1
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Dinh N, Bonnefoy N. Schizosaccharomyces pombe as a fundamental model for research on mitochondrial gene expression: Progress, achievements and outlooks. IUBMB Life 2024; 76:397-419. [PMID: 38117001 DOI: 10.1002/iub.2801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Accepted: 11/17/2023] [Indexed: 12/21/2023]
Abstract
Schizosaccharomyces pombe (fission yeast) is an attractive model for mitochondrial research. The organism resembles human cells in terms of mitochondrial inheritance, mitochondrial transport, sugar metabolism, mitogenome structure and dependence of viability on the mitogenome (the petite-negative phenotype). Transcriptions of these genomes produce only a few polycistronic transcripts, which then undergo processing as per the tRNA punctuation model. In general, the machinery for mitochondrial gene expression is structurally and functionally conserved between fission yeast and humans. Furthermore, molecular research on S. pombe is supported by a considerable number of experimental techniques and database resources. Owing to these advantages, fission yeast has significantly contributed to biomedical and fundamental research. Here, we review the current state of knowledge regarding S. pombe mitochondrial gene expression, and emphasise the pertinence of fission yeast as both a model and tool, especially for studies on mitochondrial translation.
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Affiliation(s)
- Nhu Dinh
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, 91198 Gif-sur-Yvette cedex, France
| | - Nathalie Bonnefoy
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, 91198 Gif-sur-Yvette cedex, France
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2
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Girodat D, Wieden HJ, Blanchard SC, Sanbonmatsu KY. Geometric alignment of aminoacyl-tRNA relative to catalytic centers of the ribosome underpins accurate mRNA decoding. Nat Commun 2023; 14:5582. [PMID: 37696823 PMCID: PMC10495418 DOI: 10.1038/s41467-023-40404-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Accepted: 07/27/2023] [Indexed: 09/13/2023] Open
Abstract
Accurate protein synthesis is determined by the two-subunit ribosome's capacity to selectively incorporate cognate aminoacyl-tRNA for each mRNA codon. The molecular basis of tRNA selection accuracy, and how fidelity can be affected by antibiotics, remains incompletely understood. Using molecular simulations, we find that cognate and near-cognate tRNAs delivered to the ribosome by Elongation Factor Tu (EF-Tu) can follow divergent pathways of motion into the ribosome during both initial selection and proofreading. Consequently, cognate aa-tRNAs follow pathways aligned with the catalytic GTPase and peptidyltransferase centers of the large subunit, while near-cognate aa-tRNAs follow pathways that are misaligned. These findings suggest that differences in mRNA codon-tRNA anticodon interactions within the small subunit decoding center, where codon-anticodon interactions occur, are geometrically amplified over distance, as a result of this site's physical separation from the large ribosomal subunit catalytic centers. These insights posit that the physical size of both tRNA and ribosome are key determinants of the tRNA selection fidelity mechanism.
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Affiliation(s)
- Dylan Girodat
- Theoretical Biology and Biophysics, Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
- Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, AR, 72701, USA
| | - Hans-Joachim Wieden
- Department of Microbiology, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada
| | - Scott C Blanchard
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA.
| | - Karissa Y Sanbonmatsu
- Theoretical Biology and Biophysics, Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA.
- New Mexico Consortium, Los Alamos, NM, 87545, USA.
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3
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McDonnell CM, Ghanim M, Mike Southern J, Kelly VP, Connon SJ. De-novo designed β-lysine derivatives can both augment and diminish the proliferation rates of E. coli through the action of Elongation Factor P. Bioorg Med Chem Lett 2022; 59:128545. [PMID: 35032607 DOI: 10.1016/j.bmcl.2022.128545] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 01/06/2022] [Accepted: 01/09/2022] [Indexed: 12/20/2022]
Abstract
An investigation into the effect of modified β -lysines on the growth rates of eubacterial cells is reported. It is shown that the effects observed are due to the post translational modification of Elongation Factor P (EFP) with these compounds catalysed by PoxA. PoxA was found to be remarkably promiscuous, which allowed the activity of a wide range of exogenous β -lysines to be examined. Two chain-elongated β -lysine derivatives which differ in aminoalkyl chain length by only 2 carbon units exhibited opposing biological activities - one promoting growth and the other retarding it. Both compounds were shown to operate through modification of EFP.
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Affiliation(s)
- Ciara M McDonnell
- School of Chemistry, Trinity Biomedical Sciences Institute, Trinity College Dublin 152-160 Pearse Street, Dublin 2, Ireland
| | - Magda Ghanim
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin 152-160 Pearse Street, Dublin 2, Ireland
| | - J Mike Southern
- School of Chemistry, Trinity Biomedical Sciences Institute, Trinity College Dublin 152-160 Pearse Street, Dublin 2, Ireland.
| | - Vincent P Kelly
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin 152-160 Pearse Street, Dublin 2, Ireland.
| | - Stephen J Connon
- School of Chemistry, Trinity Biomedical Sciences Institute, Trinity College Dublin 152-160 Pearse Street, Dublin 2, Ireland.
