1
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Seffouh A, Nikolay R, Ortega J. Critical steps in the assembly process of the bacterial 50S ribosomal subunit. Nucleic Acids Res 2024; 52:4111-4123. [PMID: 38554105 PMCID: PMC11077053 DOI: 10.1093/nar/gkae199] [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: 09/14/2023] [Revised: 03/02/2024] [Accepted: 03/07/2024] [Indexed: 04/01/2024] Open
Abstract
During assembly, ribosomal particles in bacteria fold according to energy landscapes comprised of multiple parallel pathways. Cryo-electron microscopy studies have identified a critical maturation step that occurs during the late assembly stages of the 50S subunit in Bacillus subtilis. This step acts as a point of convergency for all the parallel assembly pathways of the subunit, where an assembly intermediate accumulates in a 'locked' state, causing maturation to pause. Assembly factors then act on this critical step to 'unlock' the last maturation steps involving the functional sites. Without these factors, the 50S subunit fails to complete its assembly, causing cells to die due to a lack of functional ribosomes to synthesize proteins. In this review, we analyze these findings in B. subtilis and examine other cryo-EM studies that have visualized assembly intermediates in different bacterial species, to determine if convergency points in the ribosome assembly process are a common theme among bacteria. There are still gaps in our knowledge, as these methodologies have not yet been applied to diverse species. However, identifying and characterizing these convergency points can reveal how different bacterial species implement unique mechanisms to regulate critical steps in the ribosome assembly process.
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Affiliation(s)
- Amal Seffouh
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec H3A 0C7, Canada
- Centre for Structural Biology, McGill University, Montreal, Quebec H3G 0B1, Canada
| | - Rainer Nikolay
- Department of Genome Regulation, Max Planck Institute for Molecular Genetics, 14195 Berlin, Germany
| | - Joaquin Ortega
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec H3A 0C7, Canada
- Centre for Structural Biology, McGill University, Montreal, Quebec H3G 0B1, Canada
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2
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Fujiwara K, Tsuji N, Yoshida M, Takada H, Chiba S. Patchy and widespread distribution of bacterial translation arrest peptides associated with the protein localization machinery. Nat Commun 2024; 15:2711. [PMID: 38565864 PMCID: PMC10987492 DOI: 10.1038/s41467-024-46993-3] [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: 08/28/2023] [Accepted: 02/02/2024] [Indexed: 04/04/2024] Open
Abstract
Regulatory arrest peptides interact with specific residues on bacterial ribosomes and arrest their own translation. Here, we analyse over 30,000 bacterial genome sequences to identify additional Sec/YidC-related arrest peptides, followed by in vivo and in vitro analyses. We find that Sec/YidC-related arrest peptides show patchy, but widespread, phylogenetic distribution throughout the bacterial domain. Several of the identified peptides contain distinct conserved sequences near the C-termini, but are still able to efficiently stall bacterial ribosomes in vitro and in vivo. In addition, we identify many arrest peptides that share an R-A-P-P-like sequence, suggesting that this sequence might serve as a common evolutionary seed to overcome ribosomal structural differences across species.
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Affiliation(s)
- Keigo Fujiwara
- Faculty of Life Sciences, Kyoto Sangyo University, Motoyama, Kamigamo, Kita-Ku, Kyoto, 603-8555, Japan.
- Institute for Protein Dynamics, Kyoto Sangyo University, Kyoto, Japan.
| | - Naoko Tsuji
- Faculty of Life Sciences, Kyoto Sangyo University, Motoyama, Kamigamo, Kita-Ku, Kyoto, 603-8555, Japan
- Institute for Protein Dynamics, Kyoto Sangyo University, Kyoto, Japan
| | - Mayu Yoshida
- Faculty of Life Sciences, Kyoto Sangyo University, Motoyama, Kamigamo, Kita-Ku, Kyoto, 603-8555, Japan
- Institute for Protein Dynamics, Kyoto Sangyo University, Kyoto, Japan
| | - Hiraku Takada
- Faculty of Life Sciences, Kyoto Sangyo University, Motoyama, Kamigamo, Kita-Ku, Kyoto, 603-8555, Japan
- Institute for Protein Dynamics, Kyoto Sangyo University, Kyoto, Japan
| | - Shinobu Chiba
- Faculty of Life Sciences, Kyoto Sangyo University, Motoyama, Kamigamo, Kita-Ku, Kyoto, 603-8555, Japan.
- Institute for Protein Dynamics, Kyoto Sangyo University, Kyoto, Japan.
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3
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Morici M, Gabrielli S, Fujiwara K, Paternoga H, Beckert B, Bock LV, Chiba S, Wilson DN. RAPP-containing arrest peptides induce translational stalling by short circuiting the ribosomal peptidyltransferase activity. Nat Commun 2024; 15:2432. [PMID: 38503735 PMCID: PMC10951233 DOI: 10.1038/s41467-024-46761-3] [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: 08/30/2023] [Accepted: 01/24/2024] [Indexed: 03/21/2024] Open
Abstract
Arrest peptides containing RAPP (ArgAlaProPro) motifs have been discovered in both Gram-positive and Gram-negative bacteria, where they are thought to regulate expression of important protein localization machinery components. Here we determine cryo-EM structures of ribosomes stalled on RAPP arrest motifs in both Bacillus subtilis and Escherichia coli. Together with molecular dynamics simulations, our structures reveal that the RAPP motifs allow full accommodation of the A-site tRNA, but prevent the subsequent peptide bond from forming. Our data support a model where the RAP in the P-site interacts and stabilizes a single hydrogen atom on the Pro-tRNA in the A-site, thereby preventing an optimal geometry for the nucleophilic attack required for peptide bond formation to occur. This mechanism to short circuit the ribosomal peptidyltransferase activity is likely to operate for the majority of other RAPP-like arrest peptides found across diverse bacterial phylogenies.
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Affiliation(s)
- Martino Morici
- Institute for Biochemistry and Molecular Biology, University of Hamburg, Martin-Luther-King-Platz 6, 20146, Hamburg, Germany
| | - Sara Gabrielli
- Theoretical and Computational Biophysics Department, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Keigo Fujiwara
- Faculty of Life Sciences and Institute for Protein Dynamics, Kyoto Sangyo University, Kamigamo, Motoyama, Kita-ku, Kyoto, 603-8555, Japan
| | - Helge Paternoga
- Institute for Biochemistry and Molecular Biology, University of Hamburg, Martin-Luther-King-Platz 6, 20146, Hamburg, Germany
| | - Bertrand Beckert
- Institute for Biochemistry and Molecular Biology, University of Hamburg, Martin-Luther-King-Platz 6, 20146, Hamburg, Germany
| | - Lars V Bock
- Theoretical and Computational Biophysics Department, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Shinobu Chiba
- Faculty of Life Sciences and Institute for Protein Dynamics, Kyoto Sangyo University, Kamigamo, Motoyama, Kita-ku, Kyoto, 603-8555, Japan.
| | - Daniel N Wilson
- Institute for Biochemistry and Molecular Biology, University of Hamburg, Martin-Luther-King-Platz 6, 20146, Hamburg, Germany.
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4
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Gersteuer F, Morici M, Gabrielli S, Fujiwara K, Safdari HA, Paternoga H, Bock LV, Chiba S, Wilson DN. The SecM arrest peptide traps a pre-peptide bond formation state of the ribosome. Nat Commun 2024; 15:2431. [PMID: 38503753 PMCID: PMC10951299 DOI: 10.1038/s41467-024-46762-2] [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: 10/30/2023] [Accepted: 03/07/2024] [Indexed: 03/21/2024] Open
Abstract
Nascent polypeptide chains can induce translational stalling to regulate gene expression. This is exemplified by the E. coli secretion monitor (SecM) arrest peptide that induces translational stalling to regulate expression of the downstream encoded SecA, an ATPase that co-operates with the SecYEG translocon to facilitate insertion of proteins into or through the cytoplasmic membrane. Here we present the structure of a ribosome stalled during translation of the full-length E. coli SecM arrest peptide at 2.0 Å resolution. The structure reveals that SecM arrests translation by stabilizing the Pro-tRNA in the A-site, but in a manner that prevents peptide bond formation with the SecM-peptidyl-tRNA in the P-site. By employing molecular dynamic simulations, we also provide insight into how a pulling force on the SecM nascent chain can relieve the SecM-mediated translation arrest. Collectively, the mechanisms determined here for SecM arrest and relief are also likely to be applicable for a variety of other arrest peptides that regulate components of the protein localization machinery identified across a wide range of bacteria lineages.
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Affiliation(s)
- Felix Gersteuer
- Institute for Biochemistry and Molecular Biology, University of Hamburg, Martin-Luther-King-Platz 6, 20146, Hamburg, Germany
| | - Martino Morici
- Institute for Biochemistry and Molecular Biology, University of Hamburg, Martin-Luther-King-Platz 6, 20146, Hamburg, Germany
| | - Sara Gabrielli
- Theoretical and Computational Biophysics Department, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Keigo Fujiwara
- Faculty of Life Sciences and Institute for Protein Dynamics, Kyoto Sangyo University, Kamigamo, Motoyama, Kita-ku, Kyoto, 603-8555, Japan
| | - Haaris A Safdari
- Institute for Biochemistry and Molecular Biology, University of Hamburg, Martin-Luther-King-Platz 6, 20146, Hamburg, Germany
| | - Helge Paternoga
- Institute for Biochemistry and Molecular Biology, University of Hamburg, Martin-Luther-King-Platz 6, 20146, Hamburg, Germany
| | - Lars V Bock
- Theoretical and Computational Biophysics Department, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Shinobu Chiba
- Faculty of Life Sciences and Institute for Protein Dynamics, Kyoto Sangyo University, Kamigamo, Motoyama, Kita-ku, Kyoto, 603-8555, Japan
| | - Daniel N Wilson
- Institute for Biochemistry and Molecular Biology, University of Hamburg, Martin-Luther-King-Platz 6, 20146, Hamburg, Germany.
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5
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Svetlov MS, Dunand CF, Nakamoto JA, Atkinson GC, Safdari HA, Wilson DN, Vázquez-Laslop N, Mankin AS. Peptidyl-tRNA hydrolase is the nascent chain release factor in bacterial ribosome-associated quality control. Mol Cell 2024; 84:715-726.e5. [PMID: 38183984 DOI: 10.1016/j.molcel.2023.12.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 11/08/2023] [Accepted: 12/01/2023] [Indexed: 01/08/2024]
Abstract
Rescuing stalled ribosomes often involves their splitting into subunits. In many bacteria, the resultant large subunits bearing peptidyl-tRNAs are processed by the ribosome-associated quality control (RQC) apparatus that extends the C termini of the incomplete nascent polypeptides with polyalanine tails to facilitate their degradation. Although the tailing mechanism is well established, it is unclear how the nascent polypeptides are cleaved off the tRNAs. We show that peptidyl-tRNA hydrolase (Pth), the known role of which has been to hydrolyze ribosome-free peptidyl-tRNA, acts in concert with RQC factors to release nascent polypeptides from large ribosomal subunits. Dislodging from the ribosomal catalytic center is required for peptidyl-tRNA hydrolysis by Pth. Nascent protein folding may prevent peptidyl-tRNA retraction and interfere with the peptide release. However, oligoalanine tailing makes the peptidyl-tRNA ester bond accessible for Pth-catalyzed hydrolysis. Therefore, the oligoalanine tail serves not only as a degron but also as a facilitator of Pth-catalyzed peptidyl-tRNA hydrolysis.
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Affiliation(s)
- Maxim S Svetlov
- Center for Biomolecular Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA; Department of Pharmaceutical Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA.
| | - Clémence F Dunand
- Center for Biomolecular Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA; Department of Pharmaceutical Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Jose A Nakamoto
- Department of Experimental Medicine, University of Lund, 221 00 Lund, Sweden
| | - Gemma C Atkinson
- Department of Experimental Medicine, University of Lund, 221 00 Lund, Sweden
| | - Haaris A Safdari
- Institute for Biochemistry and Molecular Biology, University of Hamburg, 20146 Hamburg, Germany
| | - Daniel N Wilson
- Institute for Biochemistry and Molecular Biology, University of Hamburg, 20146 Hamburg, Germany
| | - Nora Vázquez-Laslop
- Center for Biomolecular Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA; Department of Pharmaceutical Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Alexander S Mankin
- Center for Biomolecular Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA; Department of Pharmaceutical Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA.
