151
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Agmon IC. A model for the role of isomerization in nascent peptide movement through the ribosomal tunnel. FASEB J 2012; 26:2277-82. [DOI: 10.1096/fj.11-197657] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Ilana C. Agmon
- Institute for Advanced Studies in Theoretical ChemistrySchulich Faculty of Chemistry, TechnionIsrael Institute of TechnologyHaifaIsrael
- Fritz Haber Research Center for Molecular DynamicsHebrew UniversityJerusalemIsrael
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152
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Vivanco-Domínguez S, Bueno-Martínez J, León-Avila G, Iwakura N, Kaji A, Kaji H, Guarneros G. Protein synthesis factors (RF1, RF2, RF3, RRF, and tmRNA) and peptidyl-tRNA hydrolase rescue stalled ribosomes at sense codons. J Mol Biol 2012; 417:425-39. [PMID: 22326347 DOI: 10.1016/j.jmb.2012.02.008] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2011] [Revised: 01/17/2012] [Accepted: 02/03/2012] [Indexed: 10/14/2022]
Abstract
During translation, ribosomes stall on mRNA when the aminoacyl-tRNA to be read is not readily available. The stalled ribosomes are deleterious to the cell and should be rescued to maintain its viability. To investigate the contribution of some of the cellular translation factors on ribosome rescuing, we provoked stalling at AGA codons in mutants that affected the factors and then analyzed the accumulation of oligopeptidyl (peptides of up to 6 amino acid residues, oligopep-)-tRNA or polypeptidyl (peptides of more than 300 amino acids in length, polypep-)-tRNA associated with ribosomes. Stalling was achieved by starvation for aminoacyl-tRNA(Arg4) upon induced expression of engineered lacZ (β-galactosidase) reporter gene harboring contiguous AGA codons close to the initiation codon or at internal codon positions together with minigene ATGAGATAA accompanied by reduced peptidyl-tRNA hydrolase (Pth). Our results showed accumulations of peptidyl-tRNA associated with ribosomes in mutants for release factors (RF1, RF2, and RF3), ribosome recycling factor (RRF), Pth, and transfer-messenger RNA (tmRNA), implying that each of these factors cooperate in rescuing stalled ribosomes. The role of these factors in ribosome releasing from the stalled complex may vary depending on the length of the peptide in the peptidyl-tRNA. RF3 and RRF rescue stalled ribosomes by "drop-off" of peptidyl-tRNA, while RF1, RF2 (in the absence of termination codon), or Pth may rescue by hydrolyzing the associated peptidyl-tRNA. This is followed by the disassembly of the ribosomal complex of tRNA and mRNA by RRF and elongation factor G.
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Affiliation(s)
- Serafín Vivanco-Domínguez
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, P.O. Box 14-740, Mexico City, 07000, Mexico
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153
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Ito K, Chadani Y, Nakamori K, Chiba S, Akiyama Y, Abo T. Nascentome analysis uncovers futile protein synthesis in Escherichia coli. PLoS One 2011; 6:e28413. [PMID: 22162769 PMCID: PMC3230602 DOI: 10.1371/journal.pone.0028413] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2011] [Accepted: 11/07/2011] [Indexed: 11/19/2022] Open
Abstract
Although co-translational biological processes attract much attention, no general and easy method has been available to detect cellular nascent polypeptide chains, which we propose to call collectively a “nascentome.” We developed a method to selectively detect polypeptide portions of cellular polypeptidyl-tRNAs and used it to study the generality of the quality control reactions that rescue dead-end translation complexes. To detect nascent polypeptides, having their growing ends covalently attached to a tRNA, cellular extracts are separated by SDS-PAGE in two dimensions, first with the peptidyl-tRNA ester bonds preserved and subsequently after their in-gel cleavage. Pulse-labeled nascent polypeptides of Escherichia coli form a characteristic line below the main diagonal line, because each of them had contained a tRNA of nearly uniform size in the first-dimension electrophoresis but not in the second-dimension. The detection of nascent polypeptides, separately from any translation-completed polypeptides or degradation products thereof, allows us to follow their fates to gain deeper insights into protein biogenesis and quality control pathways. It was revealed that polypeptidyl-tRNAs were significantly stabilized in E. coli upon dysfunction of the tmRNA-ArfA ribosome-rescuing system, whose function had only been studied previously using model constructs. Our results suggest that E. coli cells are intrinsically producing aberrant translation products, which are normally eliminated by the ribosome-rescuing mechanisms.
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Affiliation(s)
- Koreaki Ito
- Faculty of Life Sciences, Kyoto Sangyo University, Kyoto, Japan.
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154
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Sharma P, Yan F, Doronina VA, Escuin-Ordinas H, Ryan MD, Brown JD. 2A peptides provide distinct solutions to driving stop-carry on translational recoding. Nucleic Acids Res 2011; 40:3143-51. [PMID: 22140113 PMCID: PMC3326317 DOI: 10.1093/nar/gkr1176] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Expression of viral proteins frequently includes non-canonical decoding events (‘recoding’) during translation. ‘2A’ oligopeptides drive one such event, termed ‘stop-carry on’ recoding. Nascent 2A peptides interact with the ribosomal exit tunnel to dictate an unusual stop codon-independent termination of translation at the final Pro codon of 2A. Subsequently, translation ‘reinitiates’ on the same codon, two individual proteins being generated from one open reading frame. Many 2A peptides have been identified, and they have a conserved C-terminal motif. Little similarity is present in the N-terminal portions of these peptides, which might suggest that these amino acids are not important in the 2A reaction. However, mutagenesis indicates that identity of the amino acid at nearly all positions of a single 2A peptide is important for activity. Each 2A may then represent a specific solution for positioning the conserved C-terminus within the peptidyl-transferase centre to promote recoding. Nascent 2A peptide:ribosome interactions are suggested to alter ribosomal fine structure to discriminate against prolyl-tRNAPro and promote termination in the absence of a stop codon. Such structural modifications may account for our observation that replacement of the final Pro codon of 2A with any stop codon both stalls ribosome processivity and inhibits nascent chain release.
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Affiliation(s)
- Pamila Sharma
- RNA Biology Group and Institute for Cell and Molecular Biosciences, The Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
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155
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Martínez AK, Shirole NH, Murakami S, Benedik MJ, Sachs MS, Cruz-Vera LR. Crucial elements that maintain the interactions between the regulatory TnaC peptide and the ribosome exit tunnel responsible for Trp inhibition of ribosome function. Nucleic Acids Res 2011; 40:2247-57. [PMID: 22110039 PMCID: PMC3299997 DOI: 10.1093/nar/gkr1052] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Translation of the TnaC nascent peptide inhibits ribosomal activity in the presence of l-tryptophan, inducing expression of the tnaCAB operon in Escherichia coli. Using chemical methylation, this work reveals how interactions between TnaC and the ribosome are affected by mutations in both molecules. The presence of the TnaC-tRNAPro peptidyl-tRNA within the ribosome protects the 23S rRNA nucleotide U2609 against chemical methylation. Such protection was not observed in mutant ribosomes containing changes in 23S rRNA nucleotides of the A748–A752 region. Nucleotides A752 and U2609 establish a base-pair interaction. Most replacements of either A752 or U2609 affected Trp induction of a TnaC-regulated LacZ reporter. However, the single change A752G, or the dual replacements A752G and U2609C, maintained Trp induction. Replacements at the conserved TnaC residues W12 and D16 also abolished the protection of U2609 by TnaC-tRNAPro against chemical methylation. These data indicate that the TnaC nascent peptide in the ribosome exit tunnel interacts with the U2609 nucleotide when the ribosome is Trp responsive. This interaction is affected by mutational changes in exit tunnel nucleotides of 23S rRNA, as well as in conserved TnaC residues, suggesting that they affect the structure of the exit tunnel and/or the nascent peptide configuration in the tunnel.