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4
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Tsai K, Stojković V, Noda-Garcia L, Young ID, Myasnikov AG, Kleinman J, Palla A, Floor SN, Frost A, Fraser JS, Tawfik DS, Fujimori DG. Directed evolution of the rRNA methylating enzyme Cfr reveals molecular basis of antibiotic resistance. eLife 2022; 11:e70017. [PMID: 35015630 PMCID: PMC8752094 DOI: 10.7554/elife.70017] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Accepted: 11/25/2021] [Indexed: 12/11/2022] Open
Abstract
Alteration of antibiotic binding sites through modification of ribosomal RNA (rRNA) is a common form of resistance to ribosome-targeting antibiotics. The rRNA-modifying enzyme Cfr methylates an adenosine nucleotide within the peptidyl transferase center, resulting in the C-8 methylation of A2503 (m8A2503). Acquisition of cfr results in resistance to eight classes of ribosome-targeting antibiotics. Despite the prevalence of this resistance mechanism, it is poorly understood whether and how bacteria modulate Cfr methylation to adapt to antibiotic pressure. Moreover, direct evidence for how m8A2503 alters antibiotic binding sites within the ribosome is lacking. In this study, we performed directed evolution of Cfr under antibiotic selection to generate Cfr variants that confer increased resistance by enhancing methylation of A2503 in cells. Increased rRNA methylation is achieved by improved expression and stability of Cfr through transcriptional and post-transcriptional mechanisms, which may be exploited by pathogens under antibiotic stress as suggested by natural isolates. Using a variant that achieves near-stoichiometric methylation of rRNA, we determined a 2.2 Å cryo-electron microscopy structure of the Cfr-modified ribosome. Our structure reveals the molecular basis for broad resistance to antibiotics and will inform the design of new antibiotics that overcome resistance mediated by Cfr.
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Affiliation(s)
- Kaitlyn Tsai
- Department of Cellular and Molecular Pharmacology, University of California San FranciscoSan FranciscoUnited States
| | - Vanja Stojković
- Department of Cellular and Molecular Pharmacology, University of California San FranciscoSan FranciscoUnited States
| | - Lianet Noda-Garcia
- Department of Biomolecular Sciences, Weizmann Institute of ScienceRehovotIsrael
| | - Iris D Young
- Department of Bioengineering and Therapeutic Sciences, University of California San FranciscoSan FranciscoUnited States
| | - Alexander G Myasnikov
- Department of Biochemistry and Biophysics, University of California San FranciscoSan FranciscoUnited States
| | - Jordan Kleinman
- Department of Cellular and Molecular Pharmacology, University of California San FranciscoSan FranciscoUnited States
| | - Ali Palla
- Department of Cellular and Molecular Pharmacology, University of California San FranciscoSan FranciscoUnited States
| | - Stephen N Floor
- Helen Diller Family Comprehensive Cancer Center, University of California San FranciscoSan FranciscoUnited States
- Department of Cell and Tissue Biology, University of California San FranciscoSan FranciscoUnited States
| | - Adam Frost
- Department of Biochemistry and Biophysics, University of California San FranciscoSan FranciscoUnited States
- Quantitative Biosciences Institute, University of California San FranciscoSan FranciscoUnited States
| | - James S Fraser
- Department of Bioengineering and Therapeutic Sciences, University of California San FranciscoSan FranciscoUnited States
- Quantitative Biosciences Institute, University of California San FranciscoSan FranciscoUnited States
| | - Dan S Tawfik
- Department of Biomolecular Sciences, Weizmann Institute of ScienceRehovotIsrael
| | - Danica Galonić Fujimori
- Department of Cellular and Molecular Pharmacology, University of California San FranciscoSan FranciscoUnited States
- Quantitative Biosciences Institute, University of California San FranciscoSan FranciscoUnited States
- Department of Pharmaceutical Chemistry, University of California San FranciscoSan FranciscoUnited States
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5
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Shirokikh NE. Translation complex stabilization on messenger RNA and footprint profiling to study the RNA responses and dynamics of protein biosynthesis in the cells. Crit Rev Biochem Mol Biol 2021; 57:261-304. [PMID: 34852690 DOI: 10.1080/10409238.2021.2006599] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
During protein biosynthesis, ribosomes bind to messenger (m)RNA, locate its protein-coding information, and translate the nucleotide triplets sequentially as codons into the corresponding sequence of amino acids, forming proteins. Non-coding mRNA features, such as 5' and 3' untranslated regions (UTRs), start sites or stop codons of different efficiency, stretches of slower or faster code and nascent polypeptide interactions can alter the translation rates transcript-wise. Most of the homeostatic and signal response pathways of the cells converge on individual mRNA control, as well as alter the global translation output. Among the multitude of approaches to study translational control, one of the most powerful is to infer the locations of translational complexes on mRNA based on the mRNA fragments protected by these complexes from endonucleolytic hydrolysis, or footprints. Translation complex profiling by high-throughput sequencing of the footprints allows to quantify the transcript-wise, as well as global, alterations of translation, and uncover the underlying control mechanisms by attributing footprint locations and sizes to different configurations of the translational complexes. The accuracy of all footprint profiling approaches critically depends on the fidelity of footprint generation and many methods have emerged to preserve certain or multiple configurations of the translational complexes, often in challenging biological material. In this review, a systematic summary of approaches to stabilize translational complexes on mRNA for footprinting is presented and major findings are discussed. Future directions of translation footprint profiling are outlined, focusing on the fidelity and accuracy of inference of the native in vivo translation complex distribution on mRNA.
