51
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Watson ZL, Ward FR, Méheust R, Ad O, Schepartz A, Banfield JF, Cate JHD. Structure of the bacterial ribosome at 2 Å resolution. eLife 2020; 9:e60482. [PMID: 32924932 PMCID: PMC7550191 DOI: 10.7554/elife.60482] [Citation(s) in RCA: 129] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Accepted: 09/11/2020] [Indexed: 12/31/2022] Open
Abstract
Using cryo-electron microscopy (cryo-EM), we determined the structure of the Escherichia coli 70S ribosome with a global resolution of 2.0 Å. The maps reveal unambiguous positioning of protein and RNA residues, their detailed chemical interactions, and chemical modifications. Notable features include the first examples of isopeptide and thioamide backbone substitutions in ribosomal proteins, the former likely conserved in all domains of life. The maps also reveal extensive solvation of the small (30S) ribosomal subunit, and interactions with A-site and P-site tRNAs, mRNA, and the antibiotic paromomycin. The maps and models of the bacterial ribosome presented here now allow a deeper phylogenetic analysis of ribosomal components including structural conservation to the level of solvation. The high quality of the maps should enable future structural analyses of the chemical basis for translation and aid the development of robust tools for cryo-EM structure modeling and refinement.
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Affiliation(s)
- Zoe L Watson
- Department of Chemistry, University of California, BerkeleyBerkeleyUnited States
| | - Fred R Ward
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Raphaël Méheust
- Innovative Genomics Institute, University of California, BerkeleyBerkeleyUnited States
- Earth and Planetary Science, University of California, BerkeleyBerkeleyUnited States
| | - Omer Ad
- Department of Chemistry, Yale UniversityNew HavenUnited States
| | - Alanna Schepartz
- Department of Chemistry, University of California, BerkeleyBerkeleyUnited States
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Jillian F Banfield
- Innovative Genomics Institute, University of California, BerkeleyBerkeleyUnited States
- Earth and Planetary Science, University of California, BerkeleyBerkeleyUnited States
- Environmental Science, Policy and Management, University of California BerkeleyBerkeleyUnited States
| | - Jamie HD Cate
- Department of Chemistry, University of California, BerkeleyBerkeleyUnited States
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National LaboratoryBerkeleyUnited States
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52
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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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53
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Disruption of evolutionarily correlated tRNA elements impairs accurate decoding. Proc Natl Acad Sci U S A 2020; 117:16333-16338. [PMID: 32601241 DOI: 10.1073/pnas.2004170117] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Bacterial transfer RNAs (tRNAs) contain evolutionarily conserved sequences and modifications that ensure uniform binding to the ribosome and optimal translational accuracy despite differences in their aminoacyl attachments and anticodon nucleotide sequences. In the tRNA anticodon stem-loop, the anticodon sequence is correlated with a base pair in the anticodon loop (nucleotides 32 and 38) to tune the binding of each tRNA to the decoding center in the ribosome. Disruption of this correlation renders the ribosome unable to distinguish correct from incorrect tRNAs. The molecular basis for how these two tRNA features combine to ensure accurate decoding is unclear. Here, we solved structures of the bacterial ribosome containing either wild-type [Formula: see text] or [Formula: see text] containing a reversed 32-38 pair on cognate and near-cognate codons. Structures of wild-type [Formula: see text] bound to the ribosome reveal 23S ribosomal RNA (rRNA) nucleotide A1913 positional changes that are dependent on whether the codon-anticodon interaction is cognate or near cognate. Further, the 32-38 pair is destabilized in the context of a near-cognate codon-anticodon pair. Reversal of the pairing in [Formula: see text] ablates A1913 movement regardless of whether the interaction is cognate or near cognate. These results demonstrate that disrupting 32-38 and anticodon sequences alters interactions with the ribosome that directly contribute to misreading.
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54
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Rodnina MV, Korniy N, Klimova M, Karki P, Peng BZ, Senyushkina T, Belardinelli R, Maracci C, Wohlgemuth I, Samatova E, Peske F. Translational recoding: canonical translation mechanisms reinterpreted. Nucleic Acids Res 2020; 48:1056-1067. [PMID: 31511883 PMCID: PMC7026636 DOI: 10.1093/nar/gkz783] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 08/21/2019] [Accepted: 08/30/2019] [Indexed: 01/15/2023] Open
Abstract
During canonical translation, the ribosome moves along an mRNA from the start to the stop codon in exact steps of one codon at a time. The collinearity of the mRNA and the protein sequence is essential for the quality of the cellular proteome. Spontaneous errors in decoding or translocation are rare and result in a deficient protein. However, dedicated recoding signals in the mRNA can reprogram the ribosome to read the message in alternative ways. This review summarizes the recent advances in understanding the mechanisms of three types of recoding events: stop-codon readthrough, –1 ribosome frameshifting and translational bypassing. Recoding events provide insights into alternative modes of ribosome dynamics that are potentially applicable to other non-canonical modes of prokaryotic and eukaryotic translation.
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Affiliation(s)
- Marina V Rodnina
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Göttingen 37077, Germany
| | - Natalia Korniy
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Göttingen 37077, Germany
| | - Mariia Klimova
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Göttingen 37077, Germany
| | - Prajwal Karki
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Göttingen 37077, Germany
| | - Bee-Zen Peng
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Göttingen 37077, Germany
| | - Tamara Senyushkina
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Göttingen 37077, Germany
| | - Riccardo Belardinelli
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Göttingen 37077, Germany
| | - Cristina Maracci
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Göttingen 37077, Germany
| | - Ingo Wohlgemuth
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Göttingen 37077, Germany
| | - Ekaterina Samatova
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Göttingen 37077, Germany
| | - Frank Peske
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Göttingen 37077, Germany
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55
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Elongation factor-Tu can repetitively engage aminoacyl-tRNA within the ribosome during the proofreading stage of tRNA selection. Proc Natl Acad Sci U S A 2020; 117:3610-3620. [PMID: 32024753 PMCID: PMC7035488 DOI: 10.1073/pnas.1904469117] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Elongation factor Tu (EF-Tu) facilitates rapid and accurate selection of aminoacyl-tRNA (aa-tRNA) by the bacterial ribosome during protein synthesis. We show that EF-Tu dissociates from the ribosome as aa-tRNA navigates the accommodation corridor en route to peptide bond formation. We find that EF-Tu’s release from the ribosome during aa-tRNA selection can be reversible. We also demonstrate that new ternary complex formation, accompanied by futile cycles of GTP hydrolysis, can occur on aa-tRNA bound within the ribosome. These findings inform on the decoding mechanism, the contributions of EF-Tu to the fidelity of translation, and the potential consequences of reduced rates of peptide bond formation on cellular physiology. The substrate for ribosomes actively engaged in protein synthesis is a ternary complex of elongation factor Tu (EF-Tu), aminoacyl-tRNA (aa-tRNA), and GTP. EF-Tu plays a critical role in mRNA decoding by increasing the rate and fidelity of aa-tRNA selection at each mRNA codon. Here, using three-color single-molecule fluorescence resonance energy transfer imaging and molecular dynamics simulations, we examine the timing and role of conformational events that mediate the release of aa-tRNA from EF-Tu and EF-Tu from the ribosome after GTP hydrolysis. Our investigations reveal that conformational changes in EF-Tu coordinate the rate-limiting passage of aa-tRNA through the accommodation corridor en route to the peptidyl transferase center of the large ribosomal subunit. Experiments using distinct inhibitors of the accommodation process further show that aa-tRNA must at least partially transit the accommodation corridor for EF-Tu⋅GDP to release. aa-tRNAs failing to undergo peptide bond formation at the end of accommodation corridor passage after EF-Tu release can be reengaged by EF-Tu⋅GTP from solution, coupled to GTP hydrolysis. These observations suggest that additional rounds of ternary complex formation can occur on the ribosome during proofreading, particularly when peptide bond formation is slow, which may serve to increase both the rate and fidelity of protein synthesis at the expense of GTP hydrolysis.
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56
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Janzen E, Blanco C, Peng H, Kenchel J, Chen IA. Promiscuous Ribozymes and Their Proposed Role in Prebiotic Evolution. Chem Rev 2020; 120:4879-4897. [PMID: 32011135 PMCID: PMC7291351 DOI: 10.1021/acs.chemrev.9b00620] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
![]()
The ability of enzymes,
including ribozymes, to catalyze side reactions
is believed to be essential to the evolution of novel biochemical
activities. It has been speculated that the earliest ribozymes, whose
emergence marked the origin of life, were low in activity but high
in promiscuity, and that these early ribozymes gave rise to specialized
descendants with higher activity and specificity. Here, we review
the concepts related to promiscuity and examine several cases of highly
promiscuous ribozymes. We consider the evidence bearing on the question
of whether de novo ribozymes would be quantitatively
more promiscuous than later evolved ribozymes or protein enzymes.
We suggest that while de novo ribozymes appear to
be promiscuous in general, they are not obviously more promiscuous
than more highly evolved or active sequences. Promiscuity is a trait
whose value would depend on selective pressures, even during prebiotic
evolution.
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Affiliation(s)
- Evan Janzen
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, California 93109, United States.,Biomolecular Sciences and Engineering Program, University of California, Santa Barbara, Santa Barbara, California 93109, United States
| | - Celia Blanco
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, California 93109, United States
| | - Huan Peng
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, California 93109, United States
| | - Josh Kenchel
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, California 93109, United States.,Biomolecular Sciences and Engineering Program, University of California, Santa Barbara, Santa Barbara, California 93109, United States
| | - Irene A Chen
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, California 93109, United States.,Biomolecular Sciences and Engineering Program, University of California, Santa Barbara, Santa Barbara, California 93109, United States.,Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, Los Angeles, California 90095, United States
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57
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Zada SL, Baruch BB, Simhaev L, Engel H, Fridman M. Chemical Modifications Reduce Auditory Cell Damage Induced by Aminoglycoside Antibiotics. J Am Chem Soc 2020; 142:3077-3087. [PMID: 31958945 DOI: 10.1021/jacs.9b12420] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Although aminoglycoside antibiotics are effective against Gram-negative infections, these drugs often cause irreversible hearing damage. Binding to the decoding site of the eukaryotic ribosomes appears to result in ototoxicity, but there is evidence that other effects are involved. Here, we show how chemical modifications of apramycin and geneticin, considered among the least and most toxic aminoglycosides, respectively, reduce auditory cell damage. Using molecular dynamics simulations, we studied how modified aminoglycosides influence the essential freedom of movement of the decoding site of the ribosome, the region targeted by aminoglycosides. By determining the ratio of a protein translated in mitochondria to that of a protein translated in the cytoplasm, we showed that aminoglycosides can paradoxically elevate rather than reduce protein levels. We showed that certain aminoglycosides induce rapid plasma membrane permeabilization and that this nonribosomal effect can also be reduced through chemical modifications. The results presented suggest a new paradigm for the development of safer aminoglycoside antibiotics.