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Affiliation(s)
- Allyson K Martínez
- Department of Biology, Texas A&M University, College Station, TX 77843, USA
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156
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The ribosomal tunnel as a functional environment for nascent polypeptide folding and translational stalling. Curr Opin Struct Biol 2011; 21:274-82. [PMID: 21316217 DOI: 10.1016/j.sbi.2011.01.007] [Citation(s) in RCA: 141] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2010] [Revised: 12/16/2010] [Accepted: 01/19/2011] [Indexed: 12/14/2022]
Abstract
As the nascent polypeptide chain is being synthesized, it passes through a tunnel within the large ribosomal subunit and emerges at the solvent side where protein folding occurs. Despite the universality and conservation of dimensions of the ribosomal tunnel, a functional role for the ribosomal tunnel is only beginning to emerge: Rather than a passive conduit for the nascent chain, accumulating evidence indicates that the tunnel plays a more active role. In this article, we discuss recent structural insights into the role of the tunnel environment, and its implications for protein folding, co-translational targeting and translation regulation.
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157
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Role of antibiotic ligand in nascent peptide-dependent ribosome stalling. Proc Natl Acad Sci U S A 2011; 108:10496-501. [PMID: 21670252 DOI: 10.1073/pnas.1103474108] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Specific nascent peptides in the ribosome exit tunnel can elicit translation arrest. Such ribosome stalling is used for regulation of expression of some bacterial and eukaryotic genes. The stalling is sensitive to additional cellular cues, most commonly the binding of specific small-molecular-weight cofactors to the ribosome. The role of cofactors in programmed translation arrest is unknown. By analyzing nascent peptide- and antibiotic-dependent ribosome stalling that controls inducible expression of antibiotic resistance genes in bacteria, we have found that the antibiotic is directly recognized as a part of the translation modulating signal. Even minute structural alterations preclude it from assisting in ribosome stalling, indicating the importance of precise molecular interactions of the drug with the ribosome. One of the sensors that monitor the structure of the antibiotic is the 23S rRNA residue C2610, whose mutation reduces the efficiency of nascent peptide- and antibiotic-dependent ribosome stalling. These findings establish a new paradigm of the role of the cofactor in programmed translation arrest in which a small molecule is recognized along with specific nascent peptide sequences as a composite structure that provokes arrest of translation. A similar mechanism could be used by the ribosome to sense a variety of cellular metabolites.
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158
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Abstract
Metal ions are the salt in the soup of essentially every biological system. Also in the ribosome, the largest natural ribozyme that produces all proteins in every living cell, metal ions have been found contributing significantly to the highly dynamic and accurate process of translation. The ribosome is considered a molecular fossil of the 'RNA world' and it could be shown that the evolutionarily oldest parts of the particle, which build the catalytic center and surrounding domains, are densely packed with divalent metal ions. Nevertheless, metal ions do not seem to directly participate in ribosomal catalysis, their important roles in the ribosome, however, cannot be denied. It is probable that mono- and divalent metal ions primarily promote the functionally competent architecture of the ribosomal RNAs, but more direct roles in mRNA decoding and reading frame maintenance are likely. Decades of biochemical studies and the recent high resolution crystallographic structures of the ribosome strongly indicate that metal ions are involved in essentially every phase of the ribosomal elongation cycle, thus contributing significantly to the precise translation of the genetic code.
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Affiliation(s)
- Krista Trappl
- Innsbruck Biocenter, Division of Genomics and RNomics, Medical University Innsbruck, Fritz-Pregl-Strasse 3, 6020 Innsbruck, Austria.
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159
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Ramu H, Vázquez-Laslop N, Klepacki D, Dai Q, Piccirilli J, Micura R, Mankin AS. Nascent peptide in the ribosome exit tunnel affects functional properties of the A-site of the peptidyl transferase center. Mol Cell 2011; 41:321-30. [PMID: 21292164 DOI: 10.1016/j.molcel.2010.12.031] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2010] [Revised: 10/30/2010] [Accepted: 11/11/2010] [Indexed: 11/28/2022]
Abstract
The ability to monitor the nascent peptide structure and to respond functionally to specific nascent peptide sequences is a fundamental property of the ribosome. An extreme manifestation of such response is nascent peptide-dependent ribosome stalling, involved in the regulation of gene expression. The molecular mechanisms of programmed translation arrest are unclear. By analyzing ribosome stalling at the regulatory cistron of the antibiotic resistance gene ermA, we uncovered a carefully orchestrated cooperation between the ribosomal exit tunnel and the A-site of the peptidyl transferase center (PTC) in halting translation. The presence of an inducing antibiotic and a specific nascent peptide in the exit tunnel abrogate the ability of the PTC to catalyze peptide bond formation with a particular subset of amino acids. The extent of the conferred A-site selectivity is modulated by the C-terminal segment of the nascent peptide, where the third-from-last residue plays a critical role.
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Affiliation(s)
- Haripriya Ramu
- Center for Pharmaceutical Biotechnology, University of Illinois, Chicago, IL 60607, USA
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160
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161
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Abstract
In this issue of Molecular Cell, Ramu et al. demonstrate that nascent peptides located within the ribosomal tunnel can talk back to the peptidyl transferase center to induce translational stalling by restricting the species of aminoacyl-tRNAs that can bind there.
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Affiliation(s)
- Daniel N Wilson
- Gene Center and Department for Biochemistry, Center for Protein Science-Munich (CiPS-M), University of Munich, Feodor-Lynen-Strasse 25, D-81377 Munich, Germany.
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162
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Nascent polypeptide sequences that influence ribosome function. Curr Opin Microbiol 2011; 14:160-6. [PMID: 21342782 DOI: 10.1016/j.mib.2011.01.011] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2010] [Accepted: 01/28/2011] [Indexed: 11/23/2022]
Abstract
Ribosomes catalyze protein synthesis using transfer RNAs and auxiliary proteins. Historically, ribosomes have been considered nonspecific translational machines, having no regulatory functions. However, a new class of regulatory mechanisms has been discovered that is based on interactions occurring within the ribosomal peptide exit tunnel that result in ribosome stalling during translation of an appropriate mRNA segment. These discoveries reveal an unexpectedly dynamic role ribosomes play in regulating their own activity. By using nascent leader peptides in combination with bound specific amino acids or antibiotics, ribosome functions can be altered significantly resulting in regulated expression of downstream coding regions. This review summarizes relevant findings in recent articles and outlines our current understanding of nascent peptide-induced ribosome stalling in regulating gene expression.
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163
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Onoue N, Yamashita Y, Nagao N, Goto DB, Onouchi H, Naito S. S-adenosyl-L-methionine induces compaction of nascent peptide chain inside the ribosomal exit tunnel upon translation arrest in the Arabidopsis CGS1 gene. J Biol Chem 2011; 286:14903-12. [PMID: 21335553 PMCID: PMC3083191 DOI: 10.1074/jbc.m110.211656] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Expression of the Arabidopsis CGS1 gene, encoding the first committed enzyme of methionine biosynthesis, is feedback-regulated in response to S-adenosyl-L-methionine (AdoMet) at the mRNA level. This regulation is first preceded by temporal arrest of CGS1 translation elongation at the Ser-94 codon. AdoMet is specifically required for this translation arrest, although the mechanism by which AdoMet acts with the CGS1 nascent peptide remained elusive. We report here that the nascent peptide of CGS1 is induced to form a compact conformation within the exit tunnel of the arrested ribosome in an AdoMet-dependent manner. Cysteine residues introduced into CGS1 nascent peptide showed reduced ability to react with polyethyleneglycol maleimide in the presence of AdoMet, consistent with a shift into the ribosomal exit tunnel. Methylation protection and UV cross-link assays of 28 S rRNA revealed that induced compaction of nascent peptide is associated with specific changes in methylation protection and UV cross-link patterns in the exit tunnel wall. A 14-residue stretch of amino acid sequence, termed the MTO1 region, has been shown to act in cis for CGS1 translation arrest and mRNA degradation. This regulation is lost in the presence of mto1 mutations, which cause single amino acid alterations within MTO1. In this study, both the induced peptide compaction and exit tunnel change were found to be disrupted by mto1 mutations. These results suggest that the MTO1 region participates in the AdoMet-induced arrest of CGS1 translation by mediating changes of the nascent peptide and the exit tunnel wall.