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6
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Samatova E, Komar AA, Rodnina MV. How the ribosome shapes cotranslational protein folding. Curr Opin Struct Biol 2024; 84:102740. [PMID: 38071940 DOI: 10.1016/j.sbi.2023.102740] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 11/15/2023] [Accepted: 11/16/2023] [Indexed: 02/09/2024]
Abstract
During protein synthesis, the growing nascent peptide chain moves inside the polypeptide exit tunnel of the ribosome from the peptidyl transferase center towards the exit port where it emerges into the cytoplasm. The ribosome defines the unique energy landscape of the pioneering round of protein folding. The spatial confinement and the interactions of the nascent peptide with the tunnel walls facilitate formation of secondary structures, such as α-helices. The vectorial nature of protein folding inside the tunnel favors local intra- and inter-molecular interactions, thereby inducing cotranslational folding intermediates that do not form upon protein refolding in solution. Tertiary structures start to fold in the lower part of the tunnel, where interactions with the ribosome destabilize native protein folds. The present review summarizes the recent progress in understanding the driving forces of nascent protein folding inside the tunnel and at the surface of the ribosome.
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Affiliation(s)
- Ekaterina Samatova
- Department of Physical Biochemistry, Max Planck Institute for Multidisciplinary Sciences, Goettingen 37077, Germany
| | - Anton A Komar
- Center for Gene Regulation in Health and Disease, Department of Biological, Geological and Environmental Sciences, Cleveland State University, 2121 Euclid Avenue, Cleveland, OH 44115, USA; Department of Biochemistry and Center for RNA Science and Therapeutics, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Marina V Rodnina
- Department of Physical Biochemistry, Max Planck Institute for Multidisciplinary Sciences, Goettingen 37077, Germany.
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7
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O'Reilly FJ, Graziadei A, Forbrig C, Bremenkamp R, Charles K, Lenz S, Elfmann C, Fischer L, Stülke J, Rappsilber J. Protein complexes in cells by AI-assisted structural proteomics. Mol Syst Biol 2023; 19:e11544. [PMID: 36815589 PMCID: PMC10090944 DOI: 10.15252/msb.202311544] [Citation(s) in RCA: 35] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 01/24/2023] [Accepted: 02/07/2023] [Indexed: 02/24/2023] Open
Abstract
Accurately modeling the structures of proteins and their complexes using artificial intelligence is revolutionizing molecular biology. Experimental data enable a candidate-based approach to systematically model novel protein assemblies. Here, we use a combination of in-cell crosslinking mass spectrometry and co-fractionation mass spectrometry (CoFrac-MS) to identify protein-protein interactions in the model Gram-positive bacterium Bacillus subtilis. We show that crosslinking interactions prior to cell lysis reveals protein interactions that are often lost upon cell lysis. We predict the structures of these protein interactions and others in the SubtiWiki database with AlphaFold-Multimer and, after controlling for the false-positive rate of the predictions, we propose novel structural models of 153 dimeric and 14 trimeric protein assemblies. Crosslinking MS data independently validates the AlphaFold predictions and scoring. We report and validate novel interactors of central cellular machineries that include the ribosome, RNA polymerase, and pyruvate dehydrogenase, assigning function to several uncharacterized proteins. Our approach uncovers protein-protein interactions inside intact cells, provides structural insight into their interaction interfaces, and is applicable to genetically intractable organisms, including pathogenic bacteria.
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Affiliation(s)
- Francis J O'Reilly
- Chair of BioanalyticsTechnische Universität BerlinBerlinGermany
- Present address:
Center for Structural Biology, Center for Cancer ResearchNational Cancer Institute (NCI)FrederickMDUSA
| | | | | | - Rica Bremenkamp
- Department of General Microbiology, Institute of Microbiology and GeneticsAugust‐University GöttingenGöttingenGermany
| | | | - Swantje Lenz
- Chair of BioanalyticsTechnische Universität BerlinBerlinGermany
| | - Christoph Elfmann
- Department of General Microbiology, Institute of Microbiology and GeneticsAugust‐University GöttingenGöttingenGermany
| | - Lutz Fischer
- Chair of BioanalyticsTechnische Universität BerlinBerlinGermany
| | - Jörg Stülke
- Department of General Microbiology, Institute of Microbiology and GeneticsAugust‐University GöttingenGöttingenGermany
| | - Juri Rappsilber
- Chair of BioanalyticsTechnische Universität BerlinBerlinGermany
- Wellcome Centre for Cell BiologyUniversity of EdinburghEdinburghUK
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8
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Metabolic Sensing of Extracytoplasmic Copper Availability via Translational Control by a Nascent Exported Protein. mBio 2023; 14:e0304022. [PMID: 36598193 PMCID: PMC9973294 DOI: 10.1128/mbio.03040-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Metabolic sensing is a crucial prerequisite for cells to adjust their physiology to rapidly changing environments. In bacteria, the response to intra- and extracellular ligands is primarily controlled by transcriptional regulators, which activate or repress gene expression to ensure metabolic acclimation. Translational control, such as ribosomal stalling, can also contribute to cellular acclimation and has been shown to mediate responses to changing intracellular molecules. In the current study, we demonstrate that the cotranslational export of the Rhodobacter capsulatus protein CutF regulates the translation of the downstream cutO-encoded multicopper oxidase CutO in response to extracellular copper (Cu). Our data show that CutF, acting as a Cu sensor, is cotranslationally exported by the signal recognition particle pathway. The binding of Cu to the periplasmically exposed Cu-binding motif of CutF delays its cotranslational export via its C-terminal ribosome stalling-like motif. This allows for the unfolding of an mRNA stem-loop sequence that shields the ribosome-binding site of cutO, which favors its subsequent translation. Bioinformatic analyses reveal that CutF-like proteins are widely distributed in bacteria and are often located upstream of genes involved in transition metal homeostasis. Our overall findings illustrate a highly conserved control mechanism using the cotranslational export of a protein acting as a sensor to integrate the changing availability of extracellular nutrients into metabolic acclimation. IMPORTANCE Metabolite sensing is a fundamental biological process, and the perception of dynamic changes in the extracellular environment is of paramount importance for the survival of organisms. Bacteria usually adjust their metabolisms to changing environments via transcriptional regulation. Here, using Rhodobacter capsulatus, we describe an alternative translational mechanism that controls the bacterial response to the presence of copper, a toxic micronutrient. This mechanism involves a cotranslationally secreted protein that, in the presence of copper, undergoes a process resembling ribosomal stalling. This allows for the unfolding of a downstream mRNA stem-loop and enables the translation of the adjacent Cu-detoxifying multicopper oxidase. Bioinformatic analyses reveal that such proteins are widespread, suggesting that metabolic sensing using ribosome-arrested nascent secreted proteins acting as sensors may be a common strategy for the integration of environmental signals into metabolic adaptations.
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9
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Cooper HB, Krause KL, Gardner PP. Finding priority bacterial ribosomes for future structural and antimicrobial research based upon global RNA and protein sequence analysis. PeerJ 2023; 11:e14969. [PMID: 36974140 PMCID: PMC10039652 DOI: 10.7717/peerj.14969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Accepted: 02/07/2023] [Indexed: 03/29/2023] Open
Abstract
Ribosome-targeting antibiotics comprise over half of antibiotics used in medicine, but our fundamental knowledge of their binding sites is derived primarily from ribosome structures of non-pathogenic species. These include Thermus thermophilus, Deinococcus radiodurans and the archaean Haloarcula marismortui, as well as the commensal and sometimes pathogenic organism, Escherichia coli. Advancements in electron cryomicroscopy have allowed for the determination of more ribosome structures from pathogenic bacteria, with each study highlighting species-specific differences that had not been observed in the non-pathogenic structures. These observed differences suggest that more novel ribosome structures, particularly from pathogens, are required for a more accurate understanding of the level of diversity of the entire bacterial ribosome, with the potential of leading to innovative advancements in antibiotic research. In this study, high accuracy covariance and hidden Markov models were used to annotate ribosomal RNA and protein sequences respectively from genomic sequence, allowing us to determine the underlying ribosomal sequence diversity using phylogenetic methods. This analysis provided evidence that the current non-pathogenic ribosome structures are not sufficient representatives of some pathogenic bacteria, such as Campylobacter pylori, or of whole phyla such as Bacteroidota (Bacteroidetes).
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Affiliation(s)
- Helena B. Cooper
- Department of Biochemistry, University of Otago, Dunedin, New Zealand
- Department of Infectious Diseases, Central Clinical School, Monash University, Melbourne, Victoria, Australia
| | - Kurt L. Krause
- Department of Biochemistry, University of Otago, Dunedin, New Zealand
| | - Paul P. Gardner
- Department of Biochemistry, University of Otago, Dunedin, New Zealand
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10
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Senges CHR, Warmuth HL, Vázquez-Hernández M, Uzun HD, Sagurna L, Dietze P, Schmidt C, Mücher B, Herlitze S, Krämer U, Ott I, Pomorski TG, Bandow JE. Effects of 4-Br-A23187 on Bacillus subtilis cells and unilamellar vesicles reveal it to be a potent copper ionophore. Proteomics 2022; 22:e2200061. [PMID: 35666003 PMCID: PMC10140759 DOI: 10.1002/pmic.202200061] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 05/19/2022] [Accepted: 06/03/2022] [Indexed: 11/12/2022]
Abstract
Ionophores are small molecules or peptides that transport metal ions across biological membranes. Their transport capabilities are typically characterized in vitro using vesicles and single ion species. It is difficult to infer from these data which effects ionophores have on living cells in a complex environment (e.g. culture medium), since net ion movement is influenced by many factors including ion composition of the medium, concentration gradients, pH gradient, and protein-mediated transport processes across the membrane. To gain insights into the antibacterial mechanism of action of the semisynthetic polyether ionophore 4-Br-A23187, known to efficiently transport zinc and manganese in vitro, we investigated its effects on the gram-positive model organism Bacillus subtilis. In addition to monitoring cellular ion concentrations, the physiological impact of treatment was assessed on the proteome level. 4-Br-A23187 treatment resulted in an increase in intracellular copper levels, the extent of which depended on the copper concentration of the medium. Effects of copper accumulation mirrored by the proteomic response included oxidative stress, disturbance of proteostasis, metal and sulfur homeostasis. The antibiotic effect of 4-Br-A23187 is further aggravated by a decrease in intracellular manganese and magnesium. A liposome model confirmed that 4-Br-A23187 acts as copper ionophore in vitro. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Christoph H R Senges
- Applied Microbiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, 44801, Bochum, Germany
| | - Helen L Warmuth
- Applied Microbiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, 44801, Bochum, Germany
| | - Melissa Vázquez-Hernández
- Applied Microbiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, 44801, Bochum, Germany
| | - Huriye Deniz Uzun
- Department of Molecular Biochemistry, Faculty of Chemistry and Biochemistry, Ruhr University Bochum, 44801, Bochum, Germany
| | - Leonie Sagurna
- Applied Microbiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, 44801, Bochum, Germany
| | - Pascal Dietze
- Applied Microbiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, 44801, Bochum, Germany
| | - Claudia Schmidt
- Inorganic and Organometallic Medicinal Chemistry, Faculty of Life Sciences, Technical University Braunschweig, 38106, Braunschweig, Germany.,Institute for Drug Research, Hebrew University of Jerusalem, Jerusalem, 9112001, Israel
| | - Brix Mücher
- Department of Zoology and Neurobiology, Ruhr University Bochum, 44801, Bochum, Germany
| | - Stefan Herlitze
- Department of Zoology and Neurobiology, Ruhr University Bochum, 44801, Bochum, Germany
| | - Ute Krämer
- Molecular Genetics and Physiology of Plants, Faculty of Biology and Biotechnology, Ruhr University Bochum, 44801, Bochum, Germany
| | - Ingo Ott
- Inorganic and Organometallic Medicinal Chemistry, Faculty of Life Sciences, Technical University Braunschweig, 38106, Braunschweig, Germany
| | - Thomas Günther Pomorski
- Department of Molecular Biochemistry, Faculty of Chemistry and Biochemistry, Ruhr University Bochum, 44801, Bochum, Germany
| | - Julia E Bandow
- Applied Microbiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, 44801, Bochum, Germany
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11
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Worthan SB, Franklin EA, Pham C, Yap MNF, Cruz-Vera LR. The Identity of the Constriction Region of the Ribosomal Exit Tunnel Is Important to Maintain Gene Expression in Escherichia coli. Microbiol Spectr 2022; 10:e0226121. [PMID: 35311583 PMCID: PMC9045200 DOI: 10.1128/spectrum.02261-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 02/22/2022] [Indexed: 11/23/2022] Open
Abstract
Mutational changes in bacterial ribosomes often affect gene expression and consequently cellular fitness. Understanding how mutant ribosomes disrupt global gene expression is critical to determining key genetic factors that affect bacterial survival. Here, we describe gene expression and phenotypic changes presented in Escherichia coli cells carrying an uL22(K90D) mutant ribosomal protein, which displayed alterations during growth. Ribosome profiling analyses revealed reduced expression of operons involved in catabolism, indole production, and lysine-dependent acid resistance. In general, translation initiation of proximal genes in several of these affected operons was substantially reduced. These reductions in expression were accompanied by increases in the expression of acid-induced membrane proteins and chaperones, the glutamate-decarboxylase regulon, and the autoinducer-2 metabolic regulon. In agreement with these changes, uL22(K90D) mutant cells had higher glutamate decarboxylase activity, survived better in extremely acidic conditions, and generated more biofilm in static cultures compared to their parental strain. Our work demonstrates that a single mutation in a non-conserved residue of a ribosomal protein affects a substantial number of genes to alter pH resistance and the formation of biofilms. IMPORTANCE All newly synthesized proteins must pass through a channel in the ribosome named the exit tunnel before emerging into the cytoplasm, membrane, and other compartments. The structural characteristics of the tunnel could govern protein folding and gene expression in a species-specific manner but how the identity of tunnel elements influences gene expression is less well-understood. Our global transcriptomics and translatome profiling demonstrate that a single substitution in a non-conserved amino acid of the E. coli tunnel protein uL22 has a profound impact on catabolism, cellular signaling, and acid resistance systems. Consequently, cells bearing the uL22 mutant ribosomes had an increased ability to survive acidic conditions and form biofilms. This work reveals a previously unrecognized link between tunnel identity and bacterial stress adaptation involving pH response and biofilm formation.
