on the large ribosomal subunit in all species from the three domains of life. The SRL belongs to the GTPase associated center (GAC), i.e., a ribosomal element involved in conferring unidirectional trajectory for the translational apparatus at the expense of GTP hydrolysis by translational GTPases (trGTPases). The SRL represents a critical element in the GAC, being the main triggering factor of GTP hydrolysis by trGTPases. Enzymatic removal of a single adenine base at the tip of SRL by ricin blocks GTP hydrolysis and, at the same time, impedes functioning of the translational machinery. Here, we discuss the consequences of SRL depurination by ricin for ribosomal performance, with emphasis on the mechanistic model overview of the SRL modus operandi.
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46
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Spontaneous ribosomal translocation of mRNA and tRNAs into a chimeric hybrid state. Proc Natl Acad Sci U S A 2019; 116:7813-7818. [PMID: 30936299 DOI: 10.1073/pnas.1901310116] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
The elongation factor G (EF-G)-catalyzed translocation of mRNA and tRNA through the ribosome is essential for vacating the ribosomal A site for the next incoming aminoacyl-tRNA, while precisely maintaining the translational reading frame. Here, the 3.2-Å crystal structure of a ribosome translocation intermediate complex containing mRNA and two tRNAs, formed in the absence of EF-G or GTP, provides insight into the respective roles of EF-G and the ribosome in translocation. Unexpectedly, the head domain of the 30S subunit is rotated by 21°, creating a ribosomal conformation closely resembling the two-tRNA chimeric hybrid state that was previously observed only in the presence of bound EF-G. The two tRNAs have moved spontaneously from their A/A and P/P binding states into ap/P and pe/E states, in which their anticodon loops are bound between the 30S body domain and its rotated head domain, while their acceptor ends have moved fully into the 50S P and E sites, respectively. Remarkably, the A-site tRNA translocates fully into the classical P-site position. Although the mRNA also undergoes movement, codon-anticodon interaction is disrupted in the absence of EF-G, resulting in slippage of the translational reading frame. We conclude that, although movement of both tRNAs and mRNA (along with rotation of the 30S head domain) can occur in the absence of EF-G and GTP, EF-G is essential for enforcing coupled movement of the tRNAs and their mRNA codons to maintain the reading frame.
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47
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Abstract
In the past 4 years, because of the advent of new cameras, many ribosome structures have been solved by cryoelectron microscopy (cryo-EM) at high, often near-atomic resolution, bringing new mechanistic insights into the processes of translation initiation, peptide elongation, termination, and recycling. Thus, cryo-EM has joined X-ray crystallography as a powerful technique in structural studies of translation. The significance of this new development is that structures of ribosomes in complex with their functional binding partners can now be determined to high resolution in multiple states as they perform their work. The aim of this article is to provide an overview of these new studies and assess the contributions they have made toward an understanding of translation and translational control.
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48
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Flis J, Holm M, Rundlet EJ, Loerke J, Hilal T, Dabrowski M, Bürger J, Mielke T, Blanchard SC, Spahn CMT, Budkevich TV. tRNA Translocation by the Eukaryotic 80S Ribosome and the Impact of GTP Hydrolysis. Cell Rep 2018; 25:2676-2688.e7. [PMID: 30517857 PMCID: PMC6314685 DOI: 10.1016/j.celrep.2018.11.040] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 09/14/2018] [Accepted: 11/09/2018] [Indexed: 01/04/2023] Open
Abstract
Translocation moves the tRNA2⋅mRNA module directionally through the ribosome during the elongation phase of protein synthesis. Although translocation is known to entail large conformational changes within both the ribosome and tRNA substrates, the orchestrated events that ensure the speed and fidelity of this critical aspect of the protein synthesis mechanism have not been fully elucidated. Here, we present three high-resolution structures of intermediates of translocation on the mammalian ribosome where, in contrast to bacteria, ribosomal complexes containing the translocase eEF2 and the complete tRNA2⋅mRNA module are trapped by the non-hydrolyzable GTP analog GMPPNP. Consistent with the observed structures, single-molecule imaging revealed that GTP hydrolysis principally facilitates rate-limiting, final steps of translocation, which are required for factor dissociation and which are differentially regulated in bacterial and mammalian systems by the rates of deacyl-tRNA dissociation from the E site.
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Affiliation(s)
- Julia Flis
- Institut für Medizinische Physik und Biophysik, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
| | - Mikael Holm
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY, USA
| | - Emily J Rundlet
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY, USA; Tri-Institutional PhD Program in Chemical Biology, Weill Cornell Medicine, New York, NY, USA
| | - Justus Loerke
- Institut für Medizinische Physik und Biophysik, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
| | - Tarek Hilal
- Institut für Medizinische Physik und Biophysik, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
| | - Marylena Dabrowski
- Institut für Medizinische Physik und Biophysik, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
| | - Jörg Bürger
- Institut für Medizinische Physik und Biophysik, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany; UltraStrukturNetzwerk, Max Planck Institute for Molecular Genetics, 14195 Berlin, Germany
| | - Thorsten Mielke
- UltraStrukturNetzwerk, Max Planck Institute for Molecular Genetics, 14195 Berlin, Germany
| | - Scott C Blanchard
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY, USA; Tri-Institutional PhD Program in Chemical Biology, Weill Cornell Medicine, New York, NY, USA.
| | - Christian M T Spahn
- Institut für Medizinische Physik und Biophysik, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany.
| | - Tatyana V Budkevich
- Institut für Medizinische Physik und Biophysik, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany.