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Affiliation(s)
- Noriyuki Onoue
- Division of Life Science, Graduate School of Life Science, Hokkaido University, Sapporo 060-8589, Japan
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164
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Crystal structure of the synergistic antibiotic pair, lankamycin and lankacidin, in complex with the large ribosomal subunit. Proc Natl Acad Sci U S A 2011; 108:2717-22. [PMID: 21282615 DOI: 10.1073/pnas.1019406108] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The structures of the large ribosomal subunit of Deinococcus radiodurans (D50S) in complex with the antibiotic lankamycin (3.2 Å) and a double antibiotic complex of lankamycin and lankacidin C (3.45 Å) have been determined, in continuation of previous crystallographic studies on lankacidin-D50S complex. These two drugs have been previously reported to inhibit ribosomal function with mild synergistic effect. Lankamycin, a member of the macrolide family, binds in a similar manner to erythromycin. However, when in complex with lankacidin, lankamycin is located so that it can form interactions with lankacidin in the adjacent ribosomal binding site. When compared to the well-documented synergistic antibiotics, Streptogramins A and B, the pair of lankacidin and lankamycin bind in similar sites, the peptidyl transferase center and nascent peptide exit tunnel, respectively. Herein, we discuss the structural basis for antibiotic synergism and highlight the key factors involved in ribosomal inhibition.
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165
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Altuntop ME, Ly CT, Wang Y. Single-molecule study of ribosome hierarchic dynamics at the peptidyl transferase center. Biophys J 2011; 99:3002-9. [PMID: 21044598 DOI: 10.1016/j.bpj.2010.08.037] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2010] [Revised: 08/11/2010] [Accepted: 08/13/2010] [Indexed: 12/01/2022] Open
Abstract
During protein biosynthesis the ribosome moves along mRNA in steps of precisely three nucleotides. The mechanism for this ribosome motion remains elusive. Using a classification algorithm to sort single-molecule fluorescence resonance energy transfer data into subpopulations, we found that the ribosome dynamics detected at the peptidyl transferase center are highly inhomogeneous. The pretranslocation complex has at least four subpopulations that sample two hybrid states, whereas the posttranslocation complex is mainly static. We observed transitions among the ribosome subpopulations under various conditions, including 1), in the presence of EF-G; 2), spontaneously; 3), in different buffers, and 4), bound to antibiotics. Therefore, these subpopulations represent biologically active ribosomes. One key observation indicates that the Hy2 hybrid state only exists in a fluctuating ribosome subpopulation, which prompts us to propose that ribosome dynamics are hierarchically arranged. This proposal may have important implications for the regulation of cellular translation rates.
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Affiliation(s)
- Mediha Esra Altuntop
- Department of Biology and Biochemistry, University of Houston, Houston, Texas, USA
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166
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Bhushan S, Hoffmann T, Seidelt B, Frauenfeld J, Mielke T, Berninghausen O, Wilson DN, Beckmann R. SecM-stalled ribosomes adopt an altered geometry at the peptidyl transferase center. PLoS Biol 2011; 9:e1000581. [PMID: 21267063 PMCID: PMC3022528 DOI: 10.1371/journal.pbio.1000581] [Citation(s) in RCA: 108] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2010] [Accepted: 12/02/2010] [Indexed: 11/18/2022] Open
Abstract
A structure of a ribosome stalled during translation of the SecM peptide provides insight into the mechanism by which the large subunit active site is inactivated. As nascent polypeptide chains are synthesized, they pass through a tunnel in the large ribosomal subunit. Interaction between specific nascent chains and the ribosomal tunnel is used to induce translational stalling for the regulation of gene expression. One well-characterized example is the Escherichia coli SecM (secretion monitor) gene product, which induces stalling to up-regulate translation initiation of the downstream secA gene, which is needed for protein export. Although many of the key components of SecM and the ribosomal tunnel have been identified, understanding of the mechanism by which the peptidyl transferase center of the ribosome is inactivated has been lacking. Here we present a cryo-electron microscopy reconstruction of a SecM-stalled ribosome nascent chain complex at 5.6 Å. While no cascade of rRNA conformational changes is evident, this structure reveals the direct interaction between critical residues of SecM and the ribosomal tunnel. Moreover, a shift in the position of the tRNA–nascent peptide linkage of the SecM-tRNA provides a rationale for peptidyl transferase center silencing, conditional on the simultaneous presence of a Pro-tRNAPro in the ribosomal A-site. These results suggest a distinct allosteric mechanism of regulating translational elongation by the SecM stalling peptide. In all cells, ribosomes perform the job of making proteins. As the proteins are synthesized they pass through a tunnel in the ribosome, and some growing proteins interact with the tunnel, leading to stalling of protein synthesis. Here, we used cryo-electron microscopy to determine the structure of a ribosome stalled during the translation of the Escherichia coli secretion monitor (SecM) polypeptide chain. The structure reveals the path of the SecM peptide through the tunnel as well as the sites of interaction with the tunnel components. Interestingly, the structure shows a shift in the position of the transfer RNA (tRNA) to which the growing SecM polypeptide chain is attached. Since peptide bond formation during protein synthesis requires precise placement of the substrates, namely, the peptidyl-tRNA and the incoming amino acyl-tRNA, it is proposed that this shift in the SecM-tRNA explains why peptide bond formation cannot occur and translation stalls.
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Affiliation(s)
- Shashi Bhushan
- Gene Center and Department of Biochemistry, University of Munich, Munich, Germany
| | - Thomas Hoffmann
- Gene Center and Department of Biochemistry, University of Munich, Munich, Germany
| | - Birgit Seidelt
- Gene Center and Department of Biochemistry, University of Munich, Munich, Germany
| | - Jens Frauenfeld
- Gene Center and Department of Biochemistry, University of Munich, Munich, Germany
| | - Thorsten Mielke
- UltraStrukturNetzwerk, Max Planck Institute for Molecular Genetics, Berlin, Germany
- Institut für Medizinische Physik und Biophysik, Charité—Universitätsmedizin Berlin, Berlin, Germany
| | - Otto Berninghausen
- Gene Center and Department of Biochemistry, University of Munich, Munich, Germany
| | - Daniel N. Wilson
- Gene Center and Department of Biochemistry, University of Munich, Munich, Germany
- Center for Integrated Protein Science Munich (CiPSM), University of Munich, Munich, Germany
- * E-mail: (DNW); (RB)
| | - Roland Beckmann
- Gene Center and Department of Biochemistry, University of Munich, Munich, Germany
- Center for Integrated Protein Science Munich (CiPSM), University of Munich, Munich, Germany
- * E-mail: (DNW); (RB)
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167
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Bogdanov AA, Sumbatyan NV, Shishkina AV, Karpenko VV, Korshunova GA. Ribosomal tunnel and translation regulation. BIOCHEMISTRY (MOSCOW) 2011; 75:1501-16. [DOI: 10.1134/s0006297910130018] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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168
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Gurvich OL, Näsvall SJ, Baranov PV, Björk GR, Atkins JF. Two groups of phenylalanine biosynthetic operon leader peptides genes: a high level of apparently incidental frameshifting in decoding Escherichia coli pheL. Nucleic Acids Res 2010; 39:3079-92. [PMID: 21177642 PMCID: PMC3082878 DOI: 10.1093/nar/gkq1272] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The bacterial pheL gene encodes the leader peptide for the phenylalanine biosynthetic operon. Translation of pheL mRNA controls transcription attenuation and, consequently, expression of the downstream pheA gene. Fifty-three unique pheL genes have been identified in sequenced genomes of the gamma subdivision. There are two groups of pheL genes, both of which are short and contain a run(s) of phenylalanine codons at an internal position. One group is somewhat diverse and features different termination and 5'-flanking codons. The other group, mostly restricted to Enterobacteria and including Escherichia coli pheL, has a conserved nucleotide sequence that ends with UUC_CCC_UGA. When these three codons in E. coli pheL mRNA are in the ribosomal E-, P- and A-sites, there is an unusually high level, 15%, of +1 ribosomal frameshifting due to features of the nascent peptide sequence that include the penultimate phenylalanine. This level increases to 60% with a natural, heterologous, nascent peptide stimulator. Nevertheless, studies with different tRNA(Pro) mutants in Salmonella enterica suggest that frameshifting at the end of pheL does not influence expression of the downstream pheA. This finding of incidental, rather than utilized, frameshifting is cautionary for other studies of programmed frameshifting.