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Affiliation(s)
- Sarah B. Worthan
- Department of Biological Sciences, University of Alabama in Huntsville, Huntsville, Alabama, USA
| | - Elizabeth A. Franklin
- Department of Biological Sciences, University of Alabama in Huntsville, Huntsville, Alabama, USA
| | - Chi Pham
- Department of Biological Sciences, University of Alabama in Huntsville, Huntsville, Alabama, USA
| | - Mee-Ngan F. Yap
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Luis R. Cruz-Vera
- Department of Biological Sciences, University of Alabama in Huntsville, Huntsville, Alabama, USA
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12
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Cerullo F, Filbeck S, Patil PR, Hung HC, Xu H, Vornberger J, Hofer FW, Schmitt J, Kramer G, Bukau B, Hofmann K, Pfeffer S, Joazeiro CAP. Bacterial ribosome collision sensing by a MutS DNA repair ATPase paralogue. Nature 2022; 603:509-514. [PMID: 35264791 DOI: 10.1038/s41586-022-04487-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Accepted: 01/28/2022] [Indexed: 12/12/2022]
Abstract
Ribosome stalling during translation is detrimental to cellular fitness, but how this is sensed and elicits recycling of ribosomal subunits and quality control of associated mRNA and incomplete nascent chains is poorly understood1,2. Here we uncover Bacillus subtilis MutS2, a member of the conserved MutS family of ATPases that function in DNA mismatch repair3, as an unexpected ribosome-binding protein with an essential function in translational quality control. Cryo-electron microscopy analysis of affinity-purified native complexes shows that MutS2 functions in sensing collisions between stalled and translating ribosomes and suggests how ribosome collisions can serve as platforms to deploy downstream processes: MutS2 has an RNA endonuclease small MutS-related (SMR) domain, as well as an ATPase/clamp domain that is properly positioned to promote ribosomal subunit dissociation, which is a requirement both for ribosome recycling and for initiation of ribosome-associated protein quality control (RQC). Accordingly, MutS2 promotes nascent chain modification with alanine-tail degrons-an early step in RQC-in an ATPase domain-dependent manner. The relevance of these observations is underscored by evidence of strong co-occurrence of MutS2 and RQC genes across bacterial phyla. Overall, the findings demonstrate a deeply conserved role for ribosome collisions in mounting a complex response to the interruption of translation within open reading frames.
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Affiliation(s)
- Federico Cerullo
- Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Sebastian Filbeck
- Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Pratik Rajendra Patil
- Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Hao-Chih Hung
- Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Haifei Xu
- Department of Molecular Medicine, Scripps Florida, Jupiter, FL, USA
| | - Julia Vornberger
- Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Florian W Hofer
- Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Jaro Schmitt
- Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Guenter Kramer
- Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Bernd Bukau
- Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Kay Hofmann
- Institute for Genetics, University of Cologne, Cologne, Germany
| | - Stefan Pfeffer
- Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Alliance, Heidelberg, Germany.
| | - Claudio A P Joazeiro
- Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Alliance, Heidelberg, Germany. .,Department of Molecular Medicine, Scripps Florida, Jupiter, FL, USA.
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13
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Ribosome collisions induce mRNA cleavage and ribosome rescue in bacteria. Nature 2022; 603:503-508. [PMID: 35264790 DOI: 10.1038/s41586-022-04416-7] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 01/07/2022] [Indexed: 01/17/2023]
Abstract
Ribosome rescue pathways recycle stalled ribosomes and target problematic mRNAs and aborted proteins for degradation1,2. In bacteria, it remains unclear how rescue pathways distinguish ribosomes stalled in the middle of a transcript from actively translating ribosomes3-6. Here, using a genetic screen in Escherichia coli, we discovered a new rescue factor that has endonuclease activity. SmrB cleaves mRNAs upstream of stalled ribosomes, allowing the ribosome rescue factor tmRNA (which acts on truncated mRNAs3) to rescue upstream ribosomes. SmrB is recruited to ribosomes and is activated by collisions. Cryo-electron microscopy structures of collided disomes from E. coli and Bacillus subtilis show distinct and conserved arrangements of individual ribosomes and the composite SmrB-binding site. These findings reveal the underlying mechanisms by which ribosome collisions trigger ribosome rescue in bacteria.
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14
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Kolář MH, Nagy G, Kunkel J, Vaiana SM, Bock LV, Grubmüller H. Folding of VemP into translation-arresting secondary structure is driven by the ribosome exit tunnel. Nucleic Acids Res 2022; 50:2258-2269. [PMID: 35150281 PMCID: PMC8887479 DOI: 10.1093/nar/gkac038] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 11/30/2021] [Accepted: 01/25/2022] [Indexed: 01/09/2023] Open
Abstract
The ribosome is a fundamental biomolecular complex that synthesizes proteins in cells. Nascent proteins emerge from the ribosome through a tunnel, where they may interact with the tunnel walls or small molecules such as antibiotics. These interactions can cause translational arrest with notable physiological consequences. Here, we studied the arrest caused by the regulatory peptide VemP, which is known to form α-helices inside the ribosome tunnel near the peptidyl transferase center under specific conditions. We used all-atom molecular dynamics simulations of the entire ribosome and circular dichroism spectroscopy to study the driving forces of helix formation and how VemP causes the translational arrest. To that aim, we compared VemP dynamics in the ribosome tunnel with its dynamics in solution. We show that the VemP peptide has a low helical propensity in water and that the propensity is higher in mixtures of water and trifluorethanol. We propose that helix formation within the ribosome is driven by the interactions of VemP with the tunnel and that a part of VemP acts as an anchor. This anchor might slow down VemP progression through the tunnel enabling α-helix formation, which causes the elongation arrest.
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Affiliation(s)
- Michal H Kolář
- Department of Theoretical and Computational Biophysics, Max Planck Institute for Multidisciplinary Sciences, Am Fassberg 11, 370 77 Göttingen, Germany
- Department of Physical Chemistry, University of Chemistry and Technology in Prague, Technická 5, 166 28 Prague, Czech Republic
| | - Gabor Nagy
- Department of Theoretical and Computational Biophysics, Max Planck Institute for Multidisciplinary Sciences, Am Fassberg 11, 370 77 Göttingen, Germany
| | - John Kunkel
- Department of Physics and Center for Biological Physics, Arizona State University, Tempe, AZ 85287, USA
| | - Sara M Vaiana
- Department of Physics and Center for Biological Physics, Arizona State University, Tempe, AZ 85287, USA
| | - Lars V Bock
- Department of Theoretical and Computational Biophysics, Max Planck Institute for Multidisciplinary Sciences, Am Fassberg 11, 370 77 Göttingen, Germany
| | - Helmut Grubmüller
- Department of Theoretical and Computational Biophysics, Max Planck Institute for Multidisciplinary Sciences, Am Fassberg 11, 370 77 Göttingen, Germany
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15
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Inhibition of SRP-dependent protein secretion by the bacterial alarmone (p)ppGpp. Nat Commun 2022; 13:1069. [PMID: 35217658 PMCID: PMC8881573 DOI: 10.1038/s41467-022-28675-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Accepted: 02/07/2022] [Indexed: 11/08/2022] Open
Abstract
The stringent response enables bacteria to respond to nutrient limitation and other stress conditions through production of the nucleotide-based second messengers ppGpp and pppGpp, collectively known as (p)ppGpp. Here, we report that (p)ppGpp inhibits the signal recognition particle (SRP)-dependent protein targeting pathway, which is essential for membrane protein biogenesis and protein secretion. More specifically, (p)ppGpp binds to the SRP GTPases Ffh and FtsY, and inhibits the formation of the SRP receptor-targeting complex, which is central for the coordinated binding of the translating ribosome to the SecYEG translocon. Cryo-EM analysis of SRP bound to translating ribosomes suggests that (p)ppGpp may induce a distinct conformational stabilization of the NG domain of Ffh and FtsY in Bacillus subtilis but not in E. coli. Bacterial responses to nutrient limitation and other stress conditions are often modulated by the nucleotide-based second messenger (p)ppGpp. Here, the authors show that (p)ppGpp inhibits the SRP membrane-protein insertion and secretion pathway by binding to GTPases Ffh and FtsY.
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16
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Seffouh A, Trahan C, Wasi T, Jain N, Basu K, Britton RA, Oeffinger M, Ortega J. RbgA ensures the correct timing in the maturation of the 50S subunits functional sites. Nucleic Acids Res 2022; 50:10801-10816. [PMID: 35141754 PMCID: PMC9638911 DOI: 10.1093/nar/gkac059] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2021] [Revised: 01/15/2022] [Accepted: 01/26/2022] [Indexed: 11/26/2022] Open
Abstract
RbgA is an essential protein for the assembly of the 50S subunit in Bacillus subtilis. Depletion of RbgA leads to the accumulation of the 45S intermediate. A strain expressing a RbgA variant with reduced GTPase activity generates spontaneous suppressor mutations in uL6. Each suppressor strain accumulates a unique 44S intermediate. We reasoned that characterizing the structure of these mutant 44S intermediates may explain why RbgA is required to catalyze the folding of the 50S functional sites. We found that in the 44S particles, rRNA helices H42 and H97, near the binding site of uL6, adopt a flexible conformation and allow the central protuberance and functional sites in the mutant 44S particles to mature in any order. Instead, the wild-type 45S particles exhibit a stable H42-H97 interaction and their functional sites always mature last. The dependence on RbgA was also less pronounced in the 44S particles. We concluded that the binding of uL6 pauses the maturation of the functional sites, but the central protuberance continues to fold. RbgA exclusively binds intermediates with a formed central protuberance and licenses the folding of the functional sites. Through this mechanism, RbgA ensures that the functional sites of the 50S mature last.
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Affiliation(s)
- Amal Seffouh
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec H3A 0C7, Canada.,Centre for Structural Biology, McGill University, Montreal, Quebec H3G 0B1, Canada
| | - Chirstian Trahan
- Center for genetic and neurological diseases, Institut de Recherches Cliniques de Montréal (IRCM), Montréal, Quebec H2W 1R7, Canada
| | - Tanzila Wasi
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec H3A 0C7, Canada.,Centre for Structural Biology, McGill University, Montreal, Quebec H3G 0B1, Canada
| | - Nikhil Jain
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA.,Center for Metagenomics and Microbiome Research, Baylor College of Medicine, Houston, TX 77030, USA
| | - Kaustuv Basu
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec H3A 0C7, Canada.,Centre for Structural Biology, McGill University, Montreal, Quebec H3G 0B1, Canada
| | - Robert A Britton
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA.,Center for Metagenomics and Microbiome Research, Baylor College of Medicine, Houston, TX 77030, USA
| | - Marlene Oeffinger
- Center for genetic and neurological diseases, Institut de Recherches Cliniques de Montréal (IRCM), Montréal, Quebec H2W 1R7, Canada.,Département de Biochimie et Médecine Moléculaire, Université de Montréal, Montréal, Quebec H3T 1J4, Canada.,Division of Experimental Medicine, McGill University, Montréal, Quebec H4A 3J1, Canada
| | - Joaquin Ortega
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec H3A 0C7, Canada.,Centre for Structural Biology, McGill University, Montreal, Quebec H3G 0B1, Canada
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17
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Sattler L, Graumann PL. Real-Time Messenger RNA Dynamics in Bacillus subtilis. Front Microbiol 2021; 12:760857. [PMID: 34867890 PMCID: PMC8637298 DOI: 10.3389/fmicb.2021.760857] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Accepted: 10/08/2021] [Indexed: 11/13/2022] Open
Abstract
Messenger RNA molecules have been localized to different positions in cells and have been followed by time-lapse microscopy. We have used MS2-mVenus-labeled mRNA and single-particle tracking to obtain information on the dynamics of single-mRNA molecules in real time. Using single-molecule tracking, we show that several mRNA molecules visualized via two MS2-binding sites and MS2-mVenus expressed in Bacillus subtilis cells show free diffusion through the entire cell and constrained motion predominantly close to the cell membrane and at the polar regions of the cells. Because constrained motion of mRNAs likely reflects molecules complexed with ribosomes, our data support the idea that translation occurs at sites surrounding the nucleoids. Squared displacement analyses show the existence of at least two distinct populations of molecules with different diffusion constants or possibly of three populations, for example, freely mobile mRNAs, mRNAs in transition complexes, or in complex with polysomes. Diffusion constants between differently sized mRNAs did not differ dramatically and were much lower than that of cytosolic proteins. These data agree with the large size of mRNA molecules and suggest that, within the viscous cytoplasm, size variations do not translate into mobility differences. However, at observed diffusion constants, mRNA molecules would be able to reach all positions within cells in a frame of seconds. We did not observe strong differences in the location of confined motion for mRNAs encoding mostly soluble or membrane proteins, indicating that there is no strong bias for localization of membrane protein-encoding transcripts for the cell membrane.