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Affiliation(s)
- Nikolay E Shirokikh
- Division of Genome Sciences and Cancer, The John Curtin School of Medical Research, The Australian National University, Canberra, Australia
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6
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An Analysis of the Novel Fluorocycline TP-6076 Bound to Both the Ribosome and Multidrug Efflux Pump AdeJ from Acinetobacter baumannii. mBio 2021; 13:e0373221. [PMID: 35100868 PMCID: PMC8805024 DOI: 10.1128/mbio.03732-21] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Antibiotic resistance among bacterial pathogens continues to pose a serious global health threat. Multidrug-resistant (MDR) strains of the Gram-negative organism Acinetobacter baumannii utilize a number of resistance determinants to evade current antibiotics. One of the major resistance mechanisms employed by these pathogens is the use of multidrug efflux pumps. These pumps extrude xenobiotics directly out of bacterial cells, resulting in treatment failures when common antibiotics are administered. Here, the structure of the novel tetracycline antibiotic TP-6076, bound to both the Acinetobacter drug efflux pump AdeJ and the ribosome from Acinetobacter baumannii, using single-particle cryo-electron microscopy (cryo-EM), is elucidated. In this work, the structure of the AdeJ-TP-6076 complex is solved, and we show that AdeJ utilizes a network of hydrophobic interactions to recognize this fluorocycline. Concomitant with this, we elucidate three structures of TP-6076 bound to the A. baumannii ribosome and determine that its binding is stabilized largely by electrostatic interactions. We then compare the differences in binding modes between TP-6076 and the related tetracycline antibiotic eravacycline in both targets. These differences suggest that modifications to the tetracycline core may be able to alter AdeJ binding while maintaining interactions with the ribosome. Together, this work highlights how different mechanisms are used to stabilize the binding of tetracycline-based compounds to unique bacterial targets and provides guidance for the future clinical development of tetracycline antibiotics. IMPORTANCE Treatment of antibiotic-resistant organisms such as A. baumannii represents an ongoing issue for modern medicine. The multidrug efflux pump AdeJ serves as a major resistance determinant in A. baumannii through its action of extruding antibiotics from the cell. In this work, we use cryo-EM to show how AdeJ recognizes the experimental tetracycline antibiotic TP-6076 and prevents this drug from interacting with the A. baumannii ribosome. Since AdeJ and the ribosome use different binding modes to stabilize interactions with TP-6076, exploiting these differences may guide future drug development for combating antibiotic-resistant A. baumannii and potentially other strains of MDR bacteria.
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7
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Sathoff AE, Lewenza S, Samac DA. Plant defensin antibacterial mode of action against Pseudomonas species. BMC Microbiol 2020; 20:173. [PMID: 32560676 PMCID: PMC7304088 DOI: 10.1186/s12866-020-01852-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Accepted: 06/12/2020] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Though many plant defensins exhibit antibacterial activity, little is known about their antibacterial mode of action (MOA). Antimicrobial peptides with a characterized MOA induce the expression of multiple bacterial outer membrane modifications, which are required for resistance to these membrane-targeting peptides. Mini-Tn5-lux mutant strains of Pseudomonas aeruginosa with Tn insertions disrupting outer membrane protective modifications were assessed for sensitivity against plant defensin peptides. These transcriptional lux reporter strains were also evaluated for lux gene expression in response to sublethal plant defensin exposure. Also, a plant pathogen, Pseudomonas syringae pv. syringae was modified through transposon mutagenesis to create mutants that are resistant to in vitro MtDef4 treatments. RESULTS Plant defensins displayed specific and potent antibacterial activity against strains of P. aeruginosa. A defensin from Medicago truncatula, MtDef4, induced dose-dependent gene expression of the aminoarabinose modification of LPS and surface polycation spermidine production operons. The ability for MtDef4 to damage bacterial outer membranes was also verified visually through fluorescent microscopy. Another defensin from M. truncatula, MtDef5, failed to induce lux gene expression and limited outer membrane damage was detected with fluorescent microscopy. The transposon insertion site on MtDef4 resistant P. syringae pv. syringae mutants was sequenced, and modifications of ribosomal genes were identified to contribute to enhanced resistance to plant defensin treatments. CONCLUSIONS MtDef4 damages the outer membrane similar to polymyxin B, which stimulates antimicrobial peptide resistance mechanisms to plant defensins. MtDef5, appears to have a different antibacterial MOA. Additionally, the MtDef4 antibacterial mode of action may also involve inhibition of translation.
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Affiliation(s)
- Andrew E Sathoff
- Department of Plant Pathology, 1991 Upper Buford Circle, University of Minnesota, St. Paul, MN, 55108, USA. .,Department of Biology, Dakota State University, 820 N Washington Ave, Madison, SD, 57042, USA.
| | - Shawn Lewenza
- Department of Microbiology and Infectious Disease, 3330 Hospital Dr. N.W., University of Calgary, Calgary, AB, T2N 4Z6, Canada.,Faculty of Science and Technology, 1 University Dr., Athabasca University, Athabasca, AB, T9S 3A3, Canada
| | - Deborah A Samac
- Department of Plant Pathology, 1991 Upper Buford Circle, University of Minnesota, St. Paul, MN, 55108, USA.,USDA-ARS, Plant Science Research Unit, 1991 Upper Buford Circle, St. Paul, MN, 55108, USA
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8
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Wu Y, Ding X, Yang Y, Li Y, Qi Y, Hu F, Qin M, Liu Y, Sun L, Zhao Y. Optimization of biaryloxazolidinone as promising antibacterial agents against antibiotic-susceptible and antibiotic-resistant gram-positive bacteria. Eur J Med Chem 2020; 185:111781. [DOI: 10.1016/j.ejmech.2019.111781] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2019] [Revised: 06/01/2019] [Accepted: 10/09/2019] [Indexed: 12/22/2022]
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9
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Evangelisti E, Yunusov T, Shenhav L, Schornack S. N-acetyltransferase AAC(3)-I confers gentamicin resistance to Phytophthora palmivora and Phytophthora infestans. BMC Microbiol 2019; 19:265. [PMID: 31775609 PMCID: PMC6882347 DOI: 10.1186/s12866-019-1642-0] [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: 09/27/2019] [Accepted: 11/14/2019] [Indexed: 12/12/2022] Open
Abstract
Background Oomycetes are pathogens of mammals, fish, insects and plants, and the potato late blight agent Phytophthora infestans and the oil palm and cocoa infecting pathogen Phytophthora palmivora cause economically impacting diseases on a wide range of crop plants. Increasing genomic and transcriptomic resources and recent advances in oomycete biology demand new strategies for genetic modification of oomycetes. Most oomycete transformation procedures rely on geneticin-based selection of transgenic strains. Results We established N-acetyltransferase AAC(3)-I as a gentamicin-based selectable marker for oomycete transformation without interference with existing geneticin resistance. Strains carrying gentamicin resistance are fully infectious in plants. We further demonstrate the usefulness of this new antibiotic selection to super-transform well-characterized, already fluorescently-labelled P. palmivora strains and provide a comprehensive protocol for maintenance and zoospore electro-transformation of Phytophthora strains to aid in plant-pathogen research. Conclusions N-acetyltransferase AAC(3)-I is functional in Phytophthora oomycetes. In addition, the substrate specificity of the AAC(3)-I enzyme allows for re-transformation of geneticin-resistant strains. Our findings and resources widen the possibilities to study oomycete cell biology and plant-oomycete interactions.