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Affiliation(s)
- Sivan Louzoun Zada
- School of Chemistry, Raymond and Beverley Sackler Faculty of Exact Sciences , Tel Aviv University , Tel Aviv , Israel , 6997801
| | - Bar Ben Baruch
- School of Chemistry, Raymond and Beverley Sackler Faculty of Exact Sciences , Tel Aviv University , Tel Aviv , Israel , 6997801
| | - Luba Simhaev
- Blavatnik Center for Drug Discovery , Tel Aviv University , Tel Aviv , 6997801 , Israel
| | - Hamutal Engel
- Blavatnik Center for Drug Discovery , Tel Aviv University , Tel Aviv , 6997801 , Israel
| | - Micha Fridman
- School of Chemistry, Raymond and Beverley Sackler Faculty of Exact Sciences , Tel Aviv University , Tel Aviv , Israel , 6997801
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58
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A Structural Basis for Restricted Codon Recognition Mediated by 2-thiocytidine in tRNA Containing a Wobble Position Inosine. J Mol Biol 2020; 432:913-929. [PMID: 31945376 DOI: 10.1016/j.jmb.2019.12.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 11/25/2019] [Accepted: 12/05/2019] [Indexed: 11/20/2022]
Abstract
Three of six arginine codons (CGU, CGC, and CGA) are decoded by two Escherichia coli tRNAArg isoacceptors. The anticodon stem and loop (ASL) domains of tRNAArg1 and tRNAArg2 both contain inosine and 2-methyladenosine modifications at positions 34 (I34) and 37 (m2A37). tRNAArg1 is also modified from cytidine to 2-thiocytidine at position 32 (s2C32). The s2C32 modification is known to negate wobble codon recognition of the rare CGA codon by an unknown mechanism, while still allowing decoding of CGU and CGC. Substitution of s2C32 for C32 in the Saccharomyces cerevisiae tRNAIleIAU anticodon stem and loop domain (ASL) negates wobble decoding of its synonymous A-ending codon, suggesting that this function of s2C at position 32 is a generalizable property. X-ray crystal structures of variously modified ASLArg1ICG and ASLArg2ICG constructs bound to cognate and wobble codons on the ribosome revealed the disruption of a C32-A38 cross-loop interaction but failed to fully explain the means by which s2C32 restricts I34 wobbling. Computational studies revealed that the adoption of a spatially broad inosine-adenosine base pair at the wobble position of the codon cannot be maintained simultaneously with the canonical ASL U-turn motif. C32-A38 cross-loop interactions are required for stability of the anticodon/codon interaction in the ribosomal A-site.
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59
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Warias M, Grubmüller H, Bock LV. tRNA Dissociation from EF-Tu after GTP Hydrolysis: Primary Steps and Antibiotic Inhibition. Biophys J 2020; 118:151-161. [PMID: 31711607 PMCID: PMC6950810 DOI: 10.1016/j.bpj.2019.10.028] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 09/25/2019] [Accepted: 10/22/2019] [Indexed: 11/25/2022] Open
Abstract
In each round of ribosomal translation, the translational GTPase elongation factor Tu (EF-Tu) delivers a transfer RNA (tRNA) to the ribosome. After successful decoding, EF-Tu hydrolyzes GTP, which triggers a conformational change that ultimately results in the release of the tRNA from EF-Tu. To identify the primary steps of these conformational changes and how they are prevented by the antibiotic kirromycin, we employed all-atom explicit-solvent molecular dynamics simulations of the full ribosome-EF-Tu complex. Our results suggest that after GTP hydrolysis and Pi release, the loss of interactions between the nucleotide and the switch 1 loop of EF-Tu allows domain D1 of EF-Tu to rotate relative to domains D2 and D3 and leads to an increased flexibility of the switch 1 loop. This rotation induces a closing of the D1-D3 interface and an opening of the D1-D2 interface. We propose that the opening of the D1-D2 interface, which binds the CCA tail of the tRNA, weakens the crucial EF-Tu-tRNA interactions, which lowers tRNA binding affinity, representing the first step of tRNA release. Kirromycin binds within the D1-D3 interface, sterically blocking its closure, but does not prevent hydrolysis. The resulting increased flexibility of switch 1 explains why it is not resolved in kirromycin-bound structures.
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Affiliation(s)
- Malte Warias
- Theoretical and Computational Biophysics, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Helmut Grubmüller
- Theoretical and Computational Biophysics, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Lars V Bock
- Theoretical and Computational Biophysics, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.
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60
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Thomas EN, Kim KQ, McHugh EP, Marcinkiewicz T, Zaher HS. Alkylative damage of mRNA leads to ribosome stalling and rescue by trans translation in bacteria. eLife 2020; 9:61984. [PMID: 32940602 PMCID: PMC7521929 DOI: 10.7554/elife.61984] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 09/16/2020] [Indexed: 02/06/2023] Open
Abstract
Similar to DNA replication, translation of the genetic code by the ribosome is hypothesized to be exceptionally sensitive to small chemical changes to its template mRNA. Here we show that the addition of common alkylating agents to growing cultures of Escherichia coli leads to the accumulation of several adducts within RNA, including N(1)-methyladenosine (m1A). As expected, the introduction of m1A to model mRNAs was found to reduce the rate of peptide bond formation by three orders of magnitude in a well-defined in vitro system. These observations suggest that alkylative stress is likely to stall translation in vivo and necessitates the activation of ribosome-rescue pathways. Indeed, the addition of alkylation agents was found to robustly activate the transfer-messenger RNA system, even when transcription was inhibited. Our findings suggest that bacteria carefully monitor the chemical integrity of their mRNA and they evolved rescue pathways to cope with its effect on translation.
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Affiliation(s)
- Erica N Thomas
- Department of Biology, Washington University in St. LouisSt. LouisUnited States
| | - Kyusik Q Kim
- Department of Biology, Washington University in St. LouisSt. LouisUnited States
| | - Emily P McHugh
- Department of Biology, Washington University in St. LouisSt. LouisUnited States
| | | | - Hani S Zaher
- Department of Biology, Washington University in St. LouisSt. LouisUnited States
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61
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Structural Bases for the Fitness Cost of the Antibiotic-Resistance and Lethal Mutations at Position 1408 of 16S rRNA. Molecules 2019; 25:molecules25010159. [PMID: 31906077 PMCID: PMC6983231 DOI: 10.3390/molecules25010159] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 12/29/2019] [Accepted: 12/29/2019] [Indexed: 02/04/2023] Open
Abstract
To understand a structural basis for the fitness cost of the A1408G antibiotic-resistance mutation in the ribosomal A-site RNA, we have determined crystal structures of its A1408C and A1408U lethal mutants, and made comparison with previously solved structures of the wild type and the antibiotic-resistant mutant. The A-site RNA containing an asymmetric internal loop functions as a molecular switch to discriminate a single cognate tRNA from several near-cognate tRNAs by its conformational ON/OFF switching. Overall structures of the “off” states of the A1408C/U lethal mutants are very similar to those of the wild type and the A1408G antibiotic-resistant mutant. However, significant differences are found in local base stacking interactions including the functionally important A1492 and A1493 residues. In the wild type and the A1408G antibiotic-resistant mutant “off” states, both adenines are exposed to the solvent region. On the other hand, one of the corresponding adenines of the lethal A1408C/U mutants stay deeply inside their A-site helices by forming a purine-pyrimidine AoC or A-U base pair and is sandwiched between the upper and lower bases. Therefore, the ON/OFF switching might unfavorably occur in the lethal mutants compared to the wild type and the A1408G antibiotic-resistant mutant. It is probable that bacteria manage to acquire antibiotic resistance without losing the function of the A-site molecular switch by mutating the position 1408 only from A to G, but not to pyrimidine base C or U.
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62
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Pavelich IJ, Maehigashi T, Hoffer ED, Ruangprasert A, Miles SJ, Dunham CM. Monomeric YoeB toxin retains RNase activity but adopts an obligate dimeric form for thermal stability. Nucleic Acids Res 2019; 47:10400-10413. [PMID: 31501867 PMCID: PMC6821326 DOI: 10.1093/nar/gkz760] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Revised: 08/13/2019] [Accepted: 08/21/2019] [Indexed: 11/30/2022] Open
Abstract
Chromosomally-encoded toxin-antitoxin complexes are ubiquitous in bacteria and regulate growth through the release of the toxin component typically in a stress-dependent manner. Type II ribosome-dependent toxins adopt a RelE-family RNase fold and inhibit translation by degrading mRNAs while bound to the ribosome. Here, we present biochemical and structural studies of the Escherichia coli YoeB toxin interacting with both a UAA stop and an AAU sense codon in pre- and post-mRNA cleavage states to provide insights into possible mRNA substrate selection. Both mRNAs undergo minimal changes during the cleavage event in contrast to type II ribosome-dependent RelE toxin. Further, the 16S rRNA decoding site nucleotides that monitor the mRNA in the aminoacyl(A) site adopt different orientations depending upon which toxin is present. Although YoeB is a RelE family member, it is the sole ribosome-dependent toxin that is dimeric. We show that engineered monomeric YoeB is active against mRNAs bound to both the small and large subunit. However, the stability of monomeric YoeB is reduced ∼20°C, consistent with potential YoeB activation during heat shock in E. coli as previously demonstrated. These data provide a molecular basis for the ability of YoeB to function in response to thermal stress.
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Affiliation(s)
- Ian J Pavelich
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA.,Emory Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, GA 30322, USA.,Department of Chemistry, Emory University, Atlanta, GA 30322, USA
| | - Tatsuya Maehigashi
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Eric D Hoffer
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA.,Emory Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, GA 30322, USA
| | | | - Stacey J Miles
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Christine M Dunham
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA.,Emory Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, GA 30322, USA
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63
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Battaglia RA, Grigg JC, Ke A. Structural basis for tRNA decoding and aminoacylation sensing by T-box riboregulators. Nat Struct Mol Biol 2019; 26:1106-1113. [PMID: 31740853 PMCID: PMC6953718 DOI: 10.1038/s41594-019-0327-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Accepted: 10/07/2019] [Indexed: 01/31/2023]
Abstract
T-box riboregulators are a class of cis-regulatory RNAs that govern the bacterial response to amino acid starvation by binding, decoding and reading the aminoacylation status of specific transfer RNAs. Here we provide a high-resolution crystal structure of a full-length T-box from Mycobacterium tuberculosis that explains tRNA decoding and aminoacylation sensing by this riboregulator. Overall, the T-box consists of decoding and aminoacylation sensing modules bridged by a rigid pseudoknot structure formed by the mid-region domains. Stem-I and the Stem-II S-turn assemble a claw-like decoding module, while the antiterminator, Stem-III, and the adjacent linker form a tightly interwoven aminoacylation sensing module. The uncharged tRNA is selectively recognized by an unexpected set of favorable contacts from the linker region in the aminoacylation sensing module. A complex structure with a charged tRNA mimic shows that the extra moiety dislodges the linker, which is indicative of the possible chain of events that lead to alternative base-pairing and altered expression output.
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Affiliation(s)
| | - Jason C Grigg
- Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Ailong Ke
- Department of Molecular Biology and Genetics, Ithaca, NY, USA.
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64
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Nürenberg-Goloub E, Tampé R. Ribosome recycling in mRNA translation, quality control, and homeostasis. Biol Chem 2019; 401:47-61. [DOI: 10.1515/hsz-2019-0279] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 10/22/2019] [Indexed: 02/07/2023]
Abstract
Abstract
Protein biosynthesis is a conserved process, essential for life. Ongoing research for four decades has revealed the structural basis and mechanistic details of most protein biosynthesis steps. Numerous pathways and their regulation have recently been added to the translation system describing protein quality control and messenger ribonucleic acid (mRNA) surveillance, ribosome-associated protein folding and post-translational modification as well as human disorders associated with mRNA and ribosome homeostasis. Thus, translation constitutes a key regulatory process placing the ribosome as a central hub at the crossover of numerous cellular pathways. Here, we describe the role of ribosome recycling by ATP-binding cassette sub-family E member 1 (ABCE1) as a crucial regulatory step controlling the biogenesis of functional proteins and the degradation of aberrant nascent chains in quality control processes.