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Affiliation(s)
- Laura Sattler
- Centre for Synthetic Microbiology (SYNMIKRO) and Fachbereich Chemie, Philipps-Universität Marburg, Marburg, Germany
| | - Peter L Graumann
- Centre for Synthetic Microbiology (SYNMIKRO) and Fachbereich Chemie, Philipps-Universität Marburg, Marburg, Germany
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18
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Chadani Y, Sugata N, Niwa T, Ito Y, Iwasaki S, Taguchi H. Nascent polypeptide within the exit tunnel stabilizes the ribosome to counteract risky translation. EMBO J 2021; 40:e108299. [PMID: 34672004 PMCID: PMC8634131 DOI: 10.15252/embj.2021108299] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 09/21/2021] [Accepted: 09/29/2021] [Indexed: 01/26/2023] Open
Abstract
Continuous translation elongation, irrespective of amino acid sequences, is a prerequisite for living organisms to produce their proteomes. However, nascent polypeptide products bear an inherent risk of elongation abortion. For example, negatively charged sequences with occasional intermittent prolines, termed intrinsic ribosome destabilization (IRD) sequences, weaken the translating ribosomal complex, causing certain nascent chain sequences to prematurely terminate translation. Here, we show that most potential IRD sequences in the middle of open reading frames remain cryptic and do not interrupt translation, due to two features of the nascent polypeptide. Firstly, the nascent polypeptide itself spans the exit tunnel, and secondly, its bulky amino acid residues occupy the tunnel entrance region, thereby serving as a bridge and protecting the large and small ribosomal subunits from dissociation. Thus, nascent polypeptide products have an inbuilt ability to ensure elongation continuity.
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Affiliation(s)
- Yuhei Chadani
- Cell Biology CenterInstitute of Innovative ResearchTokyo Institute of TechnologyYokohamaJapan
| | - Nobuyuki Sugata
- School of Life Science and TechnologyTokyo Institute of TechnologyYokohamaJapan
| | - Tatsuya Niwa
- Cell Biology CenterInstitute of Innovative ResearchTokyo Institute of TechnologyYokohamaJapan
- School of Life Science and TechnologyTokyo Institute of TechnologyYokohamaJapan
| | - Yosuke Ito
- School of Life Science and TechnologyTokyo Institute of TechnologyYokohamaJapan
| | - Shintaro Iwasaki
- RNA Systems Biochemistry LaboratoryRIKEN Cluster for Pioneering ResearchSaitamaJapan
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier SciencesThe University of TokyoKashiwaJapan
| | - Hideki Taguchi
- Cell Biology CenterInstitute of Innovative ResearchTokyo Institute of TechnologyYokohamaJapan
- School of Life Science and TechnologyTokyo Institute of TechnologyYokohamaJapan
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19
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Shatoff EA, Gemler BT, Bundschuh R, Fredrick K. Maturation of 23S rRNA includes removal of helix H1 in many bacteria. RNA Biol 2021; 18:856-865. [PMID: 34812116 PMCID: PMC8782170 DOI: 10.1080/15476286.2021.2000793] [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: 11/17/2022] Open
Abstract
In most bacteria, the three ribosomal RNAs (rRNAs) are encoded together in each of several near-identical operons. As soon as the nascent precursor rRNA emerges from RNA polymerase, ribosome assembly begins. This process entails ribosomal protein binding, rRNA folding, rRNA modification, and rRNA processing. In the model organisms Escherichia coli and Bacillus subtilis, rRNA processing results in similar mature rRNAs, despite substantial differences in the cohort of RNAses involved. A recent study of Flavobacterium johnsoniae, a member of the phylum Bacteroidota (formerly Bacteroidetes), revealed that helix H1 of 23S rRNA is absent from ribosomes, apparently a consequence of rRNA maturation. In this work, we mined RNA-seq data from 19 individual organisms and ocean metatranscriptomic samples to compare rRNA processing across diverse bacterial lineages. We found that mature ribosomes from multiple clades lack H1, and typically these ribosomes also lack an encoded H98. For all groups analysed, H1 is predicted to form in precursor rRNA as part of a longer leader-trailer helix. Hence, we infer that evolutionary loss of H98 sets the stage for H1 removal during 50S subunit maturation.
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Affiliation(s)
- Elan A Shatoff
- Department of Physics, The Ohio State University, Columbus, OH, USA.,Center for RNA Biology, The Ohio State University, Columbus, OH, USA
| | - Bryan T Gemler
- Center for RNA Biology, The Ohio State University, Columbus, OH, USA.,Interdisciplinary Biophysics Graduate Program, The Ohio State University, Columbus, OH, USA
| | - Ralf Bundschuh
- Department of Physics, The Ohio State University, Columbus, OH, USA.,Center for RNA Biology, The Ohio State University, Columbus, OH, USA.,Interdisciplinary Biophysics Graduate Program, The Ohio State University, Columbus, OH, USA.,Department of Chemistry & Biochemistry, The Ohio State University, Columbus, OH, USA.,Division of Hematology, Department of Internal Medicine, The Ohio State University, Columbus, OH, USA
| | - Kurt Fredrick
- Center for RNA Biology, The Ohio State University, Columbus, OH, USA.,Department of Microbiology, The Ohio State University, Columbus, OH, USA
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20
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Structural basis for the tryptophan sensitivity of TnaC-mediated ribosome stalling. Nat Commun 2021; 12:5340. [PMID: 34504068 PMCID: PMC8429421 DOI: 10.1038/s41467-021-25663-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Accepted: 08/24/2021] [Indexed: 02/07/2023] Open
Abstract
Free L-tryptophan (L-Trp) stalls ribosomes engaged in the synthesis of TnaC, a leader peptide controlling the expression of the Escherichia coli tryptophanase operon. Despite extensive characterization, the molecular mechanism underlying the recognition and response to L-Trp by the TnaC-ribosome complex remains unknown. Here, we use a combined biochemical and structural approach to characterize a TnaC variant (R23F) with greatly enhanced sensitivity for L-Trp. We show that the TnaC-ribosome complex captures a single L-Trp molecule to undergo termination arrest and that nascent TnaC prevents the catalytic GGQ loop of release factor 2 from adopting an active conformation at the peptidyl transferase center. Importantly, the L-Trp binding site is not altered by the R23F mutation, suggesting that the relative rates of L-Trp binding and peptidyl-tRNA cleavage determine the tryptophan sensitivity of each variant. Thus, our study reveals a strategy whereby a nascent peptide assists the ribosome in detecting a small metabolite.
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21
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Lucas BA, Himes BA, Xue L, Grant T, Mahamid J, Grigorieff N. Locating macromolecular assemblies in cells by 2D template matching with cisTEM. eLife 2021; 10:e68946. [PMID: 34114559 PMCID: PMC8219381 DOI: 10.7554/elife.68946] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 06/09/2021] [Indexed: 12/31/2022] Open
Abstract
For a more complete understanding of molecular mechanisms, it is important to study macromolecules and their assemblies in the broader context of the cell. This context can be visualized at nanometer resolution in three dimensions (3D) using electron cryo-tomography, which requires tilt series to be recorded and computationally aligned, currently limiting throughput. Additionally, the high-resolution signal preserved in the raw tomograms is currently limited by a number of technical difficulties, leading to an increased false-positive detection rate when using 3D template matching to find molecular complexes in tomograms. We have recently described a 2D template matching approach that addresses these issues by including high-resolution signal preserved in single-tilt images. A current limitation of this approach is the high computational cost that limits throughput. We describe here a GPU-accelerated implementation of 2D template matching in the image processing software cisTEM that allows for easy scaling and improves the accessibility of this approach. We apply 2D template matching to identify ribosomes in images of frozen-hydrated Mycoplasma pneumoniae cells with high precision and sensitivity, demonstrating that this is a versatile tool for in situ visual proteomics and in situ structure determination. We benchmark the results with 3D template matching of tomograms acquired on identical sample locations and identify strengths and weaknesses of both techniques, which offer complementary information about target localization and identity.
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Affiliation(s)
- Bronwyn A Lucas
- Howard Hughes Medical Institute, Janelia Research CampusAshburnUnited States
| | - Benjamin A Himes
- Howard Hughes Medical Institute, RNA Therapeutics Institute, The University of Massachusetts Medical SchoolWorcesterUnited States
| | - Liang Xue
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL)HeidelbergGermany
- Collaboration for joint PhD degree between EMBL and Heidelberg University, Faculty of BiosciencesHeidelbergGermany
| | - Timothy Grant
- Howard Hughes Medical Institute, Janelia Research CampusAshburnUnited States
| | - Julia Mahamid
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL)HeidelbergGermany
| | - Nikolaus Grigorieff
- Howard Hughes Medical Institute, RNA Therapeutics Institute, The University of Massachusetts Medical SchoolWorcesterUnited States
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22
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Pausch P, Abdelshahid M, Steinchen W, Schäfer H, Gratani FL, Freibert SA, Wolz C, Turgay K, Wilson DN, Bange G. Structural Basis for Regulation of the Opposing (p)ppGpp Synthetase and Hydrolase within the Stringent Response Orchestrator Rel. Cell Rep 2021; 32:108157. [PMID: 32937119 DOI: 10.1016/j.celrep.2020.108157] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 07/10/2020] [Accepted: 08/26/2020] [Indexed: 12/12/2022] Open
Abstract
The stringent response enables metabolic adaptation of bacteria under stress conditions and is governed by RelA/SpoT Homolog (RSH)-type enzymes. Long RSH-type enzymes encompass an N-terminal domain (NTD) harboring the second messenger nucleotide (p)ppGpp hydrolase and synthetase activity and a stress-perceiving and regulatory C-terminal domain (CTD). CTD-mediated binding of Rel to stalled ribosomes boosts (p)ppGpp synthesis. However, how the opposing activities of the NTD are controlled in the absence of stress was poorly understood. Here, we demonstrate on the RSH-type protein Rel that the critical regulative elements reside within the TGS (ThrRS, GTPase, and SpoT) subdomain of the CTD, which associates to and represses the synthetase to concomitantly allow for activation of the hydrolase. Furthermore, we show that Rel forms homodimers, which appear to control the interaction with deacylated-tRNA, but not the enzymatic activity of Rel. Collectively, our study provides a detailed molecular view into the mechanism of stringent response repression in the absence of stress.
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Affiliation(s)
- Patrick Pausch
- Center for Synthetic Microbiology & Department of Chemistry, Hans-Meerwein-Strasse, C07, Philipps-University Marburg, 35043 Marburg, Germany
| | - Maha Abdelshahid
- Institute for Biochemistry and Molecular Biology, University of Hamburg, 20146 Hamburg, Germany
| | - Wieland Steinchen
- Center for Synthetic Microbiology & Department of Chemistry, Hans-Meerwein-Strasse, C07, Philipps-University Marburg, 35043 Marburg, Germany
| | - Heinrich Schäfer
- Leibniz University of Hannover, Institute for Microbiology & Max Planck Unit for the Science of Pathogens, Charitéplatz 1, 10117 Berlin, Germany
| | - Fabio Lino Gratani
- Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen, 72076 Tübingen, Germany
| | - Sven-Andreas Freibert
- Center for Synthetic Microbiology & Institute for Cytobiology and Cytopathology, Philipps-University Marburg, 35043 Marburg, Germany
| | - Christiane Wolz
- Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen, 72076 Tübingen, Germany
| | - Kürşad Turgay
- Leibniz University of Hannover, Institute for Microbiology & Max Planck Unit for the Science of Pathogens, Charitéplatz 1, 10117 Berlin, Germany.
| | - Daniel N Wilson
- Institute for Biochemistry and Molecular Biology, University of Hamburg, 20146 Hamburg, Germany.
| | - Gert Bange
- Center for Synthetic Microbiology & Department of Chemistry, Hans-Meerwein-Strasse, C07, Philipps-University Marburg, 35043 Marburg, Germany.