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49
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Wang J, Zhou J, Yang Q, Grayhack EJ. Multi-protein bridging factor 1(Mbf1), Rps3 and Asc1 prevent stalled ribosomes from frameshifting. eLife 2018; 7:39637. [PMID: 30465652 PMCID: PMC6301793 DOI: 10.7554/elife.39637] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 11/21/2018] [Indexed: 12/17/2022] Open
Abstract
Reading frame maintenance is critical for accurate translation. We show that the conserved eukaryotic/archaeal protein Mbf1 acts with ribosomal proteins Rps3/uS3 and eukaryotic Asc1/RACK1 to prevent frameshifting at inhibitory CGA-CGA codon pairs in the yeast Saccharomyces cerevisiae. Mutations in RPS3 that allow frameshifting implicate eukaryotic conserved residues near the mRNA entry site. Mbf1 and Rps3 cooperate to maintain the reading frame of stalled ribosomes, while Asc1 also mediates distinct events that result in recruitment of the ribosome quality control complex and mRNA decay. Frameshifting occurs through a +1 shift with a CGA codon in the P site and involves competition between codons entering the A site, implying that the wobble interaction of the P site codon destabilizes translation elongation. Thus, eukaryotes have evolved unique mechanisms involving both a universally conserved ribosome component and two eukaryotic-specific proteins to maintain the reading frame at ribosome stalls. Proteins perform all the chemical reactions needed to keep a cell alive; thus, it is essential to assemble them correctly. They are made by molecular machines called ribosomes, which follow a sequence of instructions written in genetic code in molecules known as mRNAs. Ribosomes essentially read the genetic code three letters at a time; each triplet either codes for the insertion of one of 20 building blocks into the emerging protein, or serves as a signal to stop the process. It is critical that, after reading one triplet, the ribosome moves precisely three letters to read the next triplet. If, for example, the ribosome shifted just two letters instead of three – a phenomenon known as “frameshifting” – it would completely change the building blocks that were used to make the protein. This could lead to atypical or aberrant proteins that either do not work or are even toxic to the cell. For a variety of reasons, ribosomes will often stall before they have finished building a protein. When this happens, the ribosome is more likely to frameshift. Cells commonly respond to stalled ribosomes by recruiting other molecules that work as quality control systems, some of which can disassemble the ribosome and break down the mRNA. In budding yeast, one part of the ribosome – named Asc1 – plays a key role in recruiting these quality control systems and in mRNA breakdown. If this component is removed, stalled ribosomes frameshift more frequently and, as a result, aberrant proteins accumulate in the cell. Since the Asc1 recruiter protein sits on the outside of the ribosome, it seemed likely that it might act through other factors to stop the ribosome from frameshifting when it stalls. However, it was unknown if such factors exist, what they are, or how they might work. Now, Wang et al. have identified two additional yeast proteins, named Mbf1 and Rps3, which cooperate to stop the ribosome from frameshifting after it stalls. Rps3, like Asc1, is a component of the ribosome, while Mbf1 is not. It appears that Rps3 likely stops frameshifting via an interaction with the incoming mRNA, because a region of Rps3 near the mRNA entry site to the ribosome is important for its activity. Further experiments then showed that the known Asc1-mediated breakdown of mRNAs did not depend on Mbf1 and Rps3, but also assists in stopping frameshifting. Thus, frameshifting of stalled ribosomes is prevented via two distinct ways: one that directly involves Mbf1 and Rps3 and one that is promoted by Asc1, which reduces the amounts of mRNAs on which ribosomes frameshift. These newly identified factors may provide insights into the precisely controlled protein-production machinery in the cell and into roles of the quality control systems. An improved understanding of mechanisms that prevent frameshifting could eventually lead to better treatments for some human diseases that result when these processes go awry, which include certain neurological conditions.
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Affiliation(s)
- Jiyu Wang
- Department of Biochemistry and Biophysics, School of Medicine and Dentistry, University of Rochester, Rochester, New York.,Center for RNA Biology, University of Rochester, Rochester, New York
| | - Jie Zhou
- Department of Biochemistry and Biophysics, School of Medicine and Dentistry, University of Rochester, Rochester, New York
| | - Qidi Yang
- Department of Biochemistry and Biophysics, School of Medicine and Dentistry, University of Rochester, Rochester, New York
| | - Elizabeth J Grayhack
- Department of Biochemistry and Biophysics, School of Medicine and Dentistry, University of Rochester, Rochester, New York.,Center for RNA Biology, University of Rochester, Rochester, New York
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50
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Kürkçüoğlu Ö. Exploring allosteric communication in multiple states of the bacterial ribosome using residue network analysis. Turk J Biol 2018; 42:392-404. [PMID: 30930623 PMCID: PMC6438126 DOI: 10.3906/biy-1802-77] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Antibiotic resistance is one of the most important problems of our era and hence the discovery of new effective therapeutics is urgent. At this point, studying the allosteric communication pathways in the bacterial ribosome and revealing allosteric sites/residues is critical for designing new inhibitors or repurposing readily approved drugs for this enormous machine. To shed light onto molecular details of the allosteric mechanisms, here we construct residue networks of the bacterial ribosomal complex at four different states of translation by using an effective description of the intermolecular interactions. Centrality analysis of these networks highlights the functional roles of structural components and critical residues on the ribosomal complex. High betweenness scores reveal pathways of residues connecting numerous sites on the structure. Interestingly, these pathways assemble highly conserved residues, drug binding sites, and known allosterically linked regions on the same structure. This study proposes a new residue-level model to test how distant sites on the molecular machine may be linked through hub residues that are critically located on the contact topology to inherently form communication pathways. Findings also indicate intersubunit bridges B1b, B3, B5, B7, and B8 as critical targets to design novel antibiotics.
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Affiliation(s)
- Özge Kürkçüoğlu
- Department of Chemical Engineering, Faculty of Chemical-Metallurgical Engineering, İstanbul Technical University , İstanbul , Turkey
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