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Affiliation(s)
- Elina Nürenberg-Goloub
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt , Max-von-Laue-Str. 9 , D-60438 Frankfurt/Main , Germany
| | - Robert Tampé
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt , Max-von-Laue-Str. 9 , D-60438 Frankfurt/Main , Germany
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65
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Thomas EN, Simms CL, Keedy HE, Zaher HS. Insights into the base-pairing preferences of 8-oxoguanosine on the ribosome. Nucleic Acids Res 2019; 47:9857-9870. [PMID: 31400119 PMCID: PMC6765139 DOI: 10.1093/nar/gkz701] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 07/26/2019] [Accepted: 07/30/2019] [Indexed: 02/06/2023] Open
Abstract
Of the four bases, guanine is the most susceptible to oxidation, which results in the formation of 8-oxoguanine (8-oxoG). In protein-free DNA, 8-oxodG adopts the syn conformation more frequently than the anti one. In the syn conformation, 8-oxodG base pairs with dA. The equilibrium between the anti and syn conformations of the adduct are known to be altered by the enzyme recognizing 8-oxodG. We previously showed that 8-oxoG in mRNA severely disrupts tRNA selection, but the underlying mechanism for these effects was not addressed. Here, we use miscoding antibiotics and ribosome mutants to probe how 8-oxoG interacts with the tRNA anticodon in the decoding center. Addition of antibiotics and introduction of error-inducing mutations partially suppressed the effects of 8-oxoG. Under these conditions, rates and/or endpoints of peptide-bond formation for the cognate (8-oxoG•C) and near-cognate (8-oxoG•A) aminoacyl-tRNAs increased. In contrast, the antibiotics had little effect on other mismatches, suggesting that the lesion restricts the nucleotide from forming other interactions. Our findings suggest that 8-oxoG predominantly adopts the syn conformation in the A site. However, its ability to base pair with adenosine in this conformation is not sufficient to promote the necessary structural changes for tRNA selection to proceed.
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Affiliation(s)
- Erica N Thomas
- Department of Biology, Washington University in St. Louis, Campus Box 1137, One Brookings Drive, St. Louis, MO 63130, USA
| | - Carrie L Simms
- Department of Biology, Washington University in St. Louis, Campus Box 1137, One Brookings Drive, St. Louis, MO 63130, USA
| | - Hannah E Keedy
- Department of Biology, Washington University in St. Louis, Campus Box 1137, One Brookings Drive, St. Louis, MO 63130, USA
| | - Hani S Zaher
- Department of Biology, Washington University in St. Louis, Campus Box 1137, One Brookings Drive, St. Louis, MO 63130, USA
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66
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McMahon M, Contreras A, Holm M, Uechi T, Forester CM, Pang X, Jackson C, Calvert ME, Chen B, Quigley DA, Luk JM, Kelley RK, Gordan JD, Gill RM, Blanchard SC, Ruggero D. A single H/ACA small nucleolar RNA mediates tumor suppression downstream of oncogenic RAS. eLife 2019; 8:48847. [PMID: 31478838 PMCID: PMC6776443 DOI: 10.7554/elife.48847] [Citation(s) in RCA: 83] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Accepted: 09/02/2019] [Indexed: 12/19/2022] Open
Abstract
Small nucleolar RNAs (snoRNAs) are a diverse group of non-coding RNAs that direct chemical modifications at specific residues on other RNA molecules, primarily on ribosomal RNA (rRNA). SnoRNAs are altered in several cancers; however, their role in cell homeostasis as well as in cellular transformation remains poorly explored. Here, we show that specific subsets of snoRNAs are differentially regulated during the earliest cellular response to oncogenic RASG12V expression. We describe a novel function for one H/ACA snoRNA, SNORA24, which guides two pseudouridine modifications within the small ribosomal subunit, in RAS-induced senescence in vivo. We find that in mouse models, loss of Snora24 cooperates with RASG12V to promote the development of liver cancer that closely resembles human steatohepatitic hepatocellular carcinoma (HCC). From a clinical perspective, we further show that human HCCs with low SNORA24 expression display increased lipid content and are associated with poor patient survival. We next asked whether ribosomes lacking SNORA24-guided pseudouridine modifications on 18S rRNA have alterations in their biophysical properties. Single-molecule Fluorescence Resonance Energy Transfer (FRET) analyses revealed that these ribosomes exhibit perturbations in aminoacyl-transfer RNA (aa-tRNA) selection and altered pre-translocation ribosome complex dynamics. Furthermore, we find that HCC cells lacking SNORA24-guided pseudouridine modifications have increased translational miscoding and stop codon readthrough frequencies. These findings highlight a role for specific snoRNAs in safeguarding against oncogenic insult and demonstrate a functional link between H/ACA snoRNAs regulated by RAS and the biophysical properties of ribosomes in cancer.
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Affiliation(s)
- Mary McMahon
- Helen Diller Family Comprehensive Cancer Center, Department of Urology, University of California, San Francisco, San Francisco, United States
| | - Adrian Contreras
- Helen Diller Family Comprehensive Cancer Center, Department of Urology, University of California, San Francisco, San Francisco, United States
| | - Mikael Holm
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, United States
| | - Tamayo Uechi
- Helen Diller Family Comprehensive Cancer Center, Department of Urology, University of California, San Francisco, San Francisco, United States
| | - Craig M Forester
- Helen Diller Family Comprehensive Cancer Center, Department of Urology, University of California, San Francisco, San Francisco, United States.,Division of Pediatric Allergy, Immunology & Bone Marrow Transplantation, University of California, San Francisco, San Francisco, United States
| | - Xiaming Pang
- Helen Diller Family Comprehensive Cancer Center, Department of Urology, University of California, San Francisco, San Francisco, United States
| | - Cody Jackson
- Gladstone Histology and Light Microscopy Core, Gladstone Institutes, San Francisco, United States
| | - Meredith E Calvert
- Gladstone Histology and Light Microscopy Core, Gladstone Institutes, San Francisco, United States
| | - Bin Chen
- Department of Pediatrics and Human Development, Michigan State University, Grand Rapids, United States.,Department of Pharmacology and Toxicology, Michigan State University, Grand Rapids, United States
| | - David A Quigley
- Helen Diller Family Comprehensive Cancer Center and Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, United States
| | - John M Luk
- Arbele Corporation, Seattle, United States
| | - R Kate Kelley
- Helen Diller Family Comprehensive Cancer Center, Department of Medicine, University of California, San Francisco, San Francisco, United States
| | - John D Gordan
- Helen Diller Family Comprehensive Cancer Center, Department of Medicine, University of California, San Francisco, San Francisco, United States
| | - Ryan M Gill
- Department of Pathology, University of California, San Francisco, San Francisco, United States
| | - Scott C Blanchard
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, United States
| | - Davide Ruggero
- Helen Diller Family Comprehensive Cancer Center, Department of Urology, University of California, San Francisco, San Francisco, United States.,Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, United States
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67
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Weisser M, Ban N. Extensions, Extra Factors, and Extreme Complexity: Ribosomal Structures Provide Insights into Eukaryotic Translation. Cold Spring Harb Perspect Biol 2019; 11:11/9/a032367. [PMID: 31481454 DOI: 10.1101/cshperspect.a032367] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Although the basic aspects of protein synthesis are preserved in all kingdoms of life, there are many important structural and functional differences between bacterial and the more complex eukaryotic ribosomes. High-resolution cryo-electron microscopy (cryo-EM) and X-ray crystallography structures of eukaryotic ribosomes have revealed the complex architectures of eukaryotic ribosomes and species-specific variations in protein and ribosomal RNA (rRNA) extensions. They also enabled structural studies of a range of eukaryotic ribosomal complexes involved in translation initiation, elongation, and termination, revealing unique mechanistic features of the eukaryotic translation process, especially with respect to the identification and recognition of translation start and stop codons on messenger RNAs (mRNAs). Most recently, structural biology has provided insights into the eukaryotic ribosomal biogenesis pathway by visualizing several of its complex intermediates. This review highlights the past decade's structural work on eukaryotic ribosomes and its implications on our understanding of eukaryotic translation.
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Affiliation(s)
- Melanie Weisser
- Institute of Molecular Biology and Biophysics, Department of Biology, ETH Zürich, 8093 Zürich, Switzerland
| | - Nenad Ban
- Institute of Molecular Biology and Biophysics, Department of Biology, ETH Zürich, 8093 Zürich, Switzerland
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68
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Hoffer ED, Maehigashi T, Fredrick K, Dunham CM. Ribosomal ambiguity (ram) mutations promote the open (off) to closed (on) transition and thereby increase miscoding. Nucleic Acids Res 2019; 47:1557-1563. [PMID: 30476222 PMCID: PMC6379664 DOI: 10.1093/nar/gky1178] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 10/31/2018] [Accepted: 11/05/2018] [Indexed: 01/18/2023] Open
Abstract
Decoding is thought to be governed by a conformational transition in the ribosome—open (off) to closed (on)—that occurs upon codon–anticodon pairing in the A site. Ribosomal ambiguity (ram) mutations increase miscoding and map to disparate regions, consistent with a role for ribosome dynamics in decoding, yet precisely how these mutations act has been unclear. Here, we solved crystal structures of 70S ribosomes harboring 16S ram mutations G299A and G347U in the absence A-site tRNA (A-tRNA) and in the presence of a near-cognate anticodon stem-loop (ASL). In the absence of an A-tRNA, each of the mutant ribosomes exhibits a partially closed (on) state. In the 70S-G347U structure, the 30S shoulder is rotated inward and intersubunit bridge B8 is disrupted. In the 70S-G299A structure, the 30S shoulder is rotated inward and decoding nucleotide G530 flips into the anti conformation. Both of these mutant ribosomes adopt the fully closed (on) conformation in the presence of near-cognate A-tRNA, just as they do with cognate A-tRNA. Thus, these ram mutations act by promoting the open (off) to closed (on) transition, albeit in somewhat distinct ways. This work reveals the functional importance of 30S shoulder rotation for productive aminoacylated-tRNA incorporation.
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Affiliation(s)
- Eric D Hoffer
- Department of Biochemistry and Emory Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Tatsuya Maehigashi
- Department of Biochemistry and Emory Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Kurt Fredrick
- Department of Microbiology and Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA
- Correspondence may also be addressed to Kurt Fredrick. Tel: +1 614 292 6679; Fax: +1 614 292 8120;
| | - Christine M Dunham
- Department of Biochemistry and Emory Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, GA 30322, USA
- To whom correspondence should be addressed. Tel: +1 404 712 1756; Fax: +1 404 727 2738; E-mail:
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69
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Berg MD, Giguere DJ, Dron JS, Lant JT, Genereaux J, Liao C, Wang J, Robinson JF, Gloor GB, Hegele RA, O'Donoghue P, Brandl CJ. Targeted sequencing reveals expanded genetic diversity of human transfer RNAs. RNA Biol 2019; 16:1574-1585. [PMID: 31407949 PMCID: PMC6779403 DOI: 10.1080/15476286.2019.1646079] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Transfer RNAs are required to translate genetic information into proteins as well as regulate other cellular processes. Nucleotide changes in tRNAs can result in loss or gain of function that impact the composition and fidelity of the proteome. Despite links between tRNA variation and disease, the importance of cytoplasmic tRNA variation has been overlooked. Using a custom capture panel, we sequenced 605 human tRNA-encoding genes from 84 individuals. We developed a bioinformatic pipeline that allows more accurate tRNA read mapping and identifies multiple polymorphisms occurring within the same variant. Our analysis identified 522 unique tRNA-encoding sequences that differed from the reference genome from 84 individuals. Each individual had ~66 tRNA variants including nine variants found in less than 5% of our sample group. Variants were identified throughout the tRNA structure with 17% predicted to enhance function. Eighteen anticodon mutants were identified including potentially mistranslating tRNAs; e.g., a tRNASer that decodes Phe codons. Similar engineered tRNA variants were previously shown to inhibit cell growth, increase apoptosis and induce the unfolded protein response in mammalian cell cultures and chick embryos. Our analysis shows that human tRNA variation has been underestimated. We conclude that the large number of tRNA genes provides a buffer enabling the emergence of variants, some of which could contribute to disease.