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23
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Zimmer MH, Niesen MJM, Miller TF. Force transduction creates long-ranged coupling in ribosomes stalled by arrest peptides. Biophys J 2021; 120:2425-2435. [PMID: 33932440 DOI: 10.1016/j.bpj.2021.03.041] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 03/09/2021] [Accepted: 03/19/2021] [Indexed: 11/16/2022] Open
Abstract
Force-sensitive arrest peptides regulate protein biosynthesis by stalling the ribosome as they are translated. Synthesis can be resumed when the nascent arrest peptide experiences a pulling force of sufficient magnitude to break the stall. Efficient stalling is dependent on the specific identity of a large number of amino acids, including amino acids that are tens of angstroms away from the peptidyl transferase center (PTC). The mechanism of force-induced restart and the role of these essential amino acids far from the PTC is currently unknown. We use hundreds of independent molecular dynamics trajectories spanning over 120 μs in combination with kinetic analysis to characterize multiple barriers along the force-induced restart pathway for the arrest peptide SecM. We find that the essential amino acids far from the PTC play a major role in controlling the transduction of applied force. In successive states along the stall-breaking pathway, the applied force propagates up the nascent chain until it reaches the C-terminus of SecM and the PTC, inducing conformational changes that allow for restart of translation. A similar mechanism of force propagation through multiple states is observed in the VemP stall-breaking pathway, but secondary structure in VemP allows for heterogeneity in the order of transitions through intermediate states. Results from both arrest peptides explain how residues that are tens of angstroms away from the catalytic center of the ribosome impact stalling efficiency by mediating the response to an applied force and shielding the amino acids responsible for maintaining the stalled state of the PTC.
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Affiliation(s)
- Matthew H Zimmer
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California
| | - Michiel J M Niesen
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California
| | - Thomas F Miller
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California.
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24
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Akanuma G. Diverse relationships between metal ions and the ribosome. Biosci Biotechnol Biochem 2021; 85:1582-1593. [PMID: 33877305 DOI: 10.1093/bbb/zbab070] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Accepted: 03/30/2021] [Indexed: 11/12/2022]
Abstract
The ribosome requires metal ions for structural stability and translational activity. These metal ions are important for stabilizing the secondary structure of ribosomal RNA, binding of ribosomal proteins to the ribosome, and for interaction of ribosomal subunits. In this review, various relationships between ribosomes and metal ions, especially Mg2+ and Zn2+, are presented. Mg2+ regulates gene expression by modulating the translational stability and synthesis of ribosomes, which in turn contribute to the cellular homeostasis of Mg2+. In addition, Mg2+ can partly complement the function of ribosomal proteins. Conversely, a reduction in the cellular concentration of Zn2+ induces replacement of ribosomal proteins, which mobilizes free-Zn2+ in the cell and represses translation activity. Evolutional relationships between these metal ions and the ribosome are also discussed.
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Affiliation(s)
- Genki Akanuma
- Department of Life Science, Graduate School of Science, Gakushuin University, Toshima-ku, Tokyo, Japan.,Department of Life Science, College of Science, Rikkyo University, Toshima-ku, Tokyo, Japan
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25
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Müller C, Crowe-McAuliffe C, Wilson DN. Ribosome Rescue Pathways in Bacteria. Front Microbiol 2021; 12:652980. [PMID: 33815344 PMCID: PMC8012679 DOI: 10.3389/fmicb.2021.652980] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 02/23/2021] [Indexed: 12/18/2022] Open
Abstract
Ribosomes that become stalled on truncated or damaged mRNAs during protein synthesis must be rescued for the cell to survive. Bacteria have evolved a diverse array of rescue pathways to remove the stalled ribosomes from the aberrant mRNA and return them to the free pool of actively translating ribosomes. In addition, some of these pathways target the damaged mRNA and the incomplete nascent polypeptide chain for degradation. This review highlights the recent developments in our mechanistic understanding of bacterial ribosomal rescue systems, including drop-off, trans-translation mediated by transfer-messenger RNA and small protein B, ribosome rescue by the alternative rescue factors ArfA and ArfB, as well as Bacillus ribosome rescue factor A, an additional rescue system found in some Gram-positive bacteria, such as Bacillus subtilis. Finally, we discuss the recent findings of ribosome-associated quality control in particular bacterial lineages mediated by RqcH and RqcP. The importance of rescue pathways for bacterial survival suggests they may represent novel targets for the development of new antimicrobial agents against multi-drug resistant pathogenic bacteria.
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Affiliation(s)
| | | | - Daniel N. Wilson
- Institute for Biochemistry and Molecular Biology, University of Hamburg, Hamburg, Germany
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26
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Sakiyama K, Shimokawa-Chiba N, Fujiwara K, Chiba S. Search for translation arrest peptides encoded upstream of genes for components of protein localization pathways. Nucleic Acids Res 2021; 49:1550-1566. [PMID: 33503266 PMCID: PMC7897499 DOI: 10.1093/nar/gkab024] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Revised: 01/05/2021] [Accepted: 01/08/2021] [Indexed: 02/06/2023] Open
Abstract
Regulatory nascent peptides participate in the regulation of cellular functions by the mechanisms involving regulated translation arrest. A class of them in bacteria, called monitoring substrates, feedback-regulates the expression of a specific component of protein localization machinery. Three monitoring substrates, SecM, MifM and VemP have previously been identified. Here, we attempt at identifying additional arrest peptides in bacteria. Our bioinformatic searches over more than 400 bacterial genomic sequences for proteins that have the common characteristic features shared by the known monitoring substrates and subsequent in vitro and in vivo characterization of the highlighted sequences allowed the identification of three arrest peptides termed ApcA, ApdA and ApdP. ApcA and ApdA homologs are conserved among a subset of actinobacteria, whereas ApdP has homologs in a subset of α-proteobacteria. We demonstrate that these arrest peptides, in their ribosome-tethered nascent states, inhibit peptidyl transfer. The elongation arrest occurs at a specific codon near the 3′ end of the coding region, in a manner depending on the amino acid sequence of the nascent chain. Interestingly, the arrest sequences of ApcA, ApdA and ApdP share a sequence R-A-P-G/P that is essential for the elongation arrest.
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Affiliation(s)
- Karen Sakiyama
- Faculty of Life Sciences, Kyoto Sangyo University, Motoyama, Kamigamo, Kita-Ku, Kyoto 603-8555, Japan
| | - Naomi Shimokawa-Chiba
- Faculty of Life Sciences, Kyoto Sangyo University, Motoyama, Kamigamo, Kita-Ku, Kyoto 603-8555, Japan.,Institute for Protein Dynamics, Kyoto Sangyo University, Japan
| | - Keigo Fujiwara
- Faculty of Life Sciences, Kyoto Sangyo University, Motoyama, Kamigamo, Kita-Ku, Kyoto 603-8555, Japan.,Institute for Protein Dynamics, Kyoto Sangyo University, Japan
| | - Shinobu Chiba
- Faculty of Life Sciences, Kyoto Sangyo University, Motoyama, Kamigamo, Kita-Ku, Kyoto 603-8555, Japan.,Institute for Protein Dynamics, Kyoto Sangyo University, Japan
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27
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Jha V, Roy B, Jahagirdar D, McNutt ZA, Shatoff EA, Boleratz BL, Watkins DE, Bundschuh R, Basu K, Ortega J, Fredrick K. Structural basis of sequestration of the anti-Shine-Dalgarno sequence in the Bacteroidetes ribosome. Nucleic Acids Res 2021; 49:547-567. [PMID: 33330920 PMCID: PMC7797042 DOI: 10.1093/nar/gkaa1195] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Revised: 11/18/2020] [Accepted: 11/24/2020] [Indexed: 11/25/2022] Open
Abstract
Genomic studies have indicated that certain bacterial lineages such as the Bacteroidetes lack Shine-Dalgarno (SD) sequences, and yet with few exceptions ribosomes of these organisms carry the canonical anti-SD (ASD) sequence. Here, we show that ribosomes purified from Flavobacterium johnsoniae, a representative of the Bacteroidetes, fail to recognize the SD sequence of mRNA in vitro. A cryo-electron microscopy structure of the complete 70S ribosome from F. johnsoniae at 2.8 Å resolution reveals that the ASD is sequestered by ribosomal proteins bS21, bS18 and bS6, explaining the basis of ASD inhibition. The structure also uncovers a novel ribosomal protein—bL38. Remarkably, in F. johnsoniae and many other Flavobacteriia, the gene encoding bS21 contains a strong SD, unlike virtually all other genes. A subset of Flavobacteriia have an alternative ASD, and in these organisms the fully complementary sequence lies upstream of the bS21 gene, indicative of natural covariation. In other Bacteroidetes classes, strong SDs are frequently found upstream of the genes for bS21 and/or bS18. We propose that these SDs are used as regulatory elements, enabling bS21 and bS18 to translationally control their own production.
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Affiliation(s)
- Vikash Jha
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec H3A 0C7, Canada.,Centre for Structural Biology, McGill University, Montreal, Quebec H3G 0B1, Canada
| | - Bappaditya Roy
- Department of Microbiology, The Ohio State University, Columbus, OH 43210, USA.,Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA
| | - Dushyant Jahagirdar
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec H3A 0C7, Canada.,Centre for Structural Biology, McGill University, Montreal, Quebec H3G 0B1, Canada
| | - Zakkary A McNutt
- Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA.,Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, USA
| | - Elan A Shatoff
- Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA.,Department of Physics, The Ohio State University, Columbus, OH 43210, USA
| | - Bethany L Boleratz
- Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, USA
| | - Dean E Watkins
- Department of Microbiology, The Ohio State University, Columbus, OH 43210, USA
| | - Ralf Bundschuh
- Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA.,Department of Physics, The Ohio State University, Columbus, OH 43210, USA.,Department of Chemistry & Biochemistry, Division of Hematology, The Ohio State University, Columbus, OH 43210, USA
| | - Kaustuv Basu
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec H3A 0C7, Canada.,Centre for Structural Biology, McGill University, Montreal, Quebec H3G 0B1, Canada
| | - Joaquin Ortega
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec H3A 0C7, Canada.,Centre for Structural Biology, McGill University, Montreal, Quebec H3G 0B1, Canada
| | - Kurt Fredrick
- Department of Microbiology, The Ohio State University, Columbus, OH 43210, USA.,Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA.,Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, USA
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28
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Filbeck S, Cerullo F, Paternoga H, Tsaprailis G, Joazeiro CAP, Pfeffer S. Mimicry of Canonical Translation Elongation Underlies Alanine Tail Synthesis in RQC. Mol Cell 2020; 81:104-114.e6. [PMID: 33259811 DOI: 10.1016/j.molcel.2020.11.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 10/06/2020] [Accepted: 10/29/2020] [Indexed: 12/21/2022]
Abstract
Aborted translation produces large ribosomal subunits obstructed with tRNA-linked nascent chains, which are substrates of ribosome-associated quality control (RQC). Bacterial RqcH, a widely conserved RQC factor, senses the obstruction and recruits tRNAAla(UGC) to modify nascent-chain C termini with a polyalanine degron. However, how RqcH and its eukaryotic homologs (Rqc2 and NEMF), despite their relatively simple architecture, synthesize such C-terminal tails in the absence of a small ribosomal subunit and mRNA has remained unknown. Here, we present cryoelectron microscopy (cryo-EM) structures of Bacillus subtilis RQC complexes representing different Ala tail synthesis steps. The structures explain how tRNAAla is selected via anticodon reading during recruitment to the A-site and uncover striking hinge-like movements in RqcH leading tRNAAla into a hybrid A/P-state associated with peptidyl-transfer. Finally, we provide structural, biochemical, and molecular genetic evidence identifying the Hsp15 homolog (encoded by rqcP) as a novel RQC component that completes the cycle by stabilizing the P-site tRNA conformation. Ala tailing thus follows mechanistic principles surprisingly similar to canonical translation elongation.
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Affiliation(s)
- Sebastian Filbeck
- Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, 69120 Heidelberg, Germany
| | - Federico Cerullo
- Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, 69120 Heidelberg, Germany
| | - Helge Paternoga
- Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, 69120 Heidelberg, Germany
| | | | - Claudio A P Joazeiro
- Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, 69120 Heidelberg, Germany; Department of Molecular Medicine, Scripps Research, Jupiter, FL 33458, USA.
| | - Stefan Pfeffer
- Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, 69120 Heidelberg, Germany.
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29
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Phillips BP, Miller EA. Ribosome-associated quality control of membrane proteins at the endoplasmic reticulum. J Cell Sci 2020; 133:133/22/jcs251983. [PMID: 33247003 PMCID: PMC7116877 DOI: 10.1242/jcs.251983] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Protein synthesis is an energetically costly, complex and risky process. Aberrant protein biogenesis can result in cellular toxicity and disease, with membrane-embedded proteins being particularly challenging for the cell. In order to protect the cell from consequences of defects in membrane proteins, quality control systems act to maintain protein homeostasis. The majority of these pathways act post-translationally; however, recent evidence reveals that membrane proteins are also subject to co-translational quality control during their synthesis in the endoplasmic reticulum (ER). This newly identified quality control pathway employs components of the cytosolic ribosome-associated quality control (RQC) machinery but differs from canonical RQC in that it responds to biogenesis state of the substrate rather than mRNA aberrations. This ER-associated RQC (ER-RQC) is sensitive to membrane protein misfolding and malfunctions in the ER insertion machinery. In this Review, we discuss the advantages of co-translational quality control of membrane proteins, as well as potential mechanisms of substrate recognition and degradation. Finally, we discuss some outstanding questions concerning future studies of ER-RQC of membrane proteins.