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Affiliation(s)
| | - Temur Yunusov
- Sainsbury Laboratory Cambridge University (SLCU), Cambridge, UK
| | - Liron Shenhav
- Sainsbury Laboratory Cambridge University (SLCU), Cambridge, UK
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10
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Abstract
Many antibiotics available in the clinic today directly inhibit bacterial translation. Despite the past success of such drugs, their efficacy is diminishing with the spread of antibiotic resistance. Through the use of ribosomal modifications, ribosomal protection proteins, translation elongation factors and mistranslation, many pathogens are able to establish resistance to common therapeutics. However, current efforts in drug discovery are focused on overcoming these obstacles through the modification or discovery of new treatment options. Here, we provide an overview for common mechanisms of resistance to translation-targeting drugs and summarize several important breakthroughs in recent drug development.
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Affiliation(s)
- Anne Witzky
- 1 Department of Molecular Genetics, Ohio State University , Columbus, OH 43210 , USA.,2 Center for RNA Biology, Ohio State University , Columbus, OH 43210 , USA
| | - Rodney Tollerson
- 2 Center for RNA Biology, Ohio State University , Columbus, OH 43210 , USA.,3 Department of Microbiology, Ohio State University , Columbus, OH 43210 , USA
| | - Michael Ibba
- 2 Center for RNA Biology, Ohio State University , Columbus, OH 43210 , USA.,3 Department of Microbiology, Ohio State University , Columbus, OH 43210 , USA
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11
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Holfeld L, Knappe D, Hoffmann R. Proline-rich antimicrobial peptides show a long-lasting post-antibiotic effect on Enterobacteriaceae and Pseudomonas aeruginosa. J Antimicrob Chemother 2019; 73:933-941. [PMID: 29309652 DOI: 10.1093/jac/dkx482] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Accepted: 11/21/2017] [Indexed: 01/28/2023] Open
Abstract
Background Proline-rich antimicrobial peptides (PrAMPs) represent a promising class of potential therapeutics to treat multiresistant infections. They inhibit bacterial protein translation at the 70S ribosome by either blocking the peptide-exit tunnel (oncocin type) or trapping release factors (apidaecin type). Objectives Besides direct concentration-dependent antibacterial effects, the post-antibiotic effect (PAE) is the second most important criterion of antimicrobial pharmacodynamics to be determined in vitro. Here, PAEs of 10 PrAMPs and three antibiotics against three Escherichia coli strains, Klebsiella pneumoniae ATCC 10031 and Pseudomonas aeruginosa ATCC 27853 were studied after 1 h of exposure. Methods A robust high-throughput screening to determine PAEs was established, i.e. liquid handling by a 96-channel pipetting system and continuous incubation and absorbance measurement in a microplate reader. Results Prolonged PAEs (≥4 h) were detected for all peptides at their MIC values against all strains; PAEs were even >10 h for Api88, Api137, Bac7(1-60) and A3-APO. The PAEs increased further at 4 × MIC. Aminoglycosides gentamicin and kanamycin usually showed lower PAEs (≤4 h) at MIC, but PAEs increased to > 10 h at 4 × MIC. Bacteriostatic chloramphenicol exhibited the shortest PAEs (<4 h). Conclusions The PAEs of PrAMPs studied against Enterobacteriaceae and P. aeruginosa for the first time were typically 4-fold stronger than for conventional antibiotics. Together with their fast and irreversible uptake by bacteria, the observed prolonged PAE of PrAMPs helps to explain their high in vivo efficacy despite unfavourable pharmacokinetics.
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Affiliation(s)
- Luzia Holfeld
- Institute of Bioanalytical Chemistry, Faculty of Chemistry and Mineralogy, Universität Leipzig, Deutscher Platz 5, Leipzig, Germany.,Center for Biotechnology and Biomedicine, Universität Leipzig, Deutscher Platz 5, Leipzig, Germany
| | - Daniel Knappe
- Institute of Bioanalytical Chemistry, Faculty of Chemistry and Mineralogy, Universität Leipzig, Deutscher Platz 5, Leipzig, Germany.,Center for Biotechnology and Biomedicine, Universität Leipzig, Deutscher Platz 5, Leipzig, Germany
| | - Ralf Hoffmann
- Institute of Bioanalytical Chemistry, Faculty of Chemistry and Mineralogy, Universität Leipzig, Deutscher Platz 5, Leipzig, Germany.,Center for Biotechnology and Biomedicine, Universität Leipzig, Deutscher Platz 5, Leipzig, Germany
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12
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Disney MD, Velagapudi SP, Li Y, Costales MG, Childs-Disney JL. Identifying and validating small molecules interacting with RNA (SMIRNAs). Methods Enzymol 2019; 623:45-66. [PMID: 31239057 PMCID: PMC6628145 DOI: 10.1016/bs.mie.2019.04.027] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
High throughput sequencing has revolutionized our ability to identify aberrant RNA expression and mutations that cause or contribute to disease. These data can be used directly to design oligonucleotide-based modalities using Watson-Crick pairing to target unstructured regions in an RNA. A complementary, although more difficult, strategy to deactivate a malfunctioning RNA is to target highly structured regions with small molecules. Indeed, RNA structures are directly causative of disease. Herein, we discuss emerging strategies to design high affinity, selective, bioactive ligands targeting RNA, or small molecules interacting with RNA (SMIRNAs), and target validation and profiling methods. An experimental foundation is required for a lead identification strategy for RNA structures, constructed from a library-vs.-library screen that probes vast libraries of small molecules for binding RNA three dimensional folds. Dubbed 2-dimensional combinatorial screening (2DCS), the resulting data can be mined against transcriptomes or the composite of RNAs that are produced in an organism to define folded RNA structures that can be targeted. By applying SMIRNAs to cells and using target validation tools such as Chemical Cross-Linking and Isolation by Pull-down (Chem-CLIP) and Small Molecule Nucleic Acid Profiling by Cleavage Applied to RNA (RiboSNAP), all targets engaged in cells can be defined, along with rules for molecular recognition to affect RNA biology. This chapter will describe lessons learned in applying these approaches in vitro, in cells, and in pre-clinical animal models of disease, enabling SMIRNAs to capture opportunities in chemical biology.