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Affiliation(s)
- Olga L Gurvich
- Department of Human Genetics, University of Utah, Salt Lake City, UT 84112-5330, USA
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169
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Bhushan S, Meyer H, Starosta AL, Becker T, Mielke T, Berninghausen O, Sattler M, Wilson DN, Beckmann R. Structural basis for translational stalling by human cytomegalovirus and fungal arginine attenuator peptide. Mol Cell 2010; 40:138-46. [PMID: 20932481 DOI: 10.1016/j.molcel.2010.09.009] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2010] [Revised: 05/28/2010] [Accepted: 07/30/2010] [Indexed: 10/19/2022]
Abstract
Specific regulatory nascent chains establish direct interactions with the ribosomal tunnel, leading to translational stalling. Despite a wealth of biochemical data, structural insight into the mechanism of translational stalling in eukaryotes is still lacking. Here we use cryo-electron microscopy to visualize eukaryotic ribosomes stalled during the translation of two diverse regulatory peptides: the fungal arginine attenuator peptide (AAP) and the human cytomegalovirus (hCMV) gp48 upstream open reading frame 2 (uORF2). The C terminus of the AAP appears to be compacted adjacent to the peptidyl transferase center (PTC). Both nascent chains interact with ribosomal proteins L4 and L17 at tunnel constriction in a distinct fashion. Significant changes at the PTC were observed: the eukaryotic-specific loop of ribosomal protein L10e establishes direct contact with the CCA end of the peptidyl-tRNA (P-tRNA), which may be critical for silencing of the PTC during translational stalling. Our findings provide direct structural insight into two distinct eukaryotic stalling processes.
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Affiliation(s)
- Shashi Bhushan
- Gene Center and Department of Biochemistry and Center for integrated Protein Science Munich, University of Munich, Feodor-Lynen-Strasse 25, 81377 Munich, Germany
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170
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Lucent D, Snow CD, Aitken CE, Pande VS. Non-bulk-like solvent behavior in the ribosome exit tunnel. PLoS Comput Biol 2010; 6:e1000963. [PMID: 20975935 PMCID: PMC2958802 DOI: 10.1371/journal.pcbi.1000963] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2010] [Accepted: 09/17/2010] [Indexed: 11/19/2022] Open
Abstract
As nascent proteins are synthesized by the ribosome, they depart via an exit tunnel running through the center of the large subunit. The exit tunnel likely plays an important part in various aspects of translation. Although water plays a key role in many bio-molecular processes, the nature of water confined to the exit tunnel has remained unknown. Furthermore, solvent in biological cavities has traditionally been characterized as either a continuous dielectric fluid, or a discrete tightly bound molecule. Using atomistic molecular dynamics simulations, we predict that the thermodynamic and kinetic properties of water confined within the ribosome exit tunnel are quite different from this simple two-state model. We find that the tunnel creates a complex microenvironment for the solvent resulting in perturbed rotational dynamics and heterogenous dielectric behavior. This gives rise to a very rugged solvation landscape and significantly retarded solvent diffusion. We discuss how this non-bulk-like solvent is likely to affect important biophysical processes such as sequence dependent stalling, co-translational folding, and antibiotic binding. We conclude with a discussion of the general applicability of these results to other biological cavities.
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Affiliation(s)
- Del Lucent
- Biophysics Program, Stanford University, Stanford, California, USA
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171
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Blanchard SC, Cooperman BS, Wilson DN. Probing translation with small-molecule inhibitors. ACTA ACUST UNITED AC 2010; 17:633-45. [PMID: 20609413 DOI: 10.1016/j.chembiol.2010.06.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2010] [Revised: 05/14/2010] [Accepted: 06/07/2010] [Indexed: 10/19/2022]
Abstract
The translational apparatus of the bacterial cell remains one of the principal targets of antibiotics for the clinical treatment of infection worldwide. Since the introduction of specific translation inhibitors into clinical practice in the late 1940s, intense efforts have been made to understand their precise mechanisms of action. Such research has often revealed significant and sometimes unexpected insights into many fundamental aspects of the translation mechanism. Central to progress in this area, high-resolution crystal structures of the bacterial ribosome identifying the sites of antibiotic binding are now available, which, together with recent developments in single-molecule and fast-kinetic approaches, provide an integrated view of the dynamic translation process. Assays employing these approaches and focusing on specific steps of the overall translation process are amenable for drug screening. Such assays, coupled with structural studies, have the potential not only to accelerate the discovery of novel and effective antimicrobial agents, but also to refine our understanding of the mechanisms of translation. Antibiotics often stabilize specific functional states of the ribosome and therefore allow distinct translation steps to be dissected in molecular detail.
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Affiliation(s)
- Scott C Blanchard
- Department of Physiology and Biophysics, Weill Cornell Medical College of Cornell University, New York, NY 10065, USA
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172
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Revisiting the structures of several antibiotics bound to the bacterial ribosome. Proc Natl Acad Sci U S A 2010; 107:17158-63. [PMID: 20876130 DOI: 10.1073/pnas.1008685107] [Citation(s) in RCA: 214] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The increasing prevalence of antibiotic-resistant pathogens reinforces the need for structures of antibiotic-ribosome complexes that are accurate enough to enable the rational design of novel ribosome-targeting therapeutics. Structures of many antibiotics in complex with both archaeal and eubacterial ribosomes have been determined, yet discrepancies between several of these models have raised the question of whether these differences arise from species-specific variations or from experimental problems. Our structure of chloramphenicol in complex with the 70S ribosome from Thermus thermophilus suggests a model for chloramphenicol bound to the large subunit of the bacterial ribosome that is radically different from the prevailing model. Further, our structures of the macrolide antibiotics erythromycin and azithromycin in complex with a bacterial ribosome are indistinguishable from those determined of complexes with the 50S subunit of Haloarcula marismortui, but differ significantly from the models that have been published for 50S subunit complexes of the eubacterium Deinococcus radiodurans. Our structure of the antibiotic telithromycin bound to the T. thermophilus ribosome reveals a lactone ring with a conformation similar to that observed in the H. marismortui and D. radiodurans complexes. However, the alkyl-aryl moiety is oriented differently in all three organisms, and the contacts observed with the T. thermophilus ribosome are consistent with biochemical studies performed on the Escherichia coli ribosome. Thus, our results support a mode of macrolide binding that is largely conserved across species, suggesting that the quality and interpretation of electron density, rather than species specificity, may be responsible for many of the discrepancies between the models.
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173
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Structures of the Escherichia coli ribosome with antibiotics bound near the peptidyl transferase center explain spectra of drug action. Proc Natl Acad Sci U S A 2010; 107:17152-7. [PMID: 20876128 DOI: 10.1073/pnas.1007988107] [Citation(s) in RCA: 330] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Differences between the structures of bacterial, archaeal, and eukaryotic ribosomes account for the selective action of antibiotics. Even minor variations in the structure of ribosomes of different bacterial species may lead to idiosyncratic, species-specific interactions of the drugs with their targets. Although crystallographic structures of antibiotics bound to the peptidyl transferase center or the exit tunnel of archaeal (Haloarcula marismortui) and bacterial (Deinococcus radiodurans) large ribosomal subunits have been reported, it remains unclear whether the interactions of antibiotics with these ribosomes accurately reflect those with the ribosomes of pathogenic bacteria. Here we report X-ray crystal structures of the Escherichia coli ribosome in complexes with clinically important antibiotics of four major classes, including the macrolide erythromycin, the ketolide telithromycin, the lincosamide clindamycin, and a phenicol, chloramphenicol, at resolutions of ∼3.3 Å-3.4 Å. Binding modes of three of these antibiotics show important variations compared to the previously determined structures. Biochemical and structural evidence also indicates that interactions of telithromycin with the E. coli ribosome more closely resembles drug binding to ribosomes of bacterial pathogens. The present data further argue that the identity of nucleotides 752, 2609, and 2055 of 23S ribosomal RNA explain in part the spectrum and selectivity of antibiotic action.
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174
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Peterson JH, Woolhead CA, Bernstein HD. The conformation of a nascent polypeptide inside the ribosome tunnel affects protein targeting and protein folding. Mol Microbiol 2010; 78:203-17. [PMID: 20804452 DOI: 10.1111/j.1365-2958.2010.07325.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
In this report, we describe insights into the function of the ribosome tunnel that were obtained through an analysis of an unusual 25 residue N-terminal motif (EspP(1-25) ) associated with the signal peptide of the Escherichia coli EspP protein. It was previously shown that EspP(1-25) inhibits signal peptide recognition by the signal recognition particle, and we now show that fusion of EspP(1-25) to a cytoplasmic protein causes it to aggregate. We obtained two lines of evidence that both of these effects are attributable to the conformation of EspP(1-25) inside the ribosome tunnel. First, we found that mutations in EspP(1-25) that abolished its effects on protein targeting and protein folding altered the cross-linking of short nascent chains to ribosomal components. Second, we found that a mutation in L22 that distorts the tunnel mimicked the effects of the EspP(1-25) mutations on protein biogenesis. Our results provide evidence that the conformation of a polypeptide inside the ribosome tunnel can influence protein folding under physiological conditions and suggest that ribosomal mutations might increase the solubility of at least some aggregation-prone proteins produced in E. coli.