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Affiliation(s)
- Ben P Phillips
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
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30
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Wang M, Yu H, Li X, Shen Z. Single-gene regulated non-spore-forming Bacillus subtilis: Construction, transcriptome responses, and applications for producing enzymes and surfactin. Metab Eng 2020; 62:235-248. [DOI: 10.1016/j.ymben.2020.08.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Revised: 08/12/2020] [Accepted: 08/12/2020] [Indexed: 01/01/2023]
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31
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Jednačak T, Mikulandra I, Novak P. Advanced Methods for Studying Structure and Interactions of Macrolide Antibiotics. Int J Mol Sci 2020; 21:E7799. [PMID: 33096889 PMCID: PMC7589898 DOI: 10.3390/ijms21207799] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2020] [Revised: 10/09/2020] [Accepted: 10/19/2020] [Indexed: 11/17/2022] Open
Abstract
Macrolide antibiotics are macrocyclic compounds that are clinically used and prescribed for the treatment of upper and lower respiratory tract infections. They inhibit the synthesis of bacterial proteins by reversible binding to the 23S rRNA at or near the peptidyl transferase center. However, their excellent antibacterial profile was largely compromised by the emergence of bacterial resistance. Today, fighting resistance to antibiotics is one of the greatest challenges in medicinal chemistry. Considering various physicochemical properties of macrolides, understanding their structure and interactions with macromolecular targets is crucial for the design of new antibiotics efficient against resistant pathogens. The solid-state structures of some macrolide-ribosome complexes have recently been solved, throwing new light on the macrolide binding mechanisms. On the other hand, a combination of NMR spectroscopy and molecular modeling calculations can be applied to study free and bound conformations in solution. In this article, a description of advanced physicochemical methods for elucidating the structure and interactions of macrolide antibiotics in solid state and solution will be provided, and their principal advantages and drawbacks will be discussed.
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Affiliation(s)
- Tomislav Jednačak
- Department of Chemistry, Faculty of Science, University of Zagreb, Horvatovac 102a, HR-10000 Zagreb, Croatia;
| | | | - Predrag Novak
- Department of Chemistry, Faculty of Science, University of Zagreb, Horvatovac 102a, HR-10000 Zagreb, Croatia;
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32
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Fujiwara K, Katagi Y, Ito K, Chiba S. Proteome-wide Capture of Co-translational Protein Dynamics in Bacillus subtilis Using TnDR, a Transposable Protein-Dynamics Reporter. Cell Rep 2020; 33:108250. [DOI: 10.1016/j.celrep.2020.108250] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 09/03/2020] [Accepted: 09/17/2020] [Indexed: 11/29/2022] Open
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33
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O'Reilly FJ, Xue L, Graziadei A, Sinn L, Lenz S, Tegunov D, Blötz C, Singh N, Hagen WJH, Cramer P, Stülke J, Mahamid J, Rappsilber J. In-cell architecture of an actively transcribing-translating expressome. Science 2020; 369:554-557. [PMID: 32732422 DOI: 10.1126/science.abb3758] [Citation(s) in RCA: 154] [Impact Index Per Article: 38.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Accepted: 06/01/2020] [Indexed: 12/18/2022]
Abstract
Structural biology studies performed inside cells can capture molecular machines in action within their native context. In this work, we developed an integrative in-cell structural approach using the genome-reduced human pathogen Mycoplasma pneumoniae We combined whole-cell cross-linking mass spectrometry, cellular cryo-electron tomography, and integrative modeling to determine an in-cell architecture of a transcribing and translating expressome at subnanometer resolution. The expressome comprises RNA polymerase (RNAP), the ribosome, and the transcription elongation factors NusG and NusA. We pinpointed NusA at the interface between a NusG-bound elongating RNAP and the ribosome and propose that it can mediate transcription-translation coupling. Translation inhibition dissociated the expressome, whereas transcription inhibition stalled and rearranged it. Thus, the active expressome architecture requires both translation and transcription elongation within the cell.
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Affiliation(s)
- Francis J O'Reilly
- Bioanalytics Unit, Institute of Biotechnology, Technische Universität Berlin, 13355 Berlin, Germany
| | - Liang Xue
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany.,Collaboration for joint PhD degree between EMBL and Heidelberg University, Faculty of Biosciences, 69120 Heidelberg, Germany
| | - Andrea Graziadei
- Bioanalytics Unit, Institute of Biotechnology, Technische Universität Berlin, 13355 Berlin, Germany
| | - Ludwig Sinn
- Bioanalytics Unit, Institute of Biotechnology, Technische Universität Berlin, 13355 Berlin, Germany
| | - Swantje Lenz
- Bioanalytics Unit, Institute of Biotechnology, Technische Universität Berlin, 13355 Berlin, Germany
| | - Dimitry Tegunov
- Department of Molecular Biology, Max-Planck-Institute for Biophysical Chemistry, 37077 Göttingen, Germany
| | - Cedric Blötz
- Department of General Microbiology, Institute of Microbiology and Genetics, GZMB, Georg-August-University Göttingen, 37077 Göttingen, Germany
| | - Neil Singh
- Department of General Microbiology, Institute of Microbiology and Genetics, GZMB, Georg-August-University Göttingen, 37077 Göttingen, Germany
| | - Wim J H Hagen
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany
| | - Patrick Cramer
- Department of Molecular Biology, Max-Planck-Institute for Biophysical Chemistry, 37077 Göttingen, Germany
| | - Jörg Stülke
- Department of General Microbiology, Institute of Microbiology and Genetics, GZMB, Georg-August-University Göttingen, 37077 Göttingen, Germany
| | - Julia Mahamid
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany.
| | - Juri Rappsilber
- Bioanalytics Unit, Institute of Biotechnology, Technische Universität Berlin, 13355 Berlin, Germany. .,Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh, EH9 3BF, UK
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34
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Golubev A, Fatkhullin B, Khusainov I, Jenner L, Gabdulkhakov A, Validov S, Yusupova G, Yusupov M, Usachev K. Cryo‐EM structure of the ribosome functional complex of the human pathogen
Staphylococcus aureus
at 3.2 Å resolution. FEBS Lett 2020; 594:3551-3567. [DOI: 10.1002/1873-3468.13915] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 08/11/2020] [Accepted: 08/17/2020] [Indexed: 12/14/2022]
Affiliation(s)
- Alexander Golubev
- Laboratory of Structural Biology Institute of Fundamental Medicine and Biology Kazan Federal University Russia
- Département de Biologie et de Génomique Structurales Institut de Génétique et de Biologie Moléculaire et Cellulaire CNRS UMR7104INSERM U964Université de Strasbourg Illkirch France
| | - Bulat Fatkhullin
- Laboratory of Structural Biology Institute of Fundamental Medicine and Biology Kazan Federal University Russia
- Institute of Protein Research Russian Academy of Sciences Puschino Russia
| | - Iskander Khusainov
- Laboratory of Structural Biology Institute of Fundamental Medicine and Biology Kazan Federal University Russia
- Department of Molecular Sociology Max Planck Institute of Biophysics Frankfurt am Main Germany
| | - Lasse Jenner
- Département de Biologie et de Génomique Structurales Institut de Génétique et de Biologie Moléculaire et Cellulaire CNRS UMR7104INSERM U964Université de Strasbourg Illkirch France
| | - Azat Gabdulkhakov
- Laboratory of Structural Biology Institute of Fundamental Medicine and Biology Kazan Federal University Russia
- Institute of Protein Research Russian Academy of Sciences Puschino Russia
| | - Shamil Validov
- Laboratory of Structural Biology Institute of Fundamental Medicine and Biology Kazan Federal University Russia
| | - Gulnara Yusupova
- Département de Biologie et de Génomique Structurales Institut de Génétique et de Biologie Moléculaire et Cellulaire CNRS UMR7104INSERM U964Université de Strasbourg Illkirch France
| | - Marat Yusupov
- Laboratory of Structural Biology Institute of Fundamental Medicine and Biology Kazan Federal University Russia
- Département de Biologie et de Génomique Structurales Institut de Génétique et de Biologie Moléculaire et Cellulaire CNRS UMR7104INSERM U964Université de Strasbourg Illkirch France
| | - Konstantin Usachev
- Laboratory of Structural Biology Institute of Fundamental Medicine and Biology Kazan Federal University Russia
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35
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Dever TE, Ivanov IP, Sachs MS. Conserved Upstream Open Reading Frame Nascent Peptides That Control Translation. Annu Rev Genet 2020; 54:237-264. [PMID: 32870728 DOI: 10.1146/annurev-genet-112618-043822] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Cells utilize transcriptional and posttranscriptional mechanisms to alter gene expression in response to environmental cues. Gene-specific controls, including changing the translation of specific messenger RNAs (mRNAs), provide a rapid means to respond precisely to different conditions. Upstream open reading frames (uORFs) are known to control the translation of mRNAs. Recent studies in bacteria and eukaryotes have revealed the functions of evolutionarily conserved uORF-encoded peptides. Some of these uORF-encoded nascent peptides enable responses to specific metabolites to modulate the translation of their mRNAs by stalling ribosomes and through ribosome stalling may also modulate the level of their mRNAs. In this review, we highlight several examples of conserved uORF nascent peptides that stall ribosomes to regulate gene expression in response to specific metabolites in bacteria, fungi, mammals, and plants.
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Affiliation(s)
- Thomas E Dever
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA; ,
| | - Ivaylo P Ivanov
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA; ,
| | - Matthew S Sachs
- Department of Biology, Texas A&M University, College Station, Texas 77843, USA;
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36
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Nicholson D, Edwards TA, O'Neill AJ, Ranson NA. Structure of the 70S Ribosome from the Human Pathogen Acinetobacter baumannii in Complex with Clinically Relevant Antibiotics. Structure 2020; 28:1087-1100.e3. [PMID: 32857965 PMCID: PMC7546915 DOI: 10.1016/j.str.2020.08.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 07/06/2020] [Accepted: 08/07/2020] [Indexed: 12/19/2022]
Abstract
Acinetobacter baumannii is a Gram-negative bacterium primarily associated with hospital-acquired, often multidrug-resistant (MDR) infections. The ribosome-targeting antibiotics amikacin and tigecycline are among the limited arsenal of drugs available for treatment of such infections. We present high-resolution structures of the 70S ribosome from A. baumannii in complex with these antibiotics, as determined by cryoelectron microscopy. Comparison with the ribosomes of other bacteria reveals several unique structural features at functionally important sites, including around the exit of the polypeptide tunnel and the periphery of the subunit interface. The structures also reveal the mode and site of interaction of these drugs with the ribosome. This work paves the way for the design of new inhibitors of translation to address infections caused by MDR A. baumannii. Cryo-EM structures of the ribosome from the pathogenic bacteria A. baumannii Unique structural features compared with other bacterial ribosomes The site and mode of binding of amikacin and tigecycline to this ribosome A putative alternative tigecycline-binding site at the 50S central protuberance
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Affiliation(s)
- David Nicholson
- Astbury Centre for Structural Molecular Biology, School of Molecular & Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Thomas A Edwards
- Astbury Centre for Structural Molecular Biology, School of Molecular & Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK.
| | - Alex J O'Neill
- Astbury Centre for Structural Molecular Biology, School of Molecular & Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK.
| | - Neil A Ranson
- Astbury Centre for Structural Molecular Biology, School of Molecular & Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK.
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37
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Mechanism of ribosome shutdown by RsfS in Staphylococcus aureus revealed by integrative structural biology approach. Nat Commun 2020; 11:1656. [PMID: 32245971 PMCID: PMC7125091 DOI: 10.1038/s41467-020-15517-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Accepted: 03/05/2020] [Indexed: 11/08/2022] Open
Abstract
For the sake of energy preservation, bacteria, upon transition to stationary phase, tone down their protein synthesis. This process is favored by the reversible binding of small stress-induced proteins to the ribosome to prevent unnecessary translation. One example is the conserved bacterial ribosome silencing factor (RsfS) that binds to uL14 protein onto the large ribosomal subunit and prevents its association with the small subunit. Here we describe the binding mode of Staphylococcus aureus RsfS to the large ribosomal subunit and present a 3.2 Å resolution cryo-EM reconstruction of the 50S-RsfS complex together with the crystal structure of uL14-RsfS complex solved at 2.3 Å resolution. The understanding of the detailed landscape of RsfS-uL14 interactions within the ribosome shed light on the mechanism of ribosome shutdown in the human pathogen S. aureus and might deliver a novel target for pharmacological drug development and treatment of bacterial infections.