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Affiliation(s)
- Matthew D Berg
- Department of Biochemistry, The University of Western Ontario , London , ON , Canada
| | - Daniel J Giguere
- Department of Biochemistry, The University of Western Ontario , London , ON , Canada
| | - Jacqueline S Dron
- Department of Biochemistry, The University of Western Ontario , London , ON , Canada.,Robarts Research Institute, The University of Western Ontario , London , ON , Canada
| | - Jeremy T Lant
- Department of Biochemistry, The University of Western Ontario , London , ON , Canada
| | - Julie Genereaux
- Department of Biochemistry, The University of Western Ontario , London , ON , Canada
| | - Calwing Liao
- Department of Biochemistry, The University of Western Ontario , London , ON , Canada.,Robarts Research Institute, The University of Western Ontario , London , ON , Canada
| | - Jian Wang
- Robarts Research Institute, The University of Western Ontario , London , ON , Canada
| | - John F Robinson
- Robarts Research Institute, The University of Western Ontario , London , ON , Canada
| | - Gregory B Gloor
- Department of Biochemistry, The University of Western Ontario , London , ON , Canada
| | - Robert A Hegele
- Department of Biochemistry, The University of Western Ontario , London , ON , Canada.,Robarts Research Institute, The University of Western Ontario , London , ON , Canada.,Department of Medicine, The University of Western Ontario , London , ON , Canada
| | - Patrick O'Donoghue
- Department of Biochemistry, The University of Western Ontario , London , ON , Canada.,Department of Chemistry, The University of Western Ontario , London , ON , Canada
| | - Christopher J Brandl
- Department of Biochemistry, The University of Western Ontario , London , ON , Canada
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70
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Fislage M, Zhang J, Brown ZP, Mandava CS, Sanyal S, Ehrenberg M, Frank J. Cryo-EM shows stages of initial codon selection on the ribosome by aa-tRNA in ternary complex with GTP and the GTPase-deficient EF-TuH84A. Nucleic Acids Res 2019; 46:5861-5874. [PMID: 29733411 PMCID: PMC6009598 DOI: 10.1093/nar/gky346] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Accepted: 04/30/2018] [Indexed: 11/25/2022] Open
Abstract
The GTPase EF-Tu in ternary complex with GTP and aminoacyl-tRNA (aa-tRNA) promotes rapid and accurate delivery of cognate aa-tRNAs to the ribosomal A site. Here we used cryo-EM to study the molecular origins of the accuracy of ribosome-aided recognition of a cognate ternary complex and the accuracy-amplifying role of the monitoring bases A1492, A1493 and G530 of the 16S rRNA. We used the GTPase-deficient EF-Tu variant H84A with native GTP, rather than non-cleavable GTP analogues, to trap a near-cognate ternary complex in high-resolution ribosomal complexes of varying codon-recognition accuracy. We found that ribosome complexes trapped by GTPase-deficicent ternary complex due to the presence of EF-TuH84A or non-cleavable GTP analogues have very similar structures. We further discuss speed and accuracy of initial aa-tRNA selection in terms of conformational changes of aa-tRNA and stepwise activation of the monitoring bases at the decoding center of the ribosome.
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Affiliation(s)
- Marcus Fislage
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Jingji Zhang
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA.,Department of Cell and Molecular Biology, Uppsala University, Uppsala 75124, Sweden
| | - Zuben Patrick Brown
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | | | - Suparna Sanyal
- Department of Cell and Molecular Biology, Uppsala University, Uppsala 75124, Sweden
| | - Måns Ehrenberg
- Department of Cell and Molecular Biology, Uppsala University, Uppsala 75124, Sweden
| | - Joachim Frank
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA.,Department of Biological Sciences, Columbia University, New York, NY, USA
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71
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Antoine L, Wolff P, Westhof E, Romby P, Marzi S. Mapping post-transcriptional modifications in Staphylococcus aureus tRNAs by nanoLC/MSMS. Biochimie 2019; 164:60-69. [PMID: 31295507 DOI: 10.1016/j.biochi.2019.07.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Accepted: 07/03/2019] [Indexed: 02/06/2023]
Abstract
RNA modifications are involved in numerous biological processes. These modifications are constitutive or modulated in response to adaptive processes and can impact RNA base-pairing formation, protein recognition, RNA structure and stability. tRNAs are the most abundantly modified RNA molecules. Analysis of the roles of their modifications in response to stress, environmental changes, and infections caused by pathogens, has fueled new research areas. Nevertheless, the detection of modified nucleotides in RNAs is still a challenging task. We present here a reliable method to identify and localize tRNA modifications, which was applied to the human pathogenic bacteria, Staphyloccocus aureus. The method is based on a separation of tRNA species on a two-dimensional polyacrylamide gel electrophoresis followed by nano liquid chromatography-mass spectrometry. We provided a list of modifications mapped on 25 out of the 40 tRNA species (one isoacceptor for each amino acid). This method can be easily used to monitor the dynamics of tRNA modifications in S. aureus in response to stress adaptation and during infection of the host, a relatively unexplored field.
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Affiliation(s)
- Laura Antoine
- Université de Strasbourg, CNRS, Architecture et Réactivité de L'ARN, UPR 9002, F-67000, Strasbourg, France
| | - Philippe Wolff
- Université de Strasbourg, CNRS, Architecture et Réactivité de L'ARN, UPR 9002, F-67000, Strasbourg, France; Plateforme Protéomique Strasbourg Esplanade, CNRS, FR1589, F-67000, Strasbourg, France
| | - Eric Westhof
- Université de Strasbourg, CNRS, Architecture et Réactivité de L'ARN, UPR 9002, F-67000, Strasbourg, France
| | - Pascale Romby
- Université de Strasbourg, CNRS, Architecture et Réactivité de L'ARN, UPR 9002, F-67000, Strasbourg, France
| | - Stefano Marzi
- Université de Strasbourg, CNRS, Architecture et Réactivité de L'ARN, UPR 9002, F-67000, Strasbourg, France.
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72
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Zhang J, Pavlov MY, Ehrenberg M. Accuracy of genetic code translation and its orthogonal corruption by aminoglycosides and Mg2+ ions. Nucleic Acids Res 2019; 46:1362-1374. [PMID: 29267976 PMCID: PMC5814885 DOI: 10.1093/nar/gkx1256] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2017] [Accepted: 12/13/2017] [Indexed: 01/24/2023] Open
Abstract
We studied the effects of aminoglycosides and changing Mg2+ ion concentration on the accuracy of initial codon selection by aminoacyl-tRNA in ternary complex with elongation factor Tu and GTP (T3) on mRNA programmed ribosomes. Aminoglycosides decrease the accuracy by changing the equilibrium constants of 'monitoring bases' A1492, A1493 and G530 in 16S rRNA in favor of their 'activated' state by large, aminoglycoside-specific factors, which are the same for cognate and near-cognate codons. Increasing Mg2+ concentration decreases the accuracy by slowing dissociation of T3 from its initial codon- and aminoglycoside-independent binding state on the ribosome. The distinct accuracy-corrupting mechanisms for aminoglycosides and Mg2+ ions prompted us to re-interpret previous biochemical experiments and functional implications of existing high resolution ribosome structures. We estimate the upper thermodynamic limit to the accuracy, the 'intrinsic selectivity' of the ribosome. We conclude that aminoglycosides do not alter the intrinsic selectivity but reduce the fraction of it that is expressed as the accuracy of initial selection. We suggest that induced fit increases the accuracy and speed of codon reading at unaltered intrinsic selectivity of the ribosome.
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Affiliation(s)
- Jingji Zhang
- Department of Cell and Molecular Biology, Uppsala University, Husargatan 3, Box 596, Uppsala 75124, Sweden
| | - Michael Y Pavlov
- Department of Cell and Molecular Biology, Uppsala University, Husargatan 3, Box 596, Uppsala 75124, Sweden
| | - Måns Ehrenberg
- Department of Cell and Molecular Biology, Uppsala University, Husargatan 3, Box 596, Uppsala 75124, Sweden
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73
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Larsen KP, Choi J, Prabhakar A, Puglisi EV, Puglisi JD. Relating Structure and Dynamics in RNA Biology. Cold Spring Harb Perspect Biol 2019; 11:11/7/a032474. [PMID: 31262948 DOI: 10.1101/cshperspect.a032474] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Recent advances in structural biology methods have enabled a surge in the number of RNA and RNA-protein assembly structures available at atomic or near-atomic resolution. These complexes are often trapped in discrete conformational states that exist along a mechanistic pathway. Single-molecule fluorescence methods provide temporal resolution to elucidate the dynamic mechanisms of processes involving complex RNA and RNA-protein assemblies, but interpretation of such data often requires previous structural knowledge. Here we highlight how single-molecule tools can directly complement structural approaches for two processes--translation and reverse transcription-to provide a dynamic view of molecular function.
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Affiliation(s)
- Kevin P Larsen
- Department of Structural Biology, Stanford University School of Medicine, Stanford, California 94305.,Biophysics Program, Stanford University, Stanford, California 94305
| | - Junhong Choi
- Department of Structural Biology, Stanford University School of Medicine, Stanford, California 94305.,Department of Applied Physics, Stanford University, Stanford, California 94305
| | - Arjun Prabhakar
- Department of Structural Biology, Stanford University School of Medicine, Stanford, California 94305.,Biophysics Program, Stanford University, Stanford, California 94305
| | - Elisabetta Viani Puglisi
- Department of Structural Biology, Stanford University School of Medicine, Stanford, California 94305
| | - Joseph D Puglisi
- Department of Structural Biology, Stanford University School of Medicine, Stanford, California 94305
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74
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O'Sullivan ME, Poitevin F, Sierra RG, Gati C, Dao EH, Rao Y, Aksit F, Ciftci H, Corsepius N, Greenhouse R, Hayes B, Hunter MS, Liang M, McGurk A, Mbgam P, Obrinsky T, Pardo-Avila F, Seaberg MH, Cheng AG, Ricci AJ, DeMirci H. Aminoglycoside ribosome interactions reveal novel conformational states at ambient temperature. Nucleic Acids Res 2019; 46:9793-9804. [PMID: 30113694 PMCID: PMC6182148 DOI: 10.1093/nar/gky693] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Accepted: 07/19/2018] [Indexed: 11/21/2022] Open
Abstract
The bacterial 30S ribosomal subunit is a primary antibiotic target. Despite decades of discovery, the mechanisms by which antibiotic binding induces ribosomal dysfunction are not fully understood. Ambient temperature crystallographic techniques allow more biologically relevant investigation of how local antibiotic binding site interactions trigger global subunit rearrangements that perturb protein synthesis. Here, the structural effects of 2-deoxystreptamine (paromomycin and sisomicin), a novel sisomicin derivative, N1-methyl sulfonyl sisomicin (N1MS) and the non-deoxystreptamine (streptomycin) aminoglycosides on the ribosome at ambient and cryogenic temperatures were examined. Comparative studies led to three main observations. First, individual aminoglycoside–ribosome interactions in the decoding center were similar for cryogenic versus ambient temperature structures. Second, analysis of a highly conserved GGAA tetraloop of h45 revealed aminoglycoside-specific conformational changes, which are affected by temperature only for N1MS. We report the h44–h45 interface in varying states, i.e. engaged, disengaged and in equilibrium. Third, we observe aminoglycoside-induced effects on 30S domain closure, including a novel intermediary closure state, which is also sensitive to temperature. Analysis of three ambient and five cryogenic crystallography datasets reveal a correlation between h44–h45 engagement and domain closure. These observations illustrate the role of ambient temperature crystallography in identifying dynamic mechanisms of ribosomal dysfunction induced by local drug-binding site interactions. Together, these data identify tertiary ribosomal structural changes induced by aminoglycoside binding that provides functional insight and targets for drug design.