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Affiliation(s)
- Janine H Peterson
- Genetics and Biochemistry Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0538, USA
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175
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Yamamoto T, Nishiyama A, Takano T, Yabe S, Higuchi W, Razvina O, Shi D. Community-acquired methicillin-resistant Staphylococcus aureus: community transmission, pathogenesis, and drug resistance. J Infect Chemother 2010; 16:225-54. [PMID: 20336341 PMCID: PMC7088255 DOI: 10.1007/s10156-010-0045-9] [Citation(s) in RCA: 105] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2009] [Indexed: 11/29/2022]
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) is able to persist not only in hospitals (with a high level of antimicrobial agent use) but also in the community (with a low level of antimicrobial agent use). The former is called hospital-acquired MRSA (HA-MRSA) and the latter community-acquired MRSA (CA-MRSA). It is believed MRSA clones are generated from S. aureus through insertion of the staphylococcal cassette chromosome mec (SCCmec), and outbreaks occur as they spread. Several worldwide and regional clones have been identified, and their epidemiological, clinical, and genetic characteristics have been described. CA-MRSA is likely able to survive in the community because of suitable SCCmec types (type IV or V), a clone-specific colonization/infection nature, toxin profiles (including Pantone-Valentine leucocidin, PVL), and narrow drug resistance patterns. CA-MRSA infections are generally seen in healthy children or young athletes, with unexpected cases of diseases, and also in elderly inpatients, occasionally surprising clinicians used to HA-MRSA infections. CA-MRSA spreads within families and close-contact groups or even through public transport, demonstrating transmission cores. Re-infection (including multifocal infection) frequently occurs, if the cores are not sought out and properly eradicated. Recently, attention has been given to CA-MRSA (USA300), which originated in the US, and is growing as HA-MRSA and also as a worldwide clone. CA-MRSA infection in influenza season has increasingly been noted as well. MRSA is also found in farm and companion animals, and has occasionally transferred to humans. As such, the epidemiological, clinical, and genetic behavior of CA-MRSA, a growing threat, is focused on in this study.
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Affiliation(s)
- Tatsuo Yamamoto
- Division of Bacteriology, Department of Infectious Disease Control and International Medicine, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
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176
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Vázquez-Laslop N, Ramu H, Klepacki D, Kannan K, Mankin AS. The key function of a conserved and modified rRNA residue in the ribosomal response to the nascent peptide. EMBO J 2010; 29:3108-17. [PMID: 20676057 DOI: 10.1038/emboj.2010.180] [Citation(s) in RCA: 121] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2010] [Accepted: 07/06/2010] [Indexed: 11/09/2022] Open
Abstract
The ribosome is able to monitor the structure of the nascent peptide and can stall in response to specific peptide sequences. Such programmed stalling is used for the regulation of gene expression. The molecular mechanisms of the nascent-peptide recognition and ribosome stalling are unknown. We identified the conserved and posttranscriptionally modified 23S rRNA nucleotide m(2)A2503 located at the entrance of the ribosome exit tunnel as a key component of the ribosomal response mechanism. A2503 mutations abolish nascent-peptide-dependent stalling at the leader cistrons of several inducible antibiotic resistance genes and at the secM regulatory gene. Remarkably, lack of the C2 methylation of A2503 significantly function induction of expression of the ermC gene, indicating that the functional role of posttranscriptional modification is to fine-tune ribosome-nascent peptide interactions. Structural and biochemical evidence suggest that m(2)A2503 may act in concert with the previously identified nascent-peptide sensor, A2062, in the ribosome exit tunnel to relay the stalling signal to the peptidyl transferase centre.
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Affiliation(s)
- Nora Vázquez-Laslop
- Center for Pharmaceutical Biotechnology, University of Illinois at Chicago, Chicago, IL, USA.
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177
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Whitford PC, Geggier P, Altman RB, Blanchard SC, Onuchic JN, Sanbonmatsu KY. Accommodation of aminoacyl-tRNA into the ribosome involves reversible excursions along multiple pathways. RNA (NEW YORK, N.Y.) 2010; 16:1196-204. [PMID: 20427512 PMCID: PMC2874171 DOI: 10.1261/rna.2035410] [Citation(s) in RCA: 156] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The ribosome is a massive ribonucleoprotein complex ( approximately 2.4 MDa) that utilizes large-scale structural fluctuations to produce unidirectional protein synthesis. Accommodation is a key conformational change during transfer RNA (tRNA) selection that allows movement of tRNA into the ribosome. Here, we address the structure-function relationship that governs accommodation using all-atom molecular simulations and single-molecule fluorescence resonance energy transfer (smFRET). Simulations that employ an all-atom, structure-based (Gō-like) model illuminate the interplay between configurational entropy and effective enthalpy during the accommodation process. This delicate balance leads to spontaneous reversible accommodation attempts, which are corroborated by smFRET measurements. The dynamics about the endpoints of accommodation (the A/T and A/A conformations) obtained from structure-based simulations are validated by multiple 100-200 ns explicit-solvent simulations (3.2 million atoms for a cumulative 1.4 micros), and previous crystallographic analysis. We find that the configurational entropy of the 3'-CCA end of aminoacyl-tRNA resists accommodation, leading to a multistep accommodation process that encompasses a distribution of parallel pathways. The calculated mechanism is robust across simulation methods and protocols, suggesting that the structure of the accommodation corridor imposes stringent limitations on the accessible pathways. The identified mechanism and observed parallel pathways establish an atomistic framework for interpreting a large body of biochemical data and demonstrate that conformational changes during translation occur through a stochastic trial-and-error process, rather than in concerted lock-step motions.
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MESH Headings
- Base Sequence
- Crystallography, X-Ray/methods
- Entropy
- Fluorescence Resonance Energy Transfer
- Models, Molecular
- Nucleic Acid Conformation
- Protein Biosynthesis
- RNA, Ribosomal, 16S/chemistry
- RNA, Ribosomal, 16S/genetics
- RNA, Ribosomal, 23S/chemistry
- RNA, Ribosomal, 23S/genetics
- RNA, Transfer/chemistry
- RNA, Transfer/genetics
- RNA, Transfer, Amino Acyl/chemistry
- RNA, Transfer, Amino Acyl/genetics
- RNA, Transfer, Amino Acyl/metabolism
- Ribonucleoproteins/metabolism
- Ribosomes/genetics
- Ribosomes/metabolism
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Affiliation(s)
- Paul C Whitford
- Center for Theoretical Biological Physics and Department of Physics, University of California, San Diego, La Jolla, California 92093, USA
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178
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Starosta AL, Karpenko VV, Shishkina AV, Mikolajka A, Sumbatyan NV, Schluenzen F, Korshunova GA, Bogdanov AA, Wilson DN. Interplay between the Ribosomal Tunnel, Nascent Chain, and Macrolides Influences Drug Inhibition. ACTA ACUST UNITED AC 2010; 17:504-14. [DOI: 10.1016/j.chembiol.2010.04.008] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2010] [Revised: 03/22/2010] [Accepted: 04/02/2010] [Indexed: 12/01/2022]
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179
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Sumbatyan NV, Kuznetsova IV, Karpenko VV, Fedorova NV, Chertkov VA, Korshunova GA, Bogdanov AA. Amino acid and peptide derivatives of the tylosin family of macrolide antibiotics modified by aldehyde function. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2010; 36:265-76. [DOI: 10.1134/s1068162010020159] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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180
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Chirkova A, Erlacher MD, Clementi N, Zywicki M, Aigner M, Polacek N. The role of the universally conserved A2450-C2063 base pair in the ribosomal peptidyl transferase center. Nucleic Acids Res 2010; 38:4844-55. [PMID: 20375101 PMCID: PMC2919715 DOI: 10.1093/nar/gkq213] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Despite the fact that all 23S rRNA nucleotides that build the ribosomal peptidyl transferase ribozyme are universally conserved, standard and atomic mutagenesis studies revealed the nucleobase identities being non-critical for catalysis. This indicates that these active site residues are highly conserved for functions distinct from catalysis. To gain insight into potential contributions, we have manipulated the nucleobases via an atomic mutagenesis approach and have utilized these chemically engineered ribosomes for in vitro translation reactions. We show that most of the active site nucleobases could be removed without significant effects on polypeptide production. Our data however highlight the functional importance of the universally conserved non-Watson-Crick base pair at position A2450-C2063. Modifications that disrupt this base pair markedly impair translation activities, while having little effects on peptide bond formation, tRNA drop-off and ribosome-dependent EF-G GTPase activity. Thus it seems that disruption of the A2450-C2063 pair inhibits a reaction following transpeptidation and EF-G action during the elongation cycle. Cumulatively our data are compatible with the hypothesis that the integrity of this A-C wobble base pair is essential for effective tRNA translocation through the peptidyl transferase center during protein synthesis.