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Affiliation(s)
- Matthew D Disney
- Department of Chemistry, The Scripps Research Institute, Jupiter, FL, United States.
| | | | - Yue Li
- Department of Chemistry, The Scripps Research Institute, Jupiter, FL, United States
| | - Matthew G Costales
- Department of Chemistry, The Scripps Research Institute, Jupiter, FL, United States
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13
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Waduge P, Sakakibara Y, Chow CS. Chemical probing for examining the structure of modified RNAs and ligand binding to RNA. Methods 2019; 156:110-120. [DOI: 10.1016/j.ymeth.2018.10.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 10/04/2018] [Accepted: 10/22/2018] [Indexed: 12/15/2022] Open
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14
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Li Y, Disney MD. Precise Small Molecule Degradation of a Noncoding RNA Identifies Cellular Binding Sites and Modulates an Oncogenic Phenotype. ACS Chem Biol 2018; 13:3065-3071. [PMID: 30375843 DOI: 10.1021/acschembio.8b00827] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Herein, we describe the precise cellular destruction of an oncogenic noncoding RNA with a small molecule-bleomycin A5 conjugate, affording reversal of phenotype and a facile method to map the cellular binding sites of a small molecule. In particular, bleomycin A5 was coupled to a small molecule that selectively binds the microRNA-96 hairpin precursor (pri-miR-96). By coupling of bleomycin A5's free amine to the RNA binder, its affinity for binding to pri-miR-96 is >100-fold stronger than to DNA and the compound selectively cleaves pri-miR-96 in triple negative breast cancer (TNBC) cells. Indeed, selective cleavage of pri-miR-96 enhanced expression of FOXO1 protein, a pro-apoptotic transcription factor that miR-96 silences, and triggered apoptosis in TNBC cells. No effects were observed in healthy breast epithelial cells. Thus, conjugation of a small molecule to bleomycin A5's free amine may provide programmable control over its cellular targets. Few approaches are available to define the binding sites of small molecules within cellular RNAs. Our targeted cleavage method provides such an approach that is straightforward to implement. That is, we determined experimentally the site cleaved within pri-miR-96 in vitro and in cells; these studies revealed that the site of cleavage is the precise site for which the small molecule cleaver was designed and in agreement with modeling. These studies demonstrate the potential of sequence-based design to provide bioactive compounds that precisely recognize and cleave RNA in cells.
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Affiliation(s)
- Yue Li
- The Department of Chemistry, The Scripps Research Institute, Jupiter, Florida 33458, United States
| | - Matthew D. Disney
- The Department of Chemistry, The Scripps Research Institute, Jupiter, Florida 33458, United States
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15
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Volkov IL, Johansson M. Single-Molecule Tracking Approaches to Protein Synthesis Kinetics in Living Cells. Biochemistry 2018; 58:7-14. [PMID: 30404437 DOI: 10.1021/acs.biochem.8b00917] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Decades of traditional biochemistry, structural approaches, and, more recently, single-molecule-based in vitro techniques have provided us with an astonishingly detailed understanding of the molecular mechanism of ribosome-catalyzed protein synthesis. However, in order to understand these details in the context of cell physiology and population biology, new techniques to probe the dynamics of molecular processes inside the cell are needed. Recent years' development in super-resolved fluorescence microscopy has revolutionized imaging of intracellular processes, and we now have the possibility to directly peek into the microcosm of biomolecules in their native environment. In this Perspective, we discuss how these methods are currently being applied and further developed to study the kinetics of protein synthesis directly inside living cells.
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Affiliation(s)
- Ivan L Volkov
- Department of Cell and Molecular Biology , Uppsala University , Uppsala 75124 , Sweden
| | - Magnus Johansson
- Department of Cell and Molecular Biology , Uppsala University , Uppsala 75124 , Sweden
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16
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A Massively Parallel Selection of Small Molecule-RNA Motif Binding Partners Informs Design of an Antiviral from Sequence. Chem 2018; 4:2384-2404. [PMID: 30719503 DOI: 10.1016/j.chempr.2018.08.003] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Many RNAs cause disease; however, RNA is rarely exploited as a small-molecule drug target. Our programmatic focus is to define privileged RNA motif small-molecule interactions to enable the rational design of compounds that modulate RNA biology starting from only sequence. We completed a massive, library-versus-library screen that probed over 50 million binding events between RNA motifs and small molecules. The resulting data provide a rich encyclopedia of small-molecule RNA recognition patterns, defining chemotypes and RNA motifs that confer selective, avid binding. The resulting interaction maps were mined against the entire viral genome of hepatitis C virus (HCV). A small molecule was identified that avidly bound RNA motifs present in the HCV 30 UTR and inhibited viral replication while having no effect on host cells. Collectively, this study represents the first whole-genome pattern recognition between small molecules and RNA folds.