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Affiliation(s)
- Mary E O'Sullivan
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Palo Alto, CA, USA, 94305
| | - Frédéric Poitevin
- Department of Structural Biology, Stanford University, Palo Alto, CA, USA, 94305.,Stanford PULSE Institute, SLAC National Laboratory, Menlo Park, CA, USA, 94025
| | - Raymond G Sierra
- Linac Coherent Light Source, SLAC National Laboratory, Menlo Park, CA, USA, 94025
| | - Cornelius Gati
- Department of Structural Biology, Stanford University, Palo Alto, CA, USA, 94305.,Biosciences Division, SLAC National Laboratory, Menlo Park, CA, USA, 94025
| | - E Han Dao
- Stanford PULSE Institute, SLAC National Laboratory, Menlo Park, CA, USA, 94025
| | - Yashas Rao
- Linac Coherent Light Source, SLAC National Laboratory, Menlo Park, CA, USA, 94025
| | - Fulya Aksit
- Linac Coherent Light Source, SLAC National Laboratory, Menlo Park, CA, USA, 94025
| | - Halilibrahim Ciftci
- Linac Coherent Light Source, SLAC National Laboratory, Menlo Park, CA, USA, 94025
| | - Nicholas Corsepius
- Department of Structural Biology, Stanford University, Palo Alto, CA, USA, 94305
| | - Robert Greenhouse
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Palo Alto, CA, USA, 94305
| | - Brandon Hayes
- Linac Coherent Light Source, SLAC National Laboratory, Menlo Park, CA, USA, 94025
| | - Mark S Hunter
- Linac Coherent Light Source, SLAC National Laboratory, Menlo Park, CA, USA, 94025
| | - Mengling Liang
- Linac Coherent Light Source, SLAC National Laboratory, Menlo Park, CA, USA, 94025
| | - Alex McGurk
- Linac Coherent Light Source, SLAC National Laboratory, Menlo Park, CA, USA, 94025
| | - Paul Mbgam
- Linac Coherent Light Source, SLAC National Laboratory, Menlo Park, CA, USA, 94025
| | - Trevor Obrinsky
- Linac Coherent Light Source, SLAC National Laboratory, Menlo Park, CA, USA, 94025
| | - Fátima Pardo-Avila
- Department of Structural Biology, Stanford University, Palo Alto, CA, USA, 94305
| | - Matthew H Seaberg
- Linac Coherent Light Source, SLAC National Laboratory, Menlo Park, CA, USA, 94025
| | - Alan G Cheng
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Palo Alto, CA, USA, 94305
| | - Anthony J Ricci
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Palo Alto, CA, USA, 94305
| | - Hasan DeMirci
- Department of Structural Biology, Stanford University, Palo Alto, CA, USA, 94305.,Stanford PULSE Institute, SLAC National Laboratory, Menlo Park, CA, USA, 94025.,Biosciences Division, SLAC National Laboratory, Menlo Park, CA, USA, 94025
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75
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Santos M, Fidalgo A, Varanda AS, Oliveira C, Santos MAS. tRNA Deregulation and Its Consequences in Cancer. Trends Mol Med 2019; 25:853-865. [PMID: 31248782 DOI: 10.1016/j.molmed.2019.05.011] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 05/24/2019] [Accepted: 05/28/2019] [Indexed: 02/06/2023]
Abstract
The expression of transfer RNAs (tRNAs) is deregulated in cancer cells but the mechanisms and functional meaning of such deregulation are poorly understood. The proteome of cancer cells is not fully encoded by their transcriptome, however, the contribution of mRNA translation to such diversity remains to be elucidated. We review data supporting the hypothesis that tRNA expression deregulation and translational error rate is an important contributor to proteome diversity and cell population heterogeneity, genome instability, and drug resistance in tumors. This hypothesis is aligned with recent data in various model organisms, showing unanticipated adaptive roles of translational errors (adaptive mistranslation), expression control of specific gene subsets by tRNAs, and proteome diversification by elevation of translational error rates in tumors.
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Affiliation(s)
- Mafalda Santos
- Expression Regulation in Cancer, Instituto de Investigação e Inovação em Saúde, University of Porto, Portugal; Institute of Molecular Pathology and Immunology University of Porto (IPATIMUP), Porto, Portugal; Department of Medical Sciences and Institute of Biomedicine - iBiMED, University of Aveiro, Aveiro, Portugal
| | - Ana Fidalgo
- Department of Medical Sciences and Institute of Biomedicine - iBiMED, University of Aveiro, Aveiro, Portugal
| | - A Sofia Varanda
- Expression Regulation in Cancer, Instituto de Investigação e Inovação em Saúde, University of Porto, Portugal; Institute of Molecular Pathology and Immunology University of Porto (IPATIMUP), Porto, Portugal; Department of Medical Sciences and Institute of Biomedicine - iBiMED, University of Aveiro, Aveiro, Portugal
| | - Carla Oliveira
- Expression Regulation in Cancer, Instituto de Investigação e Inovação em Saúde, University of Porto, Portugal; Institute of Molecular Pathology and Immunology University of Porto (IPATIMUP), Porto, Portugal; Department of Pathology, Medical Faculty of Porto, Porto, Portugal.
| | - Manuel A S Santos
- Department of Medical Sciences and Institute of Biomedicine - iBiMED, University of Aveiro, Aveiro, Portugal.
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76
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Choi J, Grosely R, Prabhakar A, Lapointe CP, Wang J, Puglisi JD. How Messenger RNA and Nascent Chain Sequences Regulate Translation Elongation. Annu Rev Biochem 2019; 87:421-449. [PMID: 29925264 DOI: 10.1146/annurev-biochem-060815-014818] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Translation elongation is a highly coordinated, multistep, multifactor process that ensures accurate and efficient addition of amino acids to a growing nascent-peptide chain encoded in the sequence of translated messenger RNA (mRNA). Although translation elongation is heavily regulated by external factors, there is clear evidence that mRNA and nascent-peptide sequences control elongation dynamics, determining both the sequence and structure of synthesized proteins. Advances in methods have driven experiments that revealed the basic mechanisms of elongation as well as the mechanisms of regulation by mRNA and nascent-peptide sequences. In this review, we highlight how mRNA and nascent-peptide elements manipulate the translation machinery to alter the dynamics and pathway of elongation.
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Affiliation(s)
- Junhong Choi
- Department of Structural Biology, Stanford University School of Medicine, Stanford, California 94305-5126, USA; , , , , , .,Department of Applied Physics, Stanford University, Stanford, California 94305-4090, USA
| | - Rosslyn Grosely
- Department of Structural Biology, Stanford University School of Medicine, Stanford, California 94305-5126, USA; , , , , ,
| | - Arjun Prabhakar
- Department of Structural Biology, Stanford University School of Medicine, Stanford, California 94305-5126, USA; , , , , , .,Program in Biophysics, Stanford University, Stanford, California 94305, USA
| | - Christopher P Lapointe
- Department of Structural Biology, Stanford University School of Medicine, Stanford, California 94305-5126, USA; , , , , ,
| | - Jinfan Wang
- Department of Structural Biology, Stanford University School of Medicine, Stanford, California 94305-5126, USA; , , , , ,
| | - Joseph D Puglisi
- Department of Structural Biology, Stanford University School of Medicine, Stanford, California 94305-5126, USA; , , , , ,
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77
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Importance of potassium ions for ribosome structure and function revealed by long-wavelength X-ray diffraction. Nat Commun 2019; 10:2519. [PMID: 31175275 PMCID: PMC6555806 DOI: 10.1038/s41467-019-10409-4] [Citation(s) in RCA: 103] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 05/06/2019] [Indexed: 11/08/2022] Open
Abstract
The ribosome, the largest RNA-containing macromolecular machinery in cells, requires metal ions not only to maintain its three-dimensional fold but also to perform protein synthesis. Despite the vast biochemical data regarding the importance of metal ions for efficient protein synthesis and the increasing number of ribosome structures solved by X-ray crystallography or cryo-electron microscopy, the assignment of metal ions within the ribosome remains elusive due to methodological limitations. Here we present extensive experimental data on the potassium composition and environment in two structures of functional ribosome complexes obtained by measurement of the potassium anomalous signal at the K-edge, derived from long-wavelength X-ray diffraction data. We elucidate the role of potassium ions in protein synthesis at the three-dimensional level, most notably, in the environment of the ribosome functional decoding and peptidyl transferase centers. Our data expand the fundamental knowledge of the mechanism of ribosome function and structural integrity.
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78
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Lind C, Esguerra M, Jespers W, Satpati P, Gutierrez-de-Terán H, Åqvist J. Free energy calculations of RNA interactions. Methods 2019; 162-163:85-95. [DOI: 10.1016/j.ymeth.2019.02.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 02/01/2019] [Accepted: 02/15/2019] [Indexed: 01/19/2023] Open
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79
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Guo P, Lam SL. Unprecedented hydrophobic stabilizations from a reverse wobble T·T mispair in DNA minidumbbell. J Biomol Struct Dyn 2019; 38:1946-1953. [DOI: 10.1080/07391102.2019.1621211] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Pei Guo
- Department of Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong
| | - Sik Lok Lam
- Department of Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong
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80
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Pavlov MY, Ehrenberg M. Substrate-Induced Formation of Ribosomal Decoding Center for Accurate and Rapid Genetic Code Translation. Annu Rev Biophys 2019; 47:525-548. [PMID: 29792818 DOI: 10.1146/annurev-biophys-060414-034148] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Accurate translation of genetic information is crucial for synthesis of functional proteins in all organisms. We use recent experimental data to discuss how induced fit affects accuracy of initial codon selection on the ribosome by aminoacyl transfer RNA in ternary complex ( T3) with elongation factor Tu (EF-Tu) and guanosine-5'-triphosphate (GTP). We define actual accuracy ([Formula: see text]) of a particular protein synthesis system as its current accuracy and the effective selectivity ([Formula: see text]) as [Formula: see text] in the limit of zero ribosomal binding affinity for T3. Intrinsic selectivity ([Formula: see text]), defined as the upper thermodynamic limit of [Formula: see text], is determined by the free energy difference between near-cognate and cognate T3 in the pre-GTP hydrolysis state on the ribosome. [Formula: see text] is much larger than [Formula: see text], suggesting the possibility of a considerable increase in [Formula: see text] and [Formula: see text] at negligible kinetic cost. Induced fit increases [Formula: see text] and [Formula: see text] without affecting [Formula: see text], and aminoglycoside antibiotics reduce [Formula: see text] and [Formula: see text] at unaltered [Formula: see text].
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Affiliation(s)
- Michael Y Pavlov
- Department of Cell and Molecular Biology, Uppsala University, Uppsala 75124, Sweden;
| | - Måns Ehrenberg
- Department of Cell and Molecular Biology, Uppsala University, Uppsala 75124, Sweden;
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81
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Westhof E, Yusupov M, Yusupova G. The multiple flavors of GoU pairs in RNA. J Mol Recognit 2019; 32:e2782. [PMID: 31033092 PMCID: PMC6617799 DOI: 10.1002/jmr.2782] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 03/02/2019] [Accepted: 03/14/2019] [Indexed: 11/10/2022]
Abstract
Wobble GU pairs (or GoU) occur frequently within double‐stranded RNA helices interspersed within the standard G═C and A─U Watson‐Crick pairs. However, other types of GoU pairs interacting on their Watson‐Crick edges have been observed. The structural and functional roles of such alternative GoU pairs are surprisingly diverse and reflect the various pairings G and U can form by exploiting all the subtleties of their electronic configurations. Here, the structural characteristics of the GoU pairs are updated following the recent crystallographic structures of functional ribosomal complexes and the development in our understanding of ribosomal translation.