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Affiliation(s)
- Anna Chirkova
- Innsbruck Biocenter, Medical University Innsbruck, Division of Genomics and RNomics, Innsbruck, Austria
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181
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α-Helical nascent polypeptide chains visualized within distinct regions of the ribosomal exit tunnel. Nat Struct Mol Biol 2010; 17:313-7. [DOI: 10.1038/nsmb.1756] [Citation(s) in RCA: 172] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2009] [Accepted: 12/02/2009] [Indexed: 11/08/2022]
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182
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The structure of ribosome-lankacidin complex reveals ribosomal sites for synergistic antibiotics. Proc Natl Acad Sci U S A 2010; 107:1983-8. [PMID: 20080686 PMCID: PMC2804743 DOI: 10.1073/pnas.0914100107] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Crystallographic analysis revealed that the 17-member polyketide antibiotic lankacidin produced by Streptomyces rochei binds at the peptidyl transferase center of the eubacterial large ribosomal subunit. Biochemical and functional studies verified this finding and showed interference with peptide bond formation. Chemical probing indicated that the macrolide lankamycin, a second antibiotic produced by the same species, binds at a neighboring site, at the ribosome exit tunnel. These two antibiotics can bind to the ribosome simultaneously and display synergy in inhibiting bacterial growth. The binding site of lankacidin and lankamycin partially overlap with the binding site of another pair of synergistic antibiotics, the streptogramins. Thus, at least two pairs of structurally dissimilar compounds have been selected in the course of evolution to act synergistically by targeting neighboring sites in the ribosome. These results underscore the importance of the corresponding ribosomal sites for development of clinically relevant synergistic antibiotics and demonstrate the utility of structural analysis for providing new directions for drug discovery.
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183
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Ito K, Chiba S, Pogliano K. Divergent stalling sequences sense and control cellular physiology. Biochem Biophys Res Commun 2010; 393:1-5. [PMID: 20117091 DOI: 10.1016/j.bbrc.2010.01.073] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2010] [Accepted: 01/16/2010] [Indexed: 10/19/2022]
Abstract
Recent studies have identified several amino acid sequences that interact with the ribosomal interior components and arrest their own elongation. Whereas stalling of the inducible class depends on specific low-molecular weight compounds, that of the intrinsic class is released when the nascent chain is transported across or inserted into the membrane. The stalled ribosome alters messenger RNA secondary structure and thereby contributes to regulation of the cis-located target gene expression at different levels. The stalling sequences are divergent but likely to utilize non-uniform nature of the peptide bond formation reactions and are recruited relatively recently to different biological systems, possibly including those to be identified in forthcoming studies.
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Affiliation(s)
- Koreaki Ito
- Faculty of Life Sciences, Kyoto Sangyo University, Motoyama, Kamigamo, Kita-Ku, Kyoto 603-8555, Japan.
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184
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Romby P, Charpentier E. An overview of RNAs with regulatory functions in gram-positive bacteria. Cell Mol Life Sci 2010; 67:217-37. [PMID: 19859665 PMCID: PMC11115938 DOI: 10.1007/s00018-009-0162-8] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2009] [Revised: 09/07/2009] [Accepted: 09/23/2009] [Indexed: 11/26/2022]
Abstract
During the last decade, RNA molecules with regulatory functions on gene expression have benefited from a renewed interest. In bacteria, recent high throughput computational and experimental approaches have led to the discovery that 10-20% of all genes code for RNAs with critical regulatory roles in metabolic, physiological and pathogenic processes. The trans-acting RNAs comprise the noncoding RNAs, RNAs with a short open reading frame and antisense RNAs. Many of these RNAs act through binding to their target mRNAs while others modulate protein activity or target DNA. The cis-acting RNAs include regulatory regions of mRNAs that can respond to various signals. These RNAs often provide the missing link between sensing changing conditions in the environment and fine-tuning the subsequent biological responses. Information on their various functions and modes of action has been well documented for gram-negative bacteria. Here, we summarize the current knowledge of regulatory RNAs in gram-positive bacteria.
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Affiliation(s)
- Pascale Romby
- Architecture et Réactivité de l’ARN, Université de Strasbourg, CNRS, IBMC, 15 rue René Descartes, 67084 Strasbourg, France
| | - Emmanuelle Charpentier
- Max F. Perutz Laboratories, University of Vienna, Dr. Bohrgasse 9, 1030 Vienna, Austria
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, 90187 Umeå, Sweden
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185
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Yao S, Sharp JS, Bechhofer DH. Bacillus subtilis RNase J1 endonuclease and 5' exonuclease activities in the turnover of DeltaermC mRNA. RNA (NEW YORK, N.Y.) 2009; 15:2331-9. [PMID: 19850915 PMCID: PMC2779671 DOI: 10.1261/rna.1749109] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
RNase J1, a ribonuclease with 5' exonuclease and endonuclease activities, is an important factor in Bacillus subtilis mRNA decay. A model for RNase J1 endonuclease activity in mRNA turnover has RNase J1 binding to the 5' end and tracking to a target site downstream, where it makes a decay-initiating cleavage. The upstream fragment from this cleavage is degraded by 3' exonucleases; the downstream fragment is degraded by RNase J1 5' exonuclease activity. Previously, DeltaermC mRNA was used to show 5'-end dependence of mRNA turnover. Here we used DeltaermC mRNA to probe RNase J1-dependent degradation, and the results were consistent with aspects of the model. DeltaermC mRNA showed increased stability in a mutant strain that contained a reduced level of RNase J1. In agreement with the tracking concept, insertion of a strong stem-loop structure at +65 resulted in increased stability. Weakening this stem-loop structure resulted in reversion to wild-type stability. RNA fragments containing the 3' end were detected in a strain with reduced RNase J1 expression, but were undetectable in the wild type. The 5' ends of these fragments mapped to the upstream side of predicted stem-loop structures, consistent with an impediment to RNase J1 5' exonuclease processivity. A DeltaermC mRNA deletion analysis suggested that decay-initiating endonuclease cleavage could occur at several sites near the 3' end. However, even in the absence of these sites, stability was further increased in a strain with reduced RNase J1, suggesting alternate pathways for decay that could include exonucleolytic decay from the 5' end.
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Affiliation(s)
- Shiyi Yao
- Department of Pharmacology and Systems Therapeutics, Mount Sinai School of Medicine of New York University, New York, New York 10029, USA
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186
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187
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Seidelt B, Innis CA, Wilson DN, Gartmann M, Armache JP, Villa E, Trabuco LG, Becker T, Mielke T, Schulten K, Steitz TA, Beckmann R. Structural insight into nascent polypeptide chain-mediated translational stalling. Science 2009; 326:1412-5. [PMID: 19933110 DOI: 10.1126/science.1177662] [Citation(s) in RCA: 214] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Expression of the Escherichia coli tryptophanase operon depends on ribosome stalling during translation of the upstream TnaC leader peptide, a process for which interactions between the TnaC nascent chain and the ribosomal exit tunnel are critical. We determined a 5.8 angstrom-resolution cryo-electron microscopy and single-particle reconstruction of a ribosome stalled during translation of the tnaC leader gene. The nascent chain was extended within the exit tunnel, making contacts with ribosomal components at distinct sites. Upon stalling, two conserved residues within the peptidyltransferase center adopted conformations that preclude binding of release factors. We propose a model whereby interactions within the tunnel are relayed to the peptidyltransferase center to inhibit translation. Moreover, we show that nascent chains adopt distinct conformations within the ribosomal exit tunnel.