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Haniff HS, Graves A, Disney MD. Selective Small Molecule Recognition of RNA Base Pairs. ACS COMBINATORIAL SCIENCE 2018; 20:482-491. [PMID: 29966095 PMCID: PMC6325646 DOI: 10.1021/acscombsci.8b00049] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Many types of RNAs exist in the human transcriptome, yet only the bacterial ribosome has been exploited as a small molecule drug target. Aside from rRNA, other cellular RNAs such as noncoding RNAs have primarily secondary structure and limited tertiary structure. Within these secondary structures of noncanonically paired and unpaired regions, more than 50% are base paired, with most efforts to target these structures focused on looped regions. A void exists in the availability of small molecules capable of targeting RNA base pairs. Using chemoinformatics, an RNA-focused library enriched for nitrogen-containing heterocycles was developed and tested for binding RNA base pairs, leading to the identification of six selective and previously unknown binders. While all binders were derivatives of benzimidazoles, those with expanded aromatic polycycles bound selectively to AU pairs, while those with flexible urea side chains bound selectively to GC pairs. Two of the three selective GC pair binders can distinguish between two different orientations, 5'GG/3'CC and 5'GC/3'CG pairs. Furthermore, all six molecules showed >50-fold selectivity for RNA over DNA. These studies provide foundational knowledge to better exploit RNA as targets for small molecule chemical probes or lead therapeutics by using modules that target RNA base pairs.
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Affiliation(s)
- Hafeez S Haniff
- Department of Chemistry , The Scripps Research Institute , Jupiter , Florida 33458 , United States
| | - Amanda Graves
- Department of Chemistry , The Scripps Research Institute , Jupiter , Florida 33458 , United States
| | - Matthew D Disney
- Department of Chemistry , The Scripps Research Institute , Jupiter , Florida 33458 , United States
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Louzoun Zada S, Green KD, Shrestha SK, Herzog IM, Garneau-Tsodikova S, Fridman M. Derivatives of Ribosome-Inhibiting Antibiotic Chloramphenicol Inhibit the Biosynthesis of Bacterial Cell Wall. ACS Infect Dis 2018; 4:1121-1129. [PMID: 29714997 DOI: 10.1021/acsinfecdis.8b00078] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Here, we describe the preparation and evaluation of α,β-unsaturated carbonyl derivatives of the bacterial translation inhibiting antibiotic chloramphenicol (CAM). Compared to the parent antibiotic, two compounds containing α,β-unsaturated ketones (1 and 4) displayed a broader spectrum of activity against a panel of Gram-positive pathogens with a minimum inhibitory concentration range of 2-32 μg/mL. Interestingly, unlike the parent CAM, these compounds do not inhibit bacterial translation. Microscopic evidence and metabolic labeling of a cell wall peptidoglycan suggested that compounds 1 and 4 caused extensive damage to the envelope of Staphylococcus aureus cells by inhibition of the early stage of cell wall peptidoglycan biosynthesis. Unlike the effect of membrane-disrupting antimicrobial cationic amphiphiles, these compounds did not rapidly permeabilize the bacterial membrane. Like the parent antibiotic CAM, compounds 1 and 4 had a bacteriostatic effect on S. aureus. Both compounds 1 and 4 were cytotoxic to immortalized nucleated mammalian cells; however, neither caused measurable membrane damage to mammalian red blood cells. These data suggest that the reported CAM-derived antimicrobial agents offer a new molecular scaffold for development of novel bacterial cell wall biosynthesis inhibiting antibiotics.
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Affiliation(s)
- Sivan Louzoun Zada
- Raymond and Beverly Sackler Faculty of Exact Sciences, School of Chemistry, Tel Aviv University, Tel Aviv, 6997801, Israel
| | - Keith D. Green
- Department of Pharmaceutical Sciences, University of Kentucky, Lexington, Kentucky 40536-0596, United States
| | - Sanjib K. Shrestha
- Department of Pharmaceutical Sciences, University of Kentucky, Lexington, Kentucky 40536-0596, United States
| | - Ido M. Herzog
- Raymond and Beverly Sackler Faculty of Exact Sciences, School of Chemistry, Tel Aviv University, Tel Aviv, 6997801, Israel
| | - Sylvie Garneau-Tsodikova
- Department of Pharmaceutical Sciences, University of Kentucky, Lexington, Kentucky 40536-0596, United States
| | - Micha Fridman
- Raymond and Beverly Sackler Faculty of Exact Sciences, School of Chemistry, Tel Aviv University, Tel Aviv, 6997801, Israel
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Velagapudi SP, Costales MG, Vummidi BR, Nakai Y, Angelbello AJ, Tran T, Haniff HS, Matsumoto Y, Wang ZF, Chatterjee AK, Childs-Disney JL, Disney MD. Approved Anti-cancer Drugs Target Oncogenic Non-coding RNAs. Cell Chem Biol 2018; 25:1086-1094.e7. [PMID: 30251629 DOI: 10.1016/j.chembiol.2018.05.015] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 04/03/2018] [Accepted: 05/18/2018] [Indexed: 12/14/2022]
Abstract
Potential RNA drug targets for small molecules are found throughout the human transcriptome, yet small molecules known to elicit a pharmacological response by directly targeting RNA are limited to antibacterials. Herein, we describe AbsorbArray, a small molecule microarray-based approach that allows for unmodified compounds, including FDA-approved drugs, to be probed for binding to RNA motif libraries in a massively parallel format. Several drug classes bind RNA including kinase and topoisomerase inhibitors. The latter avidly bound the motif found in the Dicer site of oncogenic microRNA (miR)-21 and inhibited its processing both in vitro and in cells. The most potent compound de-repressed a downstream protein target and inhibited a miR-21-mediated invasive phenotype. The compound's activity was ablated upon overexpression of pre-miR-21. Target validation via chemical crosslinking and isolation by pull-down showed direct engagement of pre-miR-21 by the small molecule in cells, demonstrating that RNAs should indeed be considered druggable.