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Affiliation(s)
- Eric Westhof
- Architecture et Réactivité de l'ARN, Institut de biologie moléculaire et cellulaire du CNRS, Université de Strasbourg, Strasbourg, France
| | - Marat Yusupov
- Department of Integrated Structural Biology, Institute of Genetics and Molecular and Cellular Biology, INSERM, U964, CNRS, UMR7104, Université de Strasbourg, Illkirch, France
| | - Gulnara Yusupova
- Department of Integrated Structural Biology, Institute of Genetics and Molecular and Cellular Biology, INSERM, U964, CNRS, UMR7104, Université de Strasbourg, Illkirch, France
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82
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Nguyen HA, Hoffer ED, Dunham CM. Importance of a tRNA anticodon loop modification and a conserved, noncanonical anticodon stem pairing in tRNACGGProfor decoding. J Biol Chem 2019; 294:5281-5291. [PMID: 30782843 PMCID: PMC6462517 DOI: 10.1074/jbc.ra119.007410] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 02/13/2019] [Indexed: 01/15/2023] Open
Abstract
Modification of anticodon nucleotides allows tRNAs to decode multiple codons, expanding the genetic code. Additionally, modifications located in the anticodon loop, outside the anticodon itself, stabilize tRNA–codon interactions, increasing decoding fidelity. Anticodon loop nucleotide 37 is 3′ to the anticodon and, in tRNA CGG Pro , is methylated at the N1 position in its nucleobase (m1G37). The m1G37 modification in tRNA CGG Pro stabilizes its interaction with the codon and maintains the mRNA frame. However, it is unclear how m1G37 affects binding at the decoding center to both cognate and +1 slippery codons. Here, we show that the tRNA CGG Pro m1G37 modification is important for the association step during binding to a cognate CCG codon. In contrast, m1G37 prevented association with a slippery CCC-U or +1 codon. Similar analyses of frameshift suppressor tRNASufA6, a tRNA CGG Pro derivative containing an extra nucleotide in its anticodon loop that undergoes +1 frameshifting, reveal that m1G37 destabilizes interactions with both the cognate CCG and slippery codons. One reason for this destabilization is the disruption of a conserved U32·A38 nucleotide pairing in the anticodon stem through insertion of G37.5. Restoring the tRNASufA6 U32·A37.5 pairing results in a high-affinity association on the slippery CCC-U codon. Further, an X-ray crystal structure of the 70S ribosome bound to tRNASufA6 U32·A37.5 at 3.6 Å resolution shows a reordering of the anticodon loop consistent with the findings from the high-affinity measurements. Our results reveal how the tRNA modification at nucleotide 37 stabilizes interactions with the mRNA codon to preserve the mRNA frame.
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Affiliation(s)
- Ha An Nguyen
- From the Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia 30322 and
- the Department of Chemistry, Emory University, Atlanta, Georgia 30322
| | - Eric D Hoffer
- From the Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia 30322 and
| | - Christine M Dunham
- From the Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia 30322 and
- the Department of Chemistry, Emory University, Atlanta, Georgia 30322
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83
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Ou X, Cao J, Cheng A, Peppelenbosch MP, Pan Q. Errors in translational decoding: tRNA wobbling or misincorporation? PLoS Genet 2019; 15:e1008017. [PMID: 30921315 PMCID: PMC6438450 DOI: 10.1371/journal.pgen.1008017] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
As the central dogma of molecular biology, genetic information flows from DNA through transcription into RNA followed by translation of the message into protein by transfer RNAs (tRNAs). However, mRNA translation is not always perfect, and errors in the amino acid composition may occur. Mistranslation is generally well tolerated, but once it reaches superphysiological levels, it can give rise to a plethora of diseases. The key causes of mistranslation are errors in translational decoding of the codons in mRNA. Such errors mainly derive from tRNA misdecoding and misacylation, especially when certain codon-paired tRNA species are missing. Substantial progress has recently been made with respect to the mechanistic basis of erroneous mRNA decoding as well as the resulting consequences for physiology and pathology. Here, we aim to review this progress with emphasis on viral evolution and cancer development.
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Affiliation(s)
- Xumin Ou
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
- Department of Gastroenterology and Hepatology, Erasmus MC-University Medical Center, Rotterdam, the Netherlands
| | - Jingyu Cao
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Anchun Cheng
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan, China
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
- * E-mail: (AC); (QP)
| | - Maikel P. Peppelenbosch
- Department of Gastroenterology and Hepatology, Erasmus MC-University Medical Center, Rotterdam, the Netherlands
| | - Qiuwei Pan
- Department of Gastroenterology and Hepatology, Erasmus MC-University Medical Center, Rotterdam, the Netherlands
- * E-mail: (AC); (QP)
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84
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Amiri H, Noller HF. Structural evidence for product stabilization by the ribosomal mRNA helicase. RNA (NEW YORK, N.Y.) 2019; 25:364-375. [PMID: 30552154 PMCID: PMC6380275 DOI: 10.1261/rna.068965.118] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Accepted: 12/12/2018] [Indexed: 06/09/2023]
Abstract
Protein synthesis in all organisms proceeds by stepwise translocation of the ribosome along messenger RNAs (mRNAs), during which the helicase activity of the ribosome unwinds encountered structures in the mRNA. This activity is known to occur near the mRNA tunnel entrance, which is lined by ribosomal proteins uS3, uS4, and uS5. However, the mechanism(s) of mRNA unwinding by the ribosome and the possible role of these proteins in the helicase activity are not well understood. Here, we present a crystal structure of the Escherichia coli ribosome in which single-stranded mRNA is observed beyond the tunnel entrance, interacting in an extended conformation with a positively charged patch on ribosomal protein uS3 immediately outside the entrance. This apparent binding specificity for single-stranded mRNA ahead of the tunnel entrance suggests that product stabilization may play a role in the unwinding of structured mRNA by the ribosomal helicase.
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Affiliation(s)
- Hossein Amiri
- Center for Molecular Biology of RNA and Department of Molecular, Cell and Developmental Biology, University of California at Santa Cruz, Santa Cruz, California 95064, USA
| | - Harry F Noller
- Center for Molecular Biology of RNA and Department of Molecular, Cell and Developmental Biology, University of California at Santa Cruz, Santa Cruz, California 95064, USA
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85
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Yang J, Hong J, Luo L, Liu K, Meng C, Ji ZL, Lin D. Biophysical characterization and ligand-binding properties of the elongation factor Tu from Mycobacterium tuberculosis. Acta Biochim Biophys Sin (Shanghai) 2019; 51:139-149. [PMID: 30615070 DOI: 10.1093/abbs/gmy164] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 11/28/2018] [Accepted: 11/30/2018] [Indexed: 02/05/2023] Open
Abstract
Mycobacterium tuberculosis (Mtb) is the key devastating bacterial pathogen responsible for tuberculosis. Increasing emergence of multi-drug-resistant, extensively drug-resistant, and rifampicin/isoniazid-resistant strains of Mtb makes the discovery of validated drug targets an urgent priority. As a vital translational component of the protein biosynthesis system, elongation factor Tu (EF-Tu) is an important molecular switch responsible for selection and binding of the cognate aminoacyl-tRNA to the acceptor site on the ribosome. In addition, EF-Tu from Mtb (MtbEF-Tu) is involved in the initial step of trans-translation which is an effective system for rescuing the stalled ribosomes from non-stop translation complexes under stress conditions. Given its crucial role in protein biosynthesis, EF-Tu is identified as an excellent molecular target for drug design. Here, we reported the recombinant expression, purification, biophysical characterization, and structural modeling of the MtbEF-Tu protein. Our results demonstrated that prokaryotic expression plasmids of pET28a-MtbEF-Tu could be expressed efficiently in Escherichia coli. We successfully purified the 6× His-tagged proteins with a yield of 16.8 mg from 1 l of Luria Bertani medium. Dynamic light scattering experiments showed that MtbEF-Tu existed in a monomeric form, and circular dichroism experiments indicated that MtbEF-Tu was well structured. Moreover, isothermal titration calorimetry experiments displayed that the purified MtbEF-Tu protein possessed intermediate binding affinities for guanosine-5'-triphosphate (GTP) and GDP. The GTP/GDP-binding sites were predicted by flexible molecular docking approach which reveals that GTP/GDP binds to MtbEF-Tu mainly through hydrogen bonds. Our work lays the essential basis for further structural and functional studies of MtbEF-Tu as well as MtbEF-Tu-related novel drug developments.
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Affiliation(s)
- Juanjuan Yang
- Institute of Pharmaceutical Biotechnology and Engineering, College of Biological Science and Biotechnology, Fuzhou University, Fuzhou, China
| | - Jing Hong
- Institute of Pharmaceutical Biotechnology and Engineering, College of Biological Science and Biotechnology, Fuzhou University, Fuzhou, China
| | - Ling Luo
- Institute of Pharmaceutical Biotechnology and Engineering, College of Biological Science and Biotechnology, Fuzhou University, Fuzhou, China
| | - Ke Liu
- State Key Laboratory of Stress Cell Biology, School of Life Sciences, Xiamen University, Xiamen, China
| | - Chun Meng
- Institute of Pharmaceutical Biotechnology and Engineering, College of Biological Science and Biotechnology, Fuzhou University, Fuzhou, China
| | - Zhi-liang Ji
- State Key Laboratory of Stress Cell Biology, School of Life Sciences, Xiamen University, Xiamen, China
| | - Donghai Lin
- High-Field NMR Center, Key Laboratory for Chemical Biology of Fujian Province, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, China
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86
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Ying L, Zhu H, Shoji S, Fredrick K. Roles of specific aminoglycoside-ribosome interactions in the inhibition of translation. RNA (NEW YORK, N.Y.) 2019; 25:247-254. [PMID: 30413565 PMCID: PMC6348987 DOI: 10.1261/rna.068460.118] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 11/06/2018] [Indexed: 05/18/2023]
Abstract
Aminoglycosides containing a 2-deoxystreptamine core (AGs) represent a large family of antibiotics that target the ribosome. These compounds promote miscoding, inhibit translocation, and inhibit ribosome recycling. AG binding to helix h44 of the small subunit induces rearrangement of A-site nucleotides A1492 and A1493, which promotes a key open-to-closed conformational change of the subunit and thereby increases miscoding. Mechanisms by which AGs inhibit translocation and recycling remain less clear. Structural studies have revealed a secondary AG binding site in H69 of the large subunit, and it has been proposed that interaction at this site is crucial for inhibition of translocation and recycling. Here, we analyze ribosomes with mutations targeting either or both AG binding sites. Assaying translocation, we find that ablation of the h44 site increases the IC50 values for AGs dramatically, while removal of the H69 site increases these values modestly. This suggests that the AG-h44 interaction is primarily responsible for inhibition, with H69 playing a minor role. Assaying recycling, we find that mutation of h44 has no effect on AG inhibition, consistent with a primary role for AG-H69 interaction. Collectively, these findings help clarify the roles of the two AG binding sites in mechanisms of inhibition by these compounds.
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Affiliation(s)
- Lanqing Ying
- Department of Microbiology and Center for RNA Biology, The Ohio State University, Columbus, Ohio 43210, USA
| | - Hongkun Zhu
- Department of Microbiology and Center for RNA Biology, The Ohio State University, Columbus, Ohio 43210, USA
| | - Shinichiro Shoji
- Department of Microbiology and Center for RNA Biology, The Ohio State University, Columbus, Ohio 43210, USA
| | - Kurt Fredrick
- Department of Microbiology and Center for RNA Biology, The Ohio State University, Columbus, Ohio 43210, USA
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87
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High-Resolution Ribosome Profiling Defines Discrete Ribosome Elongation States and Translational Regulation during Cellular Stress. Mol Cell 2019; 73:959-970.e5. [PMID: 30686592 DOI: 10.1016/j.molcel.2018.12.009] [Citation(s) in RCA: 153] [Impact Index Per Article: 30.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 10/25/2018] [Accepted: 12/12/2018] [Indexed: 12/19/2022]
Abstract
Ribosomes undergo substantial conformational changes during translation elongation to accommodate incoming aminoacyl-tRNAs and translocate along the mRNA template. We used multiple elongation inhibitors and chemical probing to define ribosome conformational states corresponding to differently sized ribosome-protected mRNA fragments (RPFs) generated by ribosome profiling. We show, using various genetic and environmental perturbations, that short 20-22 or classical 27-29 nucleotide RPFs correspond to ribosomes with open or occupied ribosomal A sites, respectively. These distinct states of translation elongation are readily discerned by ribosome profiling in all eukaryotes we tested, including fungi, worms, and mammals. This high-resolution ribosome profiling approach reveals mechanisms of translation-elongation arrest during distinct stress conditions. Hyperosmotic stress inhibits translocation through Rck2-dependent eEF2 phosphorylation, whereas oxidative stress traps ribosomes in a pre-translocation state, independent of Rck2-driven eEF2 phosphorylation. These results provide insights and approaches for defining the molecular events that impact translation elongation throughout biology.