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Affiliation(s)
- Birgit Seidelt
- Gene Center and Center for Integrated Protein Science Munich (CIPSM), Department for Chemistry and Biochemistry, University of Munich, Feodor-Lynen-Strasse 25, 81377 Munich, Germany
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188
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Tanner DR, Cariello DA, Woolstenhulme CJ, Broadbent MA, Buskirk AR. Genetic identification of nascent peptides that induce ribosome stalling. J Biol Chem 2009; 284:34809-18. [PMID: 19840930 DOI: 10.1074/jbc.m109.039040] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Several nascent peptides stall ribosomes during their own translation in both prokaryotes and eukaryotes. Leader peptides that induce stalling can regulate downstream gene expression. Interestingly, stalling peptides show little sequence similarity and interact with the ribosome through distinct mechanisms. To explore the scope of regulation by stalling peptides and to better understand the mechanism of stalling, we identified and characterized new examples from random libraries. We created a genetic selection that ties the life of Escherichia coli cells to stalling at a specific site. This selection relies on the natural bacterial system that rescues arrested ribosomes. We altered transfer-messenger RNA, a key component of this rescue system, to direct the completion of a necessary protein if and only if stalling occurs. We identified three classes of stalling peptides: C-terminal Pro residues, SecM-like peptides, and the novel stalling sequence FXXYXIWPP. Like the leader peptides SecM and TnaC, the FXXYXIWPP peptide induces stalling efficiently by inhibiting peptidyl transfer. The nascent peptide exit tunnel and peptidyltransferase center are implicated in this stalling event, although mutations in the ribosome affect stalling on SecM and FXXYXIWPP differently. We conclude that ribosome stalling can be caused by numerous sequences and is more common than previously believed.
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Affiliation(s)
- Douglas R Tanner
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602, USA
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189
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Chiba S, Lamsa A, Pogliano K. A ribosome-nascent chain sensor of membrane protein biogenesis in Bacillus subtilis. EMBO J 2009; 28:3461-75. [PMID: 19779460 DOI: 10.1038/emboj.2009.280] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2009] [Accepted: 08/12/2009] [Indexed: 11/09/2022] Open
Abstract
Proteins in the YidC/Oxa1/Alb3 family have essential functions in membrane protein insertion and folding. Bacillus subtilis encodes two YidC homologs, one that is constitutively expressed (spoIIIJ/yidC1) and a second (yqjG/yidC2) that is induced in spoIIIJ mutants. Regulated induction of yidC2 allows B. subtilis to maintain capacity of the membrane protein insertion pathway. We here show that a gene located upstream of yidC2 (mifM/yqzJ) serves as a sensor of SpoIIIJ activity that regulates yidC2 translation. Decreased SpoIIIJ levels or deletion of the MifM transmembrane domain arrests mifM translation and unfolds an mRNA hairpin that otherwise blocks initiation of yidC2 translation. This regulated translational arrest and yidC2 induction require a specific interaction between the MifM C-terminus and the ribosomal polypeptide exit tunnel. MifM therefore acts as a ribosome-nascent chain complex rather than as a fully synthesized protein. B. subtilis MifM and the previously described secretion monitor SecM in Escherichia coli thereby provide examples of the parallel evolution of two regulatory nascent chains that monitor different protein export pathways by a shared molecular mechanism.
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Affiliation(s)
- Shinobu Chiba
- Division of Biological Sciences, University of California, San Diego, CA, USA
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190
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Yeh E, Pinsky BA, Banaei N, Baron EJ. Hair sheep blood, citrated or defibrinated, fulfills all requirements of blood agar for diagnostic microbiology laboratory tests. PLoS One 2009; 4:e6141. [PMID: 19578541 PMCID: PMC2700971 DOI: 10.1371/journal.pone.0006141] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2009] [Accepted: 05/22/2009] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND Blood agar is used for the identification and antibiotic susceptibility testing of many bacterial pathogens. In the developing world, microbiologists use human blood agar because of the high cost and inhospitable conditions for raising wool sheep or horses to supply blood. Many pathogens either fail to grow entirely or exhibit morphologies and hemolytic patterns on human blood agar that confound colony recognition. Furthermore, human blood can be hazardous to handle due to HIV and hepatitis. This study investigated whether blood from hair sheep, a hardy, low-maintenance variety of sheep adapted for hot climates, was suitable for routine clinical microbiology studies. METHODS AND FINDINGS Hair sheep blood obtained by jugular venipuncture was anticoagulated by either manual defibrination or collection in human blood bank bags containing citrate-phosphate-dextrose. Trypticase soy 5% blood agar was made from both forms of hair sheep blood and commercial defibrinated wool sheep blood. Growth characteristics, colony morphologies, and hemolytic patterns of selected human pathogens, including several streptococcal species, were evaluated. Specialized identification tests, including CAMP test, reverse CAMP test, and satellite colony formation with Haemophilus influenzae and Abiotrophia defectiva were also performed. Mueller-Hinton blood agar plates prepared from the three blood types were compared in antibiotic susceptibility tests by disk diffusion and E-test. CONCLUSIONS The results of all studies showed that blood agar prepared from citrated hair sheep blood is suitable for microbiological tests used in routine identification and susceptibility profiling of human pathogens. The validation of citrated hair sheep blood eliminates the labor-intensive and equipment-requiring process of manual defibrination. Use of hair sheep blood, in lieu of human blood currently used by many developing world laboratories and as an alternative to cost-prohibitive commercial sheep blood, offers the opportunity to dramatically improve the safety and accuracy of laboratory diagnosis of pathogenic bacteria in resource-poor countries.
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Affiliation(s)
- Ellen Yeh
- Department of Pathology, Stanford University School of Medicine, Stanford, California, United States of America
| | - Benjamin A. Pinsky
- Department of Pathology, Stanford University School of Medicine, Stanford, California, United States of America
| | - Niaz Banaei
- Department of Pathology, Stanford University School of Medicine, Stanford, California, United States of America
- Clinical Microbiology Laboratory, Stanford Hospital and Clinics, Palo Alto, California, United States of America
| | - Ellen Jo Baron
- Department of Pathology, Stanford University School of Medicine, Stanford, California, United States of America
- Clinical Microbiology Laboratory, Stanford Hospital and Clinics, Palo Alto, California, United States of America
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191
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Hummel M, Rahmani F, Smeekens S, Hanson J. Sucrose-mediated translational control. ANNALS OF BOTANY 2009; 104:1-7. [PMID: 19376782 PMCID: PMC2706714 DOI: 10.1093/aob/mcp086] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2008] [Revised: 12/18/2008] [Accepted: 03/05/2009] [Indexed: 05/20/2023]
Abstract
BACKGROUND Environmental factors greatly impact plant gene expression and concentrations of cellular metabolites such as sugars and amino acids. The changed metabolite concentrations affect the expression of many genes both transcriptionally and post-transcriptionally. RECENT PROGRESS Sucrose acts as a signalling molecule in the control of translation of the S1 class basic leucine zipper transcription factor (bZIP) genes. In these genes the main bZIP open reading frames (ORFs) are preceded by upstream open reading frames (uORFs). The presence of uORFs generally inhibits translation of the following ORF but can also be instrumental in specific translational control. bZIP11, a member of the S1 class bZIP genes, harbours four uORFs of which uORF2 is required for translational control in response to sucrose concentrations. This uORF encodes the Sucrose Control peptide (SC-peptide), which is evolutionarily conserved among all S1 class bZIP genes in different plant species. Arabidopsis thaliana bZIP11 and related bZIP genes seem to be important regulators of metabolism. These proteins are targets of the Snf1-related protein kinase 1 (SnRK1) KIN10 and KIN11, which are responsive to energy deprivation as well as to various stresses. In response to energy deprivation, ribosomal biogenesis is repressed to preserve cellular function and maintenance. Other key regulators of ribosomal biogenesis such as the protein kinase Target of Rapamycin (TOR) are tightly regulated in response to stress. CONCLUSIONS Plants use translational control of gene expression to optimize growth and development in response to stress as well as to energy deprivation. This Botanical Briefing discusses the role of sucrose signalling in the translational control of bZIP11 and the regulation of ribosomal biogenesis in response to metabolic changes and stress conditions.