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38
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Babaylova ES, Gopanenko AV, Bulygin KN, Tupikin AE, Kabilov MR, Malygin AA, Karpova GG. mRNA regions where 80S ribosomes pause during translation elongation in vivo interact with protein uS19, a component of the decoding site. Nucleic Acids Res 2020; 48:912-923. [PMID: 31802126 PMCID: PMC6954443 DOI: 10.1093/nar/gkz1145] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 11/21/2019] [Accepted: 11/25/2019] [Indexed: 11/25/2022] Open
Abstract
In eukaryotic ribosomes, the conserved protein uS19, formerly known as S15, extends with its C-terminal tail to the decoding site. The cross-linking of uS19 to the A site codon has been detected using synthetic mRNAs bearing 4-thiouridine (s4U) residues. Here, we showed that the A-site tRNA prevents this cross-linking and that the P site codon does not contact uS19. Next, we focused on determining uS19-mRNA interactions in vivo by applying the photoactivatable-ribonucleoside enhancing cross-linking and immunoprecipitation method to a stable HEK293 cell line producing FLAG-tagged uS19 and grown in a medium containing s4U. We found that when translation was stopped by cycloheximide, uS19 was efficiently cross-linked to mRNA regions with a high frequency of Glu, Lys and, more rarely, Arg codons. The results indicate that the complexes, in which the A site codon is not involved in the formation of the mRNA-tRNA duplex, are present among the cycloheximide-arrested 80S complexes, which implies pausing of elongating ribosomes at the above mRNA regions. Thus, our findings demonstrate that the human ribosomal protein uS19 interacts with mRNAs during translation elongation and highlight the regions of mRNAs where ribosome pausing occurs, bringing new structural and functional insights into eukaryotic translation in vivo.
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Affiliation(s)
- Elena S Babaylova
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Prospekt Lavrentieva 8, Novosibirsk 630090, Russia
| | - Alexander V Gopanenko
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Prospekt Lavrentieva 8, Novosibirsk 630090, Russia
| | - Konstantin N Bulygin
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Prospekt Lavrentieva 8, Novosibirsk 630090, Russia
| | - Alexey E Tupikin
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Prospekt Lavrentieva 8, Novosibirsk 630090, Russia
| | - Marsel R Kabilov
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Prospekt Lavrentieva 8, Novosibirsk 630090, Russia
| | - Alexey A Malygin
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Prospekt Lavrentieva 8, Novosibirsk 630090, Russia.,Novosibirsk State University, Pirogova Str. 2, Novosibirsk 630090, Russia
| | - Galina G Karpova
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Prospekt Lavrentieva 8, Novosibirsk 630090, Russia.,Novosibirsk State University, Pirogova Str. 2, Novosibirsk 630090, Russia
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39
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Takamatsu S, Ohashi Y, Onoue N, Tajima Y, Imamichi T, Yonezawa S, Morimoto K, Onouchi H, Yamashita Y, Naito S. Reverse genetics-based biochemical studies of the ribosomal exit tunnel constriction region in eukaryotic ribosome stalling: spatial allocation of the regulatory nascent peptide at the constriction. Nucleic Acids Res 2020; 48:1985-1999. [PMID: 31875230 PMCID: PMC7038982 DOI: 10.1093/nar/gkz1190] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 12/09/2019] [Accepted: 12/12/2019] [Indexed: 11/12/2022] Open
Abstract
A number of regulatory nascent peptides have been shown to regulate gene expression by causing programmed ribosome stalling during translation. Nascent peptide emerges from the ribosome through the exit tunnel, and one-third of the way along which β-loop structures of ribosomal proteins uL4 and uL22 protrude into the tunnel to form the constriction region. Structural studies have shown interactions between nascent peptides and the exit tunnel components including the constriction region. In eukaryotes, however, there is a lack of genetic studies for the involvement of the constriction region in ribosome stalling. Here, we established transgenic Arabidopsis lines that carry mutations in the β-loop structure of uL4. Translation analyses using a cell-free translation system derived from the transgenic Arabidopsis carrying the mutant ribosome showed that the uL4 mutations reduced the ribosome stalling of four eukaryotic stalling systems, including those for which stalled structures have been solved. Our data, which showed differential effects of the uL4 mutations depending on the stalling systems, explained the spatial allocations of the nascent peptides at the constriction that were deduced by structural studies. Conversely, our data may predict allocation of the nascent peptide at the constriction of stalling systems for which structural studies are not done.
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Affiliation(s)
- Seidai Takamatsu
- Division of Life Science, Graduate School of Life Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Yubun Ohashi
- Frontiers in Biosciences, Graduate School of Agriculture, Hokkaido University, Sapporo 060-8589, Japan
| | - Noriyuki Onoue
- Division of Life Science, Graduate School of Life Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Yoko Tajima
- Department of Applied Bioscience, Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan
| | - Tomoya Imamichi
- Division of Life Science, Graduate School of Life Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Shinya Yonezawa
- Division of Life Science, Graduate School of Life Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Kyoko Morimoto
- Department of Applied Bioscience, Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan
| | - Hitoshi Onouchi
- Frontiers in Biosciences, Graduate School of Agriculture, Hokkaido University, Sapporo 060-8589, Japan.,Department of Applied Bioscience, Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan.,Research Group of Applied Bioscience, Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan
| | - Yui Yamashita
- Frontiers in Biosciences, Graduate School of Agriculture, Hokkaido University, Sapporo 060-8589, Japan.,Department of Applied Bioscience, Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan.,Research Group of Applied Bioscience, Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan
| | - Satoshi Naito
- Division of Life Science, Graduate School of Life Science, Hokkaido University, Sapporo 060-0810, Japan.,Department of Applied Bioscience, Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan.,Research Group of Applied Bioscience, Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan
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40
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Cotranslational Folding of Proteins on the Ribosome. Biomolecules 2020; 10:biom10010097. [PMID: 31936054 PMCID: PMC7023365 DOI: 10.3390/biom10010097] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 12/20/2019] [Accepted: 12/25/2019] [Indexed: 02/04/2023] Open
Abstract
Many proteins in the cell fold cotranslationally within the restricted space of the polypeptide exit tunnel or at the surface of the ribosome. A growing body of evidence suggests that the ribosome can alter the folding trajectory in many different ways. In this review, we summarize the recent examples of how translation affects folding of single-domain, multiple-domain and oligomeric proteins. The vectorial nature of translation, the spatial constraints of the exit tunnel, and the electrostatic properties of the ribosome-nascent peptide complex define the onset of early folding events. The ribosome can facilitate protein compaction, induce the formation of intermediates that are not observed in solution, or delay the onset of folding. Examples of single-domain proteins suggest that early compaction events can define the folding pathway for some types of domain structures. Folding of multi-domain proteins proceeds in a domain-wise fashion, with each domain having its role in stabilizing or destabilizing neighboring domains. Finally, the assembly of protein complexes can also begin cotranslationally. In all these cases, the ribosome helps the nascent protein to attain a native fold and avoid the kinetic traps of misfolding.
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41
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Release factor-dependent ribosome rescue by BrfA in the Gram-positive bacterium Bacillus subtilis. Nat Commun 2019; 10:5397. [PMID: 31776341 PMCID: PMC6881298 DOI: 10.1038/s41467-019-13408-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Accepted: 11/07/2019] [Indexed: 12/14/2022] Open
Abstract
Rescue of the ribosomes from dead-end translation complexes, such as those on truncated (non-stop) mRNA, is essential for the cell. Whereas bacteria use trans-translation for ribosome rescue, some Gram-negative species possess alternative and release factor (RF)-dependent rescue factors, which enable an RF to catalyze stop-codon-independent polypeptide release. We now discover that the Gram-positive Bacillus subtilis has an evolutionarily distinct ribosome rescue factor named BrfA. Genetic analysis shows that B. subtilis requires the function of either trans-translation or BrfA for growth, even in the absence of proteotoxic stresses. Biochemical and cryo-electron microscopy (cryo-EM) characterization demonstrates that BrfA binds to non-stop stalled ribosomes, recruits homologous RF2, but not RF1, and induces its transition into an open active conformation. Although BrfA is distinct from E. coli ArfA, they use convergent strategies in terms of mode of action and expression regulation, indicating that many bacteria may have evolved as yet unidentified ribosome rescue systems. In bacteria, the conserved trans-translation system serves as the primary pathway of ribosome rescue, but many species can also use alternative rescue pathways. Here the authors report that in B. subtilis, the rescue factor BrfA binds to non-stop stalled ribosomes, recruits RF2 but not RF1, and induces transition of the ribosome into an open active conformation.
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42
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Ito K, Mori H, Chiba S. Monitoring substrate enables real-time regulation of a protein localization pathway. FEMS Microbiol Lett 2019; 365:4983124. [PMID: 29790986 DOI: 10.1093/femsle/fny109] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Accepted: 04/23/2018] [Indexed: 12/20/2022] Open
Abstract
Protein localization machinery supports cell survival and physiology, suggesting the potential importance of its expression regulation. Here, we summarize a remarkable scheme of regulation, which allows real-time feedback regulation of the machinery expression. A class of regulatory nascent polypeptides, called monitoring substrates, undergoes force-sensitive translation arrest. The resulting ribosome stalling on the mRNA then affects mRNA folding to expose the ribosome-binding site of the downstream target gene and upregulate its translation. The target gene encodes a component of the localization machinery, whose physical action against the monitoring substrate leads to arrest cancellation. Thus, this scheme of feedback loop allows the cell to adjust the amount of the machinery to correlate inversely with the effectiveness of the process at a given moment. The system appears to have emerged late in evolution, in which a narrow range of organisms selected a distinct monitoring substrate-machinery combination. Currently, regulatory systems of SecM-SecA, VemP-SecDF2 and MifM-YidC2 are known to occur in different bacterial species.
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Affiliation(s)
- Koreaki Ito
- Faculty of Life Sciences and Institute for Protein Dynamics, Kyoto Sangyo University, Kita-Ku, Kyoto 603-8555, Japan
| | - Hiroyuki Mori
- Japan and Institute for Frontier Life and Medical Sciences, Kyoto University, Sakyo-Ku, Kyoto, 606-8507, Japan
| | - Shinobu Chiba
- Faculty of Life Sciences and Institute for Protein Dynamics, Kyoto Sangyo University, Kita-Ku, Kyoto 603-8555, Japan
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43
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Halfon Y, Matzov D, Eyal Z, Bashan A, Zimmerman E, Kjeldgaard J, Ingmer H, Yonath A. Exit tunnel modulation as resistance mechanism of S. aureus erythromycin resistant mutant. Sci Rep 2019; 9:11460. [PMID: 31391518 PMCID: PMC6685948 DOI: 10.1038/s41598-019-48019-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 07/25/2019] [Indexed: 12/16/2022] Open
Abstract
The clinical use of the antibiotic erythromycin (ery) is hampered owing to the spread of resistance genes that are mostly mutating rRNA around the ery binding site at the entrance to the protein exit tunnel. Additional effective resistance mechanisms include deletion or insertion mutations in ribosomal protein uL22, which lead to alterations of the exit tunnel shape, located 16 Å away from the drug's binding site. We determined the cryo-EM structures of the Staphylococcus aureus 70S ribosome, and its ery bound complex with a two amino acid deletion mutation in its ß hairpin loop, which grants the bacteria resistance to ery. The structures reveal that, although the binding of ery is stable, the movement of the flexible shorter uL22 loop towards the tunnel wall creates a wider path for nascent proteins, thus enabling bypass of the barrier formed by the drug. Moreover, upon drug binding, the tunnel widens further.
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Affiliation(s)
- Yehuda Halfon
- The Weizmann Institute of Science, The Department of structural biology, Rehovot, 7610001, Israel
| | - Donna Matzov
- The Weizmann Institute of Science, The Department of structural biology, Rehovot, 7610001, Israel
| | - Zohar Eyal
- The Weizmann Institute of Science, The Department of structural biology, Rehovot, 7610001, Israel
| | - Anat Bashan
- The Weizmann Institute of Science, The Department of structural biology, Rehovot, 7610001, Israel
| | - Ella Zimmerman
- The Weizmann Institute of Science, The Department of structural biology, Rehovot, 7610001, Israel
| | - Jette Kjeldgaard
- National Food Institute, Technical University of Denmark, Kemitorvet, DK-2800, Kgs, Lyngby, Denmark
| | - Hanne Ingmer
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, 1870, Frederiksberg, Denmark
| | - Ada Yonath
- The Weizmann Institute of Science, The Department of structural biology, Rehovot, 7610001, Israel.