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88
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Joshi K, Cao L, Farabaugh PJ. The problem of genetic code misreading during protein synthesis. Yeast 2019; 36:35-42. [DOI: 10.1002/yea.3374] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Revised: 12/11/2018] [Accepted: 12/13/2018] [Indexed: 02/01/2023] Open
Affiliation(s)
- Kartikeya Joshi
- Department of Biological Sciences; University of Maryland Baltimore County; Baltimore Maryland, USA
| | - Ling Cao
- Department of Biological Sciences; University of Maryland Baltimore County; Baltimore Maryland, USA
| | - Philip J. Farabaugh
- Department of Biological Sciences; University of Maryland Baltimore County; Baltimore Maryland, USA
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89
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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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90
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Flis J, Holm M, Rundlet EJ, Loerke J, Hilal T, Dabrowski M, Bürger J, Mielke T, Blanchard SC, Spahn CMT, Budkevich TV. tRNA Translocation by the Eukaryotic 80S Ribosome and the Impact of GTP Hydrolysis. Cell Rep 2018; 25:2676-2688.e7. [PMID: 30517857 PMCID: PMC6314685 DOI: 10.1016/j.celrep.2018.11.040] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 09/14/2018] [Accepted: 11/09/2018] [Indexed: 01/04/2023] Open
Abstract
Translocation moves the tRNA2⋅mRNA module directionally through the ribosome during the elongation phase of protein synthesis. Although translocation is known to entail large conformational changes within both the ribosome and tRNA substrates, the orchestrated events that ensure the speed and fidelity of this critical aspect of the protein synthesis mechanism have not been fully elucidated. Here, we present three high-resolution structures of intermediates of translocation on the mammalian ribosome where, in contrast to bacteria, ribosomal complexes containing the translocase eEF2 and the complete tRNA2⋅mRNA module are trapped by the non-hydrolyzable GTP analog GMPPNP. Consistent with the observed structures, single-molecule imaging revealed that GTP hydrolysis principally facilitates rate-limiting, final steps of translocation, which are required for factor dissociation and which are differentially regulated in bacterial and mammalian systems by the rates of deacyl-tRNA dissociation from the E site.
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Affiliation(s)
- Julia Flis
- Institut für Medizinische Physik und Biophysik, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
| | - Mikael Holm
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY, USA
| | - Emily J Rundlet
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY, USA; Tri-Institutional PhD Program in Chemical Biology, Weill Cornell Medicine, New York, NY, USA
| | - Justus Loerke
- Institut für Medizinische Physik und Biophysik, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
| | - Tarek Hilal
- Institut für Medizinische Physik und Biophysik, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
| | - Marylena Dabrowski
- Institut für Medizinische Physik und Biophysik, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
| | - Jörg Bürger
- Institut für Medizinische Physik und Biophysik, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany; UltraStrukturNetzwerk, Max Planck Institute for Molecular Genetics, 14195 Berlin, Germany
| | - Thorsten Mielke
- UltraStrukturNetzwerk, Max Planck Institute for Molecular Genetics, 14195 Berlin, Germany
| | - Scott C Blanchard
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY, USA; Tri-Institutional PhD Program in Chemical Biology, Weill Cornell Medicine, New York, NY, USA.
| | - Christian M T Spahn
- Institut für Medizinische Physik und Biophysik, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany.
| | - Tatyana V Budkevich
- Institut für Medizinische Physik und Biophysik, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany.
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91
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Joshi K, Bhatt MJ, Farabaugh PJ. Codon-specific effects of tRNA anticodon loop modifications on translational misreading errors in the yeast Saccharomyces cerevisiae. Nucleic Acids Res 2018; 46:10331-10339. [PMID: 30060218 PMCID: PMC6212777 DOI: 10.1093/nar/gky664] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Revised: 07/03/2018] [Accepted: 07/12/2018] [Indexed: 01/10/2023] Open
Abstract
Protein synthesis requires both high speed and accuracy to ensure a healthy cellular environment. Estimates of errors during protein synthesis in Saccharomyces cerevisiae have varied from 10-3 to 10-4 errors per codon. Here, we show that errors made by ${\rm{tRNA}}^{\rm Glu}_{\rm UUC}$ in yeast can vary 100-fold, from 10-6 to 10-4 errors per codon. The most frequent errors require a G•U mismatch at the second position for the near cognate codon GGA (Gly). We also show, contrary to our previous results, that yeast tRNAs can make errors involving mismatches at the wobble position but with low efficiency. We have also assessed the effect on misreading frequency of post-transcriptional modifications of tRNAs, which are known to regulate cognate codon decoding in yeast. We tested the roles of mcm5s2U34 and t6A37 and show that their effects depend on details of the codon anticodon interaction including the position of the modification with respect to the base mismatch and the nature of that mismatch. Both mcm5 and s2 modification of wobble uridine strongly stabilizes G2•U35 mismatches when ${\rm{tRNA}}^{\rm Glu}_{\rm UUC}$ misreads the GGA Gly codon but has weaker effects on other mismatches. By contrast, t6A37 destabilizes U1•U36 mismatches when ${\rm{tRNA}}^{\rm Lys}_{\rm UUU}$ misreads UAA or UAG but stabilizes mismatches at the second and wobble positions.
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Affiliation(s)
- Kartikeya Joshi
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, MD 21250, USA
| | - Monika J Bhatt
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, MD 21250, USA
| | - Philip J Farabaugh
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, MD 21250, USA
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92
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Abstract
Accurate translation of the genetic code is critical to ensure expression of proteins with correct amino acid sequences. Certain tRNAs can cause a shift out of frame (i.e., frameshifting) due to imbalances in tRNA concentrations, lack of tRNA modifications or insertions or deletions in tRNAs (called frameshift suppressors). Here, we determined the structural basis for how frameshift-suppressor tRNASufA6 (a derivative of tRNAPro) reprograms the mRNA frame to translate a 4-nt codon when bound to the bacterial ribosome. After decoding at the aminoacyl (A) site, the crystal structure of the anticodon stem-loop of tRNASufA6 bound in the peptidyl (P) site reveals ASL conformational changes that allow for recoding into the +1 mRNA frame. Furthermore, a crystal structure of full-length tRNASufA6 programmed in the P site shows extensive conformational rearrangements of the 30S head and body domains similar to what is observed in a translocation intermediate state containing elongation factor G (EF-G). The 30S movement positions tRNASufA6 toward the 30S exit (E) site disrupting key 16S rRNA-mRNA interactions that typically define the mRNA frame. In summary, this tRNA-induced 30S domain change in the absence of EF-G causes the ribosome to lose its grip on the mRNA and uncouples the canonical forward movement of the tRNAs during elongation.
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93
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Abstract
This review summarizes our current understanding of translation in prokaryotes, focusing on the mechanistic and structural aspects of each phase of translation: initiation, elongation, termination, and ribosome recycling. The assembly of the initiation complex provides multiple checkpoints for messenger RNA (mRNA) and start-site selection. Correct codon-anticodon interaction during the decoding phase of elongation results in major conformational changes of the small ribosomal subunit and shapes the reaction pathway of guanosine triphosphate (GTP) hydrolysis. The ribosome orchestrates proton transfer during peptide bond formation, but requires the help of elongation factor P (EF-P) when two or more consecutive Pro residues are to be incorporated. Understanding the choreography of transfer RNA (tRNA) and mRNA movements during translocation helps to place the available structures of translocation intermediates onto the time axis of the reaction pathway. The nascent protein begins to fold cotranslationally, in the constrained space of the polypeptide exit tunnel of the ribosome. When a stop codon is reached at the end of the coding sequence, the ribosome, assisted by termination factors, hydrolyzes the ester bond of the peptidyl-tRNA, thereby releasing the nascent protein. Following termination, the ribosome is dissociated into subunits and recycled into another round of initiation. At each step of translation, the ribosome undergoes dynamic fluctuations between different conformation states. The aim of this article is to show the link between ribosome structure, dynamics, and function.
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Affiliation(s)
- Marina V Rodnina
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Goettingen 37077, Germany
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94
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Decoding on the ribosome depends on the structure of the mRNA phosphodiester backbone. Proc Natl Acad Sci U S A 2018; 115:E6731-E6740. [PMID: 29967153 DOI: 10.1073/pnas.1721431115] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
During translation, the ribosome plays an active role in ensuring that mRNA is decoded accurately and rapidly. Recently, biochemical studies have also implicated certain accessory factors in maintaining decoding accuracy. However, it is currently unclear whether the mRNA itself plays an active role in the process beyond its ability to base pair with the tRNA. Structural studies revealed that the mRNA kinks at the interface of the P and A sites. A magnesium ion appears to stabilize this structure through electrostatic interactions with the phosphodiester backbone of the mRNA. Here we examined the role of the kink structure on decoding using a well-defined in vitro translation system. Disruption of the kink structure through site-specific phosphorothioate modification resulted in an acute hyperaccurate phenotype. We measured rates of peptidyl transfer for near-cognate tRNAs that were severely diminished and in some instances were almost 100-fold slower than unmodified mRNAs. In contrast to peptidyl transfer, the modifications had little effect on GTP hydrolysis by elongation factor thermal unstable (EF-Tu), suggesting that only the proofreading phase of tRNA selection depends critically on the kink structure. Although the modifications appear to have no effect on typical cognate interactions, peptidyl transfer for a tRNA that uses atypical base pairing is compromised. These observations suggest that the kink structure is important for decoding in the absence of Watson-Crick or G-U wobble base pairing at the third position. Our findings provide evidence for a previously unappreciated role for the mRNA backbone in ensuring uniform decoding of the genetic code.
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95
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Suhm T, Kaimal JM, Dawitz H, Peselj C, Masser AE, Hanzén S, Ambrožič M, Smialowska A, Björck ML, Brzezinski P, Nyström T, Büttner S, Andréasson C, Ott M. Mitochondrial Translation Efficiency Controls Cytoplasmic Protein Homeostasis. Cell Metab 2018; 27:1309-1322.e6. [PMID: 29754951 DOI: 10.1016/j.cmet.2018.04.011] [Citation(s) in RCA: 79] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Revised: 02/02/2018] [Accepted: 04/12/2018] [Indexed: 01/02/2023]
Abstract
Cellular proteostasis is maintained via the coordinated synthesis, maintenance, and breakdown of proteins in the cytosol and organelles. While biogenesis of the mitochondrial membrane complexes that execute oxidative phosphorylation depends on cytoplasmic translation, it is unknown how translation within mitochondria impacts cytoplasmic proteostasis and nuclear gene expression. Here we have analyzed the effects of mutations in the highly conserved accuracy center of the yeast mitoribosome. Decreased accuracy of mitochondrial translation shortened chronological lifespan, impaired management of cytosolic protein aggregates, and elicited a general transcriptional stress response. In striking contrast, increased accuracy extended lifespan, improved cytosolic aggregate clearance, and suppressed a normally stress-induced, Msn2/4-dependent interorganellar proteostasis transcription program (IPTP) that regulates genes important for mitochondrial proteostasis. Collectively, the data demonstrate that cytosolic protein homeostasis and nuclear stress signaling are controlled by mitochondrial translation efficiency in an inter-connected organelle quality control network that determines cellular lifespan.