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Affiliation(s)
- Maureen Hummel
- Molecular Plant Physiology, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Fatima Rahmani
- Molecular Plant Physiology, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Sjef Smeekens
- Molecular Plant Physiology, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
- Centre for BioSystems Genomics, POB 98, 6700 AB, Wageningen, The Netherlands
| | - Johannes Hanson
- Molecular Plant Physiology, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
- Centre for BioSystems Genomics, POB 98, 6700 AB, Wageningen, The Netherlands
- For correspondence. Email
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192
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Abstract
Many bioactive compounds contain as part of their molecules one or more deoxysugar units. Their presence in the final compound is generally necessary for biological activity. These sugars derive from common monosaccharides, like d-glucose, which have lost one or more hydroxyl groups (monodeoxysugars, dideoxysugars, trideoxysugars) during their biosynthesis. These deoxysugars are transferred to the final molecule by the action of a glycosyltransferase. Here, we first summarize the different biosynthetic steps required for the generation of the different families of deoxysugars, including those containing extra methyl or amino groups, or tailoring modifications of the glycosylated compounds. We then give examples of several strategies for modification of the glycosylation pattern of a given bioactive compound: inactivation of genes involved in the biosynthesis of deoxysugars; heterologous expression of genes for the biosynthesis or transfer of a specific deoxysugar; and combinatorial biosynthesis (including the use of gene cassette plasmids). Finally, we report techniques for the isolation and detection of the new glycosylated derivatives generated using these strategies.
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Affiliation(s)
- Felipe Lombó
- Departamento de Biología Funcional and Instituto Universitario de Oncología del Principado de Asturias (I.U.O.P.A), Universidad de Oviedo, Oviedo, Spain
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193
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Yap MN, Bernstein HD. The plasticity of a translation arrest motif yields insights into nascent polypeptide recognition inside the ribosome tunnel. Mol Cell 2009; 34:201-11. [PMID: 19394297 DOI: 10.1016/j.molcel.2009.04.002] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2008] [Revised: 02/20/2009] [Accepted: 04/03/2009] [Indexed: 11/19/2022]
Abstract
The recognition of a C-terminal motif in E. coli SecM ((150)FXXXXWIXXXXGIRAGP(166)) inside the ribosome tunnel causes translation arrest, but the mechanism of recognition is unknown. Whereas single mutations in this motif impair recognition, we demonstrate that new arrest-inducing peptides can be created through remodeling of the SecM C terminus. We found that R163 is indispensable but that flanking residues that vary in number and position play an important secondary role in translation arrest. The observation that individual SecM variants showed a distinct pattern of crosslinking to ribosomal proteins suggests that each peptide adopts a unique conformation inside the tunnel. Based on the results, we propose that translation arrest occurs when the peptide conformation specified by flanking residues moves R163 into a precise intratunnel location. Our data indicate that translation arrest results from extensive communication between SecM and the tunnel and help to explain the striking diversity of arrest-inducing peptides found throughout nature.
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Affiliation(s)
- Mee-Ngan Yap
- Genetics and Biochemistry Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
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194
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Moroder H, Steger J, Graber D, Fauster K, Trappl K, Marquez V, Polacek N, Wilson D, Micura R. Non-Hydrolyzable RNA-Peptide Conjugates: A Powerful Advance in the Synthesis of Mimics for 3′-Peptidyl tRNA Termini. Angew Chem Int Ed Engl 2009. [DOI: 10.1002/ange.200900939] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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195
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Moroder H, Steger J, Graber D, Fauster K, Trappl K, Marquez V, Polacek N, Wilson D, Micura R. Non-Hydrolyzable RNA-Peptide Conjugates: A Powerful Advance in the Synthesis of Mimics for 3′-Peptidyl tRNA Termini. Angew Chem Int Ed Engl 2009; 48:4056-60. [DOI: 10.1002/anie.200900939] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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196
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Bechhofer DH. Messenger RNA decay and maturation in Bacillus subtilis. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2009; 85:231-73. [PMID: 19215774 DOI: 10.1016/s0079-6603(08)00806-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
Our understanding of the ribonucleases that act to process and turn over RNA in Bacillus subtilis, a model Gram-positive organism, has increased greatly in recent years. This chapter discusses characteristics of B. subtilis ribonucleases that have been shown to participate in messenger RNA maturation and decay. Distinct features of a recently discovered ribonuclease, RNase J1, are reviewed, and are put in the context of a mechanism for the mRNA decay process in B. subtilis that differs greatly from the classical model developed for E. coli. This chapter is divided according to three parts of an mRNA-5' end, body, and 3' end-that could theoretically serve as sites for initiation of decay. How 5'-proximal elements affect mRNA half-life, and especially how these elements interface with RNase J1, forms the basis for a set of "rules" that may be useful in predicting mRNA stability.
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Affiliation(s)
- David H Bechhofer
- Department of Pharmacology and Systems Therapeutics, Mount Sinai School of Medicine of New York University, New York, NY 10029, USA
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197
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23S rRNA nucleotides in the peptidyl transferase center are essential for tryptophanase operon induction. J Bacteriol 2009; 191:3445-50. [PMID: 19329641 DOI: 10.1128/jb.00096-09] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Distinct features of the ribosomal peptide exit tunnel are known to be essential for recognition of specific amino acids of a nascent peptidyl-tRNA. Thus, a tryptophan residue at position 12 of the peptidyl-tRNA TnaC-tRNA(Pro) leads to the creation of a free tryptophan binding site within the ribosome at which bound tryptophan inhibits normal ribosome functions. The ribosomal processes that are inhibited are hydrolysis of TnaC-tRNA(Pro) by release factor 2 and peptidyl transfer of TnaC of TnaC-tRNA(Pro) to puromycin. These events are normally performed in the ribosomal peptidyl transferase center. In the present study, changes of 23S rRNA nucleotides in the 2585 region of the peptidyl transferase center, G2583A and U2584C, were observed to reduce maximum induction of tna operon expression by tryptophan in vivo without affecting the concentration of tryptophan necessary to obtain 50% induction. The growth rate of strains with ribosomes with either of these changes was not altered appreciably. In vitro analyses with mutant ribosomes with these changes showed that tryptophan was not as efficient in protecting TnaC-tRNA(Pro) from puromycin action as wild-type ribosomes. However, added tryptophan did prevent sparsomycin action as it normally does with wild-type ribosomes. These findings suggest that these two mutational changes act by reducing the ability of ribosome-bound tryptophan to inhibit peptidyl transferase activity rather than by reducing the ability of the ribosome to bind tryptophan. Thus, the present study identifies specific nucleotides within the ribosomal peptidyl transferase center that appear to be essential for effective tryptophan induction of tna operon expression.
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Wekselman I, Davidovich C, Agmon I, Zimmerman E, Rozenberg H, Bashan A, Berisio R, Yonath A. Ribosome's mode of function: myths, facts and recent results. J Pept Sci 2009; 15:122-30. [DOI: 10.1002/psc.1077] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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199
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Gopinath SCB. Mapping of RNA-protein interactions. Anal Chim Acta 2009; 636:117-28. [PMID: 19264161 DOI: 10.1016/j.aca.2009.01.052] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2008] [Revised: 01/26/2009] [Accepted: 01/26/2009] [Indexed: 12/19/2022]
Abstract
RNA-protein interactions are important biological events that perform multiple functions in all living organisms. The wide range of RNA interactions demands diverse conformations to provide contacts for the selective recognition of proteins. Various analytical procedures are presently available for quantitative analyses of RNA-protein complexes, but analytical-based mapping of these complexes is essential to probe specific interactions. In this overview, interactions of functional RNAs and RNA-aptamers with target proteins are discussed by means of mapping strategies.
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Affiliation(s)
- Subash Chandra Bose Gopinath
- Institute for Biological Resources and Functions & Center for Applied Near Field Optics Research (CAN-FOR), National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba City 305-8562, Ibaraki, Japan
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Ribosome: an Ancient Cellular Nano-Machine for Genetic Code Translation. NATO SCIENCE FOR PEACE AND SECURITY SERIES B: PHYSICS AND BIOPHYSICS 2009. [DOI: 10.1007/978-90-481-2368-1_8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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