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44
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Shanmuganathan V, Schiller N, Magoulopoulou A, Cheng J, Braunger K, Cymer F, Berninghausen O, Beatrix B, Kohno K, von Heijne G, Beckmann R. Structural and mutational analysis of the ribosome-arresting human XBP1u. eLife 2019; 8:46267. [PMID: 31246176 PMCID: PMC6624018 DOI: 10.7554/elife.46267] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 06/20/2019] [Indexed: 12/17/2022] Open
Abstract
XBP1u, a central component of the unfolded protein response (UPR), is a mammalian protein containing a functionally critical translational arrest peptide (AP). Here, we present a 3 Å cryo-EM structure of the stalled human XBP1u AP. It forms a unique turn in the ribosomal exit tunnel proximal to the peptidyl transferase center where it causes a subtle distortion, thereby explaining the temporary translational arrest induced by XBP1u. During ribosomal pausing the hydrophobic region 2 (HR2) of XBP1u is recognized by SRP, but fails to efficiently gate the Sec61 translocon. An exhaustive mutagenesis scan of the XBP1u AP revealed that only 8 out of 20 mutagenized positions are optimal; in the remaining 12 positions, we identify 55 different mutations increase the level of translational arrest. Thus, the wildtype XBP1u AP induces only an intermediate level of translational arrest, allowing efficient targeting by SRP without activating the Sec61 channel.
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Affiliation(s)
- Vivekanandan Shanmuganathan
- Gene Center, Department of Biochemistry, Center for integrated Protein Science Munich (CiPSM), Ludwig-Maximilians-Universität München, Munich, Germany
| | - Nina Schiller
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | | | - Jingdong Cheng
- Gene Center, Department of Biochemistry, Center for integrated Protein Science Munich (CiPSM), Ludwig-Maximilians-Universität München, Munich, Germany
| | - Katharina Braunger
- Gene Center, Department of Biochemistry, Center for integrated Protein Science Munich (CiPSM), Ludwig-Maximilians-Universität München, Munich, Germany
| | - Florian Cymer
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Otto Berninghausen
- Gene Center, Department of Biochemistry, Center for integrated Protein Science Munich (CiPSM), Ludwig-Maximilians-Universität München, Munich, Germany
| | - Birgitta Beatrix
- Gene Center, Department of Biochemistry, Center for integrated Protein Science Munich (CiPSM), Ludwig-Maximilians-Universität München, Munich, Germany
| | - Kenji Kohno
- Institute for Research Initiatives, Nara Institute of Science and Technology, Takayama, Japan
| | - Gunnar von Heijne
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden.,Science for Life Laboratory, Stockholm University, Solna, Sweden
| | - Roland Beckmann
- Gene Center, Department of Biochemistry, Center for integrated Protein Science Munich (CiPSM), Ludwig-Maximilians-Universität München, Munich, Germany
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45
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Hockenberry AJ, Jewett MC, Amaral LAN, Wilke CO. Within-Gene Shine-Dalgarno Sequences Are Not Selected for Function. Mol Biol Evol 2019; 35:2487-2498. [PMID: 30085185 DOI: 10.1093/molbev/msy150] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The Shine-Dalgarno (SD) sequence motif facilitates translation initiation and is frequently found upstream of bacterial start codons. However, thousands of instances of this motif occur throughout the middle of protein coding genes in a typical bacterial genome. Here, we use comparative evolutionary analysis to test whether SD sequences located within genes are functionally constrained. We measure the conservation of SD sequences across Enterobacteriales, and find that they are significantly less conserved than expected. Further, the strongest SD sequences are the least conserved whereas we find evidence of conservation for the weakest possible SD sequences given amino acid constraints. Our findings indicate that most SD sequences within genes are likely to be deleterious and removed via selection. To illustrate the origin of these deleterious costs, we show that ATG start codons are significantly depleted downstream of SD sequences within genes, highlighting the constraint that these sequences impose on the surrounding nucleotides to minimize the potential for erroneous translation initiation.
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Affiliation(s)
- Adam J Hockenberry
- Department of Integrative Biology, The University of Texas at Austin, Austin, TX
| | - Michael C Jewett
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL.,Chemistry of Life Processes Institute, Northwestern University, Evanston, IL.,Center for Synthetic Biology, Northwestern University, Evanston, IL.,Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Chicago, IL.,Simpson Querrey Institute, Northwestern University, Evanston, IL
| | - Luís A N Amaral
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL.,Northwestern Institute on Complex Systems, Northwestern University, Evanston, IL
| | - Claus O Wilke
- Department of Integrative Biology, The University of Texas at Austin, Austin, TX
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46
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Abstract
Ribosomes are biological nanomachine that synthesise all proteins within a cell. It took decades to reveal the architecture of this essential cellular component. To understand the structure -function relationship of this nanomachine needed the utilisisation of different biochemical, biophysical and structural techniques. Structural studies combined with mutagenesis of the different ribosomal complexes comprising various RNAs and proteins enabled us to understand how this machine works inside a cell. Nowadays quite a number of ribosomal structures were published that confirmed biochemical studies on particular steps of protein synthesis by the ribosome . Four major steps were identified: initiation , elongation, termination and recycling. These steps lead us to the important question how the ribosome function can be regulated. Advances in technology for cryo electron microscopy: sample preparations, image recording, developments in algorithms for image analysis and processing significantly helped in revelation of structural details of the ribosome . We now have a library of ribosome structures from prokaryotes to eukaryotes that enable us to understand the complex mechanics of this nanomachine. As this structural library continues to grow, we gradually improve our understanding of this process and how it can be regulated and how the specific ribosomes can be stalled or activated, or completely disabled. This article provides a comprehensive overview of ribosomal structures that represent structural snapshots of the ribosome at its different functional states. Better understanding rises more particular questions that have to be addressed by determination structures of more complexes.Synopsis: Structural biology of the ribosome.
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Affiliation(s)
- Abid Javed
- Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck College, Malet Street, London, WC1E 7HX, UK
| | - Elena V Orlova
- Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck College, Malet Street, London, WC1E 7HX, UK.
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47
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Vázquez-Laslop N, Mankin AS. How Macrolide Antibiotics Work. Trends Biochem Sci 2018; 43:668-684. [PMID: 30054232 PMCID: PMC6108949 DOI: 10.1016/j.tibs.2018.06.011] [Citation(s) in RCA: 169] [Impact Index Per Article: 28.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 06/17/2018] [Accepted: 06/29/2018] [Indexed: 01/24/2023]
Abstract
Macrolide antibiotics inhibit protein synthesis by targeting the bacterial ribosome. They bind at the nascent peptide exit tunnel and partially occlude it. Thus, macrolides have been viewed as 'tunnel plugs' that stop the synthesis of every protein. More recent evidence, however, demonstrates that macrolides selectively inhibit the translation of a subset of cellular proteins, and that their action crucially depends on the nascent protein sequence and on the antibiotic structure. Therefore, macrolides emerge as modulators of translation rather than as global inhibitors of protein synthesis. The context-specific action of macrolides is the basis for regulating the expression of resistance genes. Understanding the details of the mechanism of macrolide action may inform rational design of new drugs and unveil important principles of translation regulation.
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Affiliation(s)
- Nora Vázquez-Laslop
- Center for Biomolecular Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA.
| | - Alexander S Mankin
- Center for Biomolecular Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA.
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48
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Structural basis for antibiotic resistance mediated by the Bacillus subtilis ABCF ATPase VmlR. Proc Natl Acad Sci U S A 2018; 115:8978-8983. [PMID: 30126986 PMCID: PMC6130385 DOI: 10.1073/pnas.1808535115] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The recent increase in multidrug-resistant pathogenic bacteria is limiting the utility of our current arsenal of clinically important antibiotics. The development of improved antibiotics would therefore benefit from a better understanding of the current resistance mechanisms employed by bacteria. Many Gram-positive bacteria, including pathogenic Staphylococcus aureus and Enterococcus faecalis, utilize ribosome protection proteins to confer resistance to medically relevant antibiotics, such as streptogramins A, lincosamides, and pleuromutilins. We have employed cryo-electron microscopy to reveal the structural basis for how the Bacillus subtilis VmlR protein binds to the ribosome to confer resistance to the streptogramin A antibiotic virginiamycin M, the lincosamide lincomycin, and the pleuromutilin tiamulin. Many Gram-positive pathogenic bacteria employ ribosomal protection proteins (RPPs) to confer resistance to clinically important antibiotics. In Bacillus subtilis, the RPP VmlR confers resistance to lincomycin (Lnc) and the streptogramin A (SA) antibiotic virginiamycin M (VgM). VmlR is an ATP-binding cassette (ABC) protein of the F type, which, like other antibiotic resistance (ARE) ABCF proteins, is thought to bind to antibiotic-stalled ribosomes and promote dissociation of the drug from its binding site. To investigate the molecular mechanism by which VmlR confers antibiotic resistance, we have determined a cryo-electron microscopy (cryo-EM) structure of an ATPase-deficient B. subtilis VmlR-EQ2 mutant in complex with a B. subtilis ErmDL-stalled ribosomal complex (SRC). The structure reveals that VmlR binds within the E site of the ribosome, with the antibiotic resistance domain (ARD) reaching into the peptidyltransferase center (PTC) of the ribosome and a C-terminal extension (CTE) making contact with the small subunit (SSU). To access the PTC, VmlR induces a conformational change in the P-site tRNA, shifting the acceptor arm out of the PTC and relocating the CCA end of the P-site tRNA toward the A site. Together with microbiological analyses, our study indicates that VmlR allosterically dissociates the drug from its ribosomal binding site and exhibits specificity to dislodge VgM, Lnc, and the pleuromutilin tiamulin (Tia), but not chloramphenicol (Cam), linezolid (Lnz), nor the macrolide erythromycin (Ery).
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49
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Fujiwara K, Ito K, Chiba S. MifM-instructed translation arrest involves nascent chain interactions with the exterior as well as the interior of the ribosome. Sci Rep 2018; 8:10311. [PMID: 29985442 PMCID: PMC6037786 DOI: 10.1038/s41598-018-28628-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Accepted: 06/25/2018] [Indexed: 11/09/2022] Open
Abstract
Bacillus subtilis MifM is a monitoring substrate of the YidC pathways of protein integration into the membrane and controls the expression of the YidC2 (YqjG) homolog by undergoing regulated translational elongation arrest. The elongation arrest requires interactions between the MifM nascent polypeptide and the ribosomal components near the peptidyl transferase center (PTC) as well as at the constriction site of the ribosomal exit tunnel. Here, we addressed the roles played by more N-terminal regions of MifM and found that, in addition to the previously-identified arrest-provoking elements, the MifM residues 41-60 likely located at the tunnel exit and outside the ribosome contribute to the full induction of elongation arrest. Mutational effects of the cytosolically exposed part of the ribosomal protein uL23 suggested its involvement in the elongation arrest, presumably by interacting with the extra-ribosomal portion of MifM. In vitro translation with reconstituted translation components recapitulated the effects of the mutations at the 41-60 segment, reinforcing the importance of direct molecular interactions between the nascent chain and the ribosome. These results indicate that the nascent MifM polypeptide interacts extensively with the ribosome both from within and without to direct the elongation halt and consequent up-regulation of YidC2.
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Affiliation(s)
- Keigo Fujiwara
- Faculty of Life Sciences and Institute for Protein Dynamics, Kyoto Sangyo University, Motoyama, Kamigamo, Kita-Ku, Kyoto, 603-8555, Japan
| | - Koreaki Ito
- Faculty of Life Sciences and Institute for Protein Dynamics, Kyoto Sangyo University, Motoyama, Kamigamo, Kita-Ku, Kyoto, 603-8555, Japan
| | - Shinobu Chiba
- Faculty of Life Sciences and Institute for Protein Dynamics, Kyoto Sangyo University, Motoyama, Kamigamo, Kita-Ku, Kyoto, 603-8555, Japan.
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50
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Melnikov S, Manakongtreecheep K, Söll D. Revising the Structural Diversity of Ribosomal Proteins Across the Three Domains of Life. Mol Biol Evol 2018; 35:1588-1598. [PMID: 29529322 PMCID: PMC5995209 DOI: 10.1093/molbev/msy021] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Ribosomal proteins are indispensable components of a living cell, and yet their structures are remarkably diverse in different species. Here we use manually curated structural alignments to provide a comprehensive catalog of structural variations in homologous ribosomal proteins from bacteria, archaea, eukaryotes, and eukaryotic organelles. By resolving numerous ambiguities and errors of automated structural and sequence alignments, we uncover a whole new class of structural variations that reside within seemingly conserved segments of ribosomal proteins. We then illustrate that these variations reflect an apparent adaptation of ribosomal proteins to the specific environments and lifestyles of living species. Finally, we show that most of these structural variations reside within nonglobular extensions of ribosomal proteins-protein segments that are thought to promote ribosome biogenesis by stabilizing the proper folding of ribosomal RNA. We show that although the extensions are thought to be the most ancient peptides on our planet, they are in fact the most rapidly evolving and most structurally and functionally diverse segments of ribosomal proteins. Overall, our work illustrates that, despite being long considered as slowly evolving and highly conserved, ribosomal proteins are more complex and more specialized than is generally recognized.
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Affiliation(s)
- Sergey Melnikov
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT
| | | | - Dieter Söll
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT
- Department of Chemistry, Yale University, New Haven, CT
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