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Affiliation(s)
- Tamara Suhm
- Department of Biochemistry and Biophysics, Stockholm University, SE-10691 Stockholm, Sweden
| | | | - Hannah Dawitz
- Department of Biochemistry and Biophysics, Stockholm University, SE-10691 Stockholm, Sweden
| | - Carlotta Peselj
- Department of Molecular Biosciences, Wenner-Gren Institute, Stockholm University, SE-10691 Stockholm, Sweden
| | - Anna E Masser
- Department of Molecular Biosciences, Wenner-Gren Institute, Stockholm University, SE-10691 Stockholm, Sweden
| | - Sarah Hanzén
- Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, SE-413 90 Göteborg, Sweden
| | - Matevž Ambrožič
- Department of Biochemistry and Biophysics, Stockholm University, SE-10691 Stockholm, Sweden
| | - Agata Smialowska
- Department of Biochemistry and Biophysics, Stockholm University, SE-10691 Stockholm, Sweden; National Bioinformatics Infrastructure Sweden (NBIS), Science for Life Laboratory, SE-17165 Solna, Sweden
| | - Markus L Björck
- Department of Biochemistry and Biophysics, Stockholm University, SE-10691 Stockholm, Sweden
| | - Peter Brzezinski
- Department of Biochemistry and Biophysics, Stockholm University, SE-10691 Stockholm, Sweden
| | - Thomas Nyström
- Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, SE-413 90 Göteborg, Sweden
| | - Sabrina Büttner
- Department of Molecular Biosciences, Wenner-Gren Institute, Stockholm University, SE-10691 Stockholm, Sweden; Institute of Molecular Biosciences, NAWI Graz, University of Graz, A-8010 Graz, Austria
| | - Claes Andréasson
- Department of Molecular Biosciences, Wenner-Gren Institute, Stockholm University, SE-10691 Stockholm, Sweden.
| | - Martin Ott
- Department of Biochemistry and Biophysics, Stockholm University, SE-10691 Stockholm, Sweden.
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96
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C.P. A, Subhramanian S, Sizochenko N, Melge AR, Leszczynski J, Mohan CG. Multiple e-Pharmacophore modeling to identify a single molecule that could target both streptomycin and paromomycin binding sites for 30S ribosomal subunit inhibition. J Biomol Struct Dyn 2018; 37:1582-1596. [DOI: 10.1080/07391102.2018.1462731] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Anju C.P.
- Centre for Nanosciences and Molecular Medicine, Amrita Institute of Medical Sciences and Research Centre, Amrita Vishwa Vidyapeetham, Kochi 682 041, Kerala, India
| | - Sunitha Subhramanian
- Centre for Nanosciences and Molecular Medicine, Amrita Institute of Medical Sciences and Research Centre, Amrita Vishwa Vidyapeetham, Kochi 682 041, Kerala, India
| | - Natalia Sizochenko
- Interdisciplinary Centre for Nanotoxicity, Department of Chemistry and Biochemistry, Jackson State University, Jackson, MS-39217, MI, USA
| | - Anu R. Melge
- Centre for Nanosciences and Molecular Medicine, Amrita Institute of Medical Sciences and Research Centre, Amrita Vishwa Vidyapeetham, Kochi 682 041, Kerala, India
| | - Jerzy Leszczynski
- Interdisciplinary Centre for Nanotoxicity, Department of Chemistry and Biochemistry, Jackson State University, Jackson, MS-39217, MI, USA
| | - C. Gopi Mohan
- Centre for Nanosciences and Molecular Medicine, Amrita Institute of Medical Sciences and Research Centre, Amrita Vishwa Vidyapeetham, Kochi 682 041, Kerala, India
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97
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Amini SK. Relative Populations of Some Tautomeric Forms of 2'-Deoxyguanosine-5-Fluorouridine Mismatch. J Phys Chem B 2018; 122:4433-4444. [PMID: 29608855 DOI: 10.1021/acs.jpcb.8b00818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The importance of the 2'-deoxyguanosine-uridine mispair as the most occurring mismatch in transcriptional studies of RNAs from DNAs is multiplied when 5-halo-substituted uridine species cause a serious increase in the probability of its occurrence. Many studies relate this higher probability to the existence of possible tautomeric and ionic forms of its constituent bases. According to these statements, relative populations of mismatches between 5-fluorouridine and both keto and enol forms of 2'-deoxyguanosine are computed by using a conformational search. In order to have a complete scan of all of the highly probable conformers in a moderate computational time, an extensive conformational search methodology is employed here, which benefits from the advantages of both the molecular dynamics simulations and quantum mechanics calculations. The population of an enolic tautomer of normal wobble orientation is about 0.057% of that of its keto tautomer, whereas the population of an enolic tautomer of reverse wobble orientation is about 0.0054% of that of its keto tautomer. Totally, the reverse wobble orientation is about six times more populated than the normal wobble orientation. Calculated populations are in good agreement with experimental populations of closely related compounds. The reliability of the applied methodology is certified, in part, by a good agreement obtained between some experimental data and corresponding Boltzmann-weighted average data of most probable conformers such as NMR parameters. The validation of this methodology is certified with high accuracy by applying it on the substituted diuridine pairs, where experimental populations are available. Not only are the calculated populations and NMR parameters of this test in very good agreement with the experimental data, but also they are free of the ambiguities mentioned by experimentalists.
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Affiliation(s)
- Saeed K Amini
- Chemistry and Chemical Engineering Research Center of Iran , Tehran , Iran
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98
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Šponer J, Bussi G, Krepl M, Banáš P, Bottaro S, Cunha RA, Gil-Ley A, Pinamonti G, Poblete S, Jurečka P, Walter NG, Otyepka M. RNA Structural Dynamics As Captured by Molecular Simulations: A Comprehensive Overview. Chem Rev 2018; 118:4177-4338. [PMID: 29297679 PMCID: PMC5920944 DOI: 10.1021/acs.chemrev.7b00427] [Citation(s) in RCA: 327] [Impact Index Per Article: 54.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Indexed: 12/14/2022]
Abstract
With both catalytic and genetic functions, ribonucleic acid (RNA) is perhaps the most pluripotent chemical species in molecular biology, and its functions are intimately linked to its structure and dynamics. Computer simulations, and in particular atomistic molecular dynamics (MD), allow structural dynamics of biomolecular systems to be investigated with unprecedented temporal and spatial resolution. We here provide a comprehensive overview of the fast-developing field of MD simulations of RNA molecules. We begin with an in-depth, evaluatory coverage of the most fundamental methodological challenges that set the basis for the future development of the field, in particular, the current developments and inherent physical limitations of the atomistic force fields and the recent advances in a broad spectrum of enhanced sampling methods. We also survey the closely related field of coarse-grained modeling of RNA systems. After dealing with the methodological aspects, we provide an exhaustive overview of the available RNA simulation literature, ranging from studies of the smallest RNA oligonucleotides to investigations of the entire ribosome. Our review encompasses tetranucleotides, tetraloops, a number of small RNA motifs, A-helix RNA, kissing-loop complexes, the TAR RNA element, the decoding center and other important regions of the ribosome, as well as assorted others systems. Extended sections are devoted to RNA-ion interactions, ribozymes, riboswitches, and protein/RNA complexes. Our overview is written for as broad of an audience as possible, aiming to provide a much-needed interdisciplinary bridge between computation and experiment, together with a perspective on the future of the field.
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Affiliation(s)
- Jiří Šponer
- Institute of Biophysics of the Czech Academy of Sciences , Kralovopolska 135 , Brno 612 65 , Czech Republic
| | - Giovanni Bussi
- Scuola Internazionale Superiore di Studi Avanzati , Via Bonomea 265 , Trieste 34136 , Italy
| | - Miroslav Krepl
- Institute of Biophysics of the Czech Academy of Sciences , Kralovopolska 135 , Brno 612 65 , Czech Republic
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science , Palacky University Olomouc , 17. listopadu 12 , Olomouc 771 46 , Czech Republic
| | - Pavel Banáš
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science , Palacky University Olomouc , 17. listopadu 12 , Olomouc 771 46 , Czech Republic
| | - Sandro Bottaro
- Structural Biology and NMR Laboratory, Department of Biology , University of Copenhagen , Copenhagen 2200 , Denmark
| | - Richard A Cunha
- Scuola Internazionale Superiore di Studi Avanzati , Via Bonomea 265 , Trieste 34136 , Italy
| | - Alejandro Gil-Ley
- Scuola Internazionale Superiore di Studi Avanzati , Via Bonomea 265 , Trieste 34136 , Italy
| | - Giovanni Pinamonti
- Scuola Internazionale Superiore di Studi Avanzati , Via Bonomea 265 , Trieste 34136 , Italy
| | - Simón Poblete
- Scuola Internazionale Superiore di Studi Avanzati , Via Bonomea 265 , Trieste 34136 , Italy
| | - Petr Jurečka
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science , Palacky University Olomouc , 17. listopadu 12 , Olomouc 771 46 , Czech Republic
| | - Nils G Walter
- Single Molecule Analysis Group and Center for RNA Biomedicine, Department of Chemistry , University of Michigan , Ann Arbor , Michigan 48109 , United States
| | - Michal Otyepka
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science , Palacky University Olomouc , 17. listopadu 12 , Olomouc 771 46 , Czech Republic
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99
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Devi M, Chingbiaknem E, Lyngdoh RHD. A molecular mechanics study on GA codon box translation. J Theor Biol 2018; 441:28-43. [PMID: 29305181 DOI: 10.1016/j.jtbi.2018.01.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Revised: 01/01/2018] [Accepted: 01/02/2018] [Indexed: 11/28/2022]
Abstract
The GA codon box incorporates the two-fold degeneracy of aspartic acid and of glutamic acid. Using the molecular mechanics approach of the AMBER suite, the four codons of the GA box are paired via H-bonding with two aspartic acid anticodons and two glutamic acid anticodons to yield 8 cognate and 11 non-cognate codon-anticodon duplexes. In addition four select non-cognate duplexes between the GA box codons and three alanine anticodons are also studied. These 23 duplexes display a variety of base-pairing possibilities at the wobble position. Cognate duplexes are differentiated from non-cognate duplexes on the grounds of structure and stability (chiefly the former). The results are in line with Crick's wobble hypothesis, and corroborate the observed reading properties of the aspartic acid anticodons GUC and QUC and of the glutamic acid anticodons CUC and SmnUC.
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Affiliation(s)
- Martina Devi
- Department of Chemistry, North-Eastern Hill University, Shillong 793022, India
| | - Esther Chingbiaknem
- Department of Chemistry, North-Eastern Hill University, Shillong 793022, India
| | - R H Duncan Lyngdoh
- Department of Chemistry, North-Eastern Hill University, Shillong 793022, India.
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100
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Fu X, Söll D, Sevostyanova A. Challenges of site-specific selenocysteine incorporation into proteins by Escherichia coli. RNA Biol 2018; 15:461-470. [PMID: 29447106 DOI: 10.1080/15476286.2018.1440876] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Selenocysteine (Sec), a rare genetically encoded amino acid with unusual chemical properties, is of great interest for protein engineering. Sec is synthesized on its cognate tRNA (tRNASec) by the concerted action of several enzymes. While all other aminoacyl-tRNAs are delivered to the ribosome by the elongation factor Tu (EF-Tu), Sec-tRNASec requires a dedicated factor, SelB. Incorporation of Sec into protein requires recoding of the stop codon UGA aided by a specific mRNA structure, the SECIS element. This unusual biogenesis restricts the use of Sec in recombinant proteins, limiting our ability to study the properties of selenoproteins. Several methods are currently available for the synthesis selenoproteins. Here we focus on strategies for in vivo Sec insertion at any position(s) within a recombinant protein in a SECIS-independent manner: (i) engineering of tRNASec for use by EF-Tu without the SECIS requirement, and (ii) design of a SECIS-independent SelB route.
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Affiliation(s)
- Xian Fu
- a Department of Molecular Biophysics and Biochemistry , Yale University , New Haven , CT , USA
| | - Dieter Söll
- a Department of Molecular Biophysics and Biochemistry , Yale University , New Haven , CT , USA.,b Department of Chemistry , Yale University , New Haven , CT , USA
| | - Anastasia Sevostyanova
- a Department of Molecular Biophysics and Biochemistry , Yale University , New Haven , CT , USA
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