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Affiliation(s)
- Sai Pradeep Velagapudi
- Department of Chemistry, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Matthew G Costales
- Department of Chemistry, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Balayeshwanth R Vummidi
- Department of Chemistry, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Yoshio Nakai
- Department of Chemistry, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Alicia J Angelbello
- Department of Chemistry, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Tuan Tran
- Department of Chemistry, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Hafeez S Haniff
- Department of Chemistry, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Yasumasa Matsumoto
- Department of Chemistry, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Zi Fu Wang
- Department of Chemistry, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Arnab K Chatterjee
- California Institute for Biomedical Research (CALIBR), 11119 North Torrey Pines Road, Suite 100, La Jolla, CA 92037, USA
| | - Jessica L Childs-Disney
- Department of Chemistry, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Matthew D Disney
- Department of Chemistry, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA.
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Tkachenko AG. Stress Responses of Bacterial Cells as Mechanism of Development of Antibiotic Tolerance (Review). APPL BIOCHEM MICRO+ 2018. [DOI: 10.1134/s0003683818020114] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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21
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von Loeffelholz O, Natchiar SK, Djabeur N, Myasnikov AG, Kratzat H, Ménétret JF, Hazemann I, Klaholz BP. Focused classification and refinement in high-resolution cryo-EM structural analysis of ribosome complexes. Curr Opin Struct Biol 2017; 46:140-148. [PMID: 28850874 DOI: 10.1016/j.sbi.2017.07.007] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Revised: 07/23/2017] [Accepted: 07/27/2017] [Indexed: 11/17/2022]
Abstract
Cryo electron microscopy (cryo-EM) historically has had a strong impact on the structural and mechanistic analysis of protein synthesis by the prokaryotic and eukaryotic ribosomes. Vice versa, studying ribosomes has helped moving forwards many methodological aspects in single particle cryo-EM, at the level of automated data collection and image processing including advanced techniques for particle sorting to address structural and compositional heterogeneity. Here we review some of the latest ribosome structures, where cryo-EM allowed gaining unprecedented insights based on 3D structure sorting with focused classification and refinement methods helping to reach local resolution levels better than 3Å. Such high-resolution features now enable the analysis of drug interactions with RNA and protein side-chains including even the visualization of chemical modifications of the ribosomal RNA. These advances represent a major breakthrough in structural biology and show the strong potential of cryo-EM beyond the ribosome field including for structure-based drug design.
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Affiliation(s)
- Ottilie von Loeffelholz
- Centre for Integrative Biology (CBI), Department of Integrated Structural Biology, IGBMC (Institute of Genetics and of Molecular and Cellular Biology), 1 rue Laurent Fries, Illkirch, France; Centre National de la Recherche Scientifique (CNRS) UMR 7104, Illkirch, France; Institut National de la Santé et de la Recherche Médicale (INSERM) U964, Illkirch, France; Université de Strasbourg, Strasbourg, France
| | - S Kundhavai Natchiar
- Centre for Integrative Biology (CBI), Department of Integrated Structural Biology, IGBMC (Institute of Genetics and of Molecular and Cellular Biology), 1 rue Laurent Fries, Illkirch, France; Centre National de la Recherche Scientifique (CNRS) UMR 7104, Illkirch, France; Institut National de la Santé et de la Recherche Médicale (INSERM) U964, Illkirch, France; Université de Strasbourg, Strasbourg, France
| | - Nadia Djabeur
- Centre for Integrative Biology (CBI), Department of Integrated Structural Biology, IGBMC (Institute of Genetics and of Molecular and Cellular Biology), 1 rue Laurent Fries, Illkirch, France; Centre National de la Recherche Scientifique (CNRS) UMR 7104, Illkirch, France; Institut National de la Santé et de la Recherche Médicale (INSERM) U964, Illkirch, France; Université de Strasbourg, Strasbourg, France
| | - Alexander G Myasnikov
- Centre for Integrative Biology (CBI), Department of Integrated Structural Biology, IGBMC (Institute of Genetics and of Molecular and Cellular Biology), 1 rue Laurent Fries, Illkirch, France; Centre National de la Recherche Scientifique (CNRS) UMR 7104, Illkirch, France; Institut National de la Santé et de la Recherche Médicale (INSERM) U964, Illkirch, France; Université de Strasbourg, Strasbourg, France
| | - Hanna Kratzat
- Centre for Integrative Biology (CBI), Department of Integrated Structural Biology, IGBMC (Institute of Genetics and of Molecular and Cellular Biology), 1 rue Laurent Fries, Illkirch, France; Centre National de la Recherche Scientifique (CNRS) UMR 7104, Illkirch, France; Institut National de la Santé et de la Recherche Médicale (INSERM) U964, Illkirch, France; Université de Strasbourg, Strasbourg, France
| | - Jean-François Ménétret
- Centre for Integrative Biology (CBI), Department of Integrated Structural Biology, IGBMC (Institute of Genetics and of Molecular and Cellular Biology), 1 rue Laurent Fries, Illkirch, France; Centre National de la Recherche Scientifique (CNRS) UMR 7104, Illkirch, France; Institut National de la Santé et de la Recherche Médicale (INSERM) U964, Illkirch, France; Université de Strasbourg, Strasbourg, France
| | - Isabelle Hazemann
- Centre for Integrative Biology (CBI), Department of Integrated Structural Biology, IGBMC (Institute of Genetics and of Molecular and Cellular Biology), 1 rue Laurent Fries, Illkirch, France; Centre National de la Recherche Scientifique (CNRS) UMR 7104, Illkirch, France; Institut National de la Santé et de la Recherche Médicale (INSERM) U964, Illkirch, France; Université de Strasbourg, Strasbourg, France
| | - Bruno P Klaholz
- Centre for Integrative Biology (CBI), Department of Integrated Structural Biology, IGBMC (Institute of Genetics and of Molecular and Cellular Biology), 1 rue Laurent Fries, Illkirch, France; Centre National de la Recherche Scientifique (CNRS) UMR 7104, Illkirch, France; Institut National de la Santé et de la Recherche Médicale (INSERM) U964, Illkirch, France; Université de Strasbourg, Strasbourg, France. mailto:
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Abstract
We postulate that the inhibition of growth and low rates of mortality of bacteria exposed to ribosome-binding antibiotics deemed bacteriostatic can be attributed almost uniquely to these drugs reducing the number of ribosomes contributing to protein synthesis, i.e., the number of effective ribosomes. We tested this hypothesis with Escherichia coli K-12 MG1655 and constructs that had been deleted for 1 to 6 of the 7 rRNA (rrn) operons. In the absence of antibiotics, constructs with fewer rrn operons have lower maximum growth rates and longer lag phases than those with more ribosomal operons. In the presence of the ribosome-binding “bacteriostatic” antibiotics tetracycline, chloramphenicol, and azithromycin, E. coli strains with 1 and 2 rrn operons are killed at a substantially higher rate than those with more rrn operons. This increase in the susceptibility of E. coli with fewer rrn operons to killing by ribosome-targeting bacteriostatic antibiotics is not reflected in their greater sensitivity to killing by the bactericidal antibiotic ciprofloxacin, which does not target ribosomes, but also to killing by gentamicin, which does. Finally, when such strains are exposed to these ribosome-targeting bacteriostatic antibiotics, the time before these bacteria start to grow again when the drugs are removed, referred to as the post-antibiotic effect (PAE), is markedly greater for constructs with fewer rrn operons than for those with more rrn operons. We interpret the results of these other experiments reported here as support for the hypothesis that the reduction in the effective number of ribosomes due to binding to these structures provides a sufficient explanation for the action of bacteriostatic antibiotics that target these structures. Chemotherapeutic agents, including antibiotics, have been used for more than a century; nevertheless, there are still major gaps in our understanding of how these drugs operate which limit future advances in antibacterial chemotherapy. Although the molecular mechanisms by which antibiotics bind to their target structures are largely known, fundamental questions about how these drugs actually kill and/or inhibit the replication of bacteria remain unanswered and subjects of controversy. We postulate that for the broad class of ribosome-binding bacteriostatic antibiotics, their reducing the number of active (functional) ribosomes per cell provides a sufficient explanation for the abatement of replication and the low rate of decline in densities of viable cells of bacteria exposed to these drugs. Using E. coli K-12 constructs with deletions of from one to six of the seven ribosome-RNA operons and the ribosome-binding bacteriostatic antibiotics tetracycline, chloramphenicol, and azithromycin, we tested this hypothesis. The results of our experiments are consistent with this “numbers game” hypothesis.
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Tabatabaei I, Ruf S, Bock R. A bifunctional aminoglycoside acetyltransferase/phosphotransferase conferring tobramycin resistance provides an efficient selectable marker for plastid transformation. PLANT MOLECULAR BIOLOGY 2017; 93:269-281. [PMID: 27858324 PMCID: PMC5306187 DOI: 10.1007/s11103-016-0560-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 11/10/2016] [Indexed: 05/22/2023]
Abstract
KEY MESSAGE A new selectable marker gene for stable transformation of the plastid genome was developed that is similarly efficient as the aadA, and produces no background of spontaneous resistance mutants. More than 25 years after its development for Chlamydomonas and tobacco, the transformation of the chloroplast genome still represents a challenging technology that is available only in a handful of species. The vast majority of chloroplast transformation experiments conducted thus far have relied on a single selectable marker gene, the spectinomycin resistance gene aadA. Although a few alternative markers have been reported, the aadA has remained unrivalled in efficiency and is, therefore, nearly exclusively used. The development of new marker genes for plastid transformation is of crucial importance to all efforts towards extending the species range of the technology as well as to those applications in basic research, biotechnology and synthetic biology that involve the multistep engineering of plastid genomes. Here, we have tested a bifunctional resistance gene for its suitability as a selectable marker for chloroplast transformation. The bacterial enzyme aminoglycoside acetyltransferase(6')-Ie/aminoglycoside phosphotransferase(2″)-Ia possesses an N-terminal acetyltransferase domain and a C-terminal phosphotransferase domain that can act synergistically and detoxify aminoglycoside antibiotics highly efficiently. We report that, in combination with selection for resistance to the aminoglycoside tobramycin, the aac(6')-Ie/aph(2″)-Ia gene represents an efficient marker for plastid transformation in that it produces similar numbers of transplastomic lines as the spectinomycin resistance gene aadA. Importantly, no spontaneous antibiotic resistance mutants appear under tobramycin selection.
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Affiliation(s)
- Iman Tabatabaei
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, 14476, Potsdam-Golm, Germany
| | - Stephanie Ruf
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, 14476, Potsdam-Golm, Germany
| | - Ralph Bock
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, 14476, Potsdam-Golm, Germany.
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Modeling the Overproduction of Ribosomes when Antibacterial Drugs Act on Cells. Biophys J 2017; 110:743-748. [PMID: 26840738 PMCID: PMC4744161 DOI: 10.1016/j.bpj.2015.12.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Revised: 12/12/2015] [Accepted: 12/15/2015] [Indexed: 02/04/2023] Open
Abstract
Bacteria that are subjected to ribosome-inhibiting antibiotic drugs show an interesting behavior: Although the drug slows down cell growth, it also paradoxically increases the cell’s concentration of ribosomes. We combine our earlier nonlinear model of the energy-biomass balance in undrugged Escherichia coli cells with Michaelis-Menten binding of drugs that inactivate ribosomes. Predictions are in good agreement with experiments on ribosomal concentrations and synthesis rates versus drug concentrations and growth rates. The model indicates that the added drug drives the cell to overproduce ribosomes, keeping roughly constant the level of ribosomes producing ribosomal proteins, an important quantity for cell growth. The model also predicts that ribosomal production rates should increase and then decrease with added drug. This model gives insights into the driving forces in cells and suggests new experiments.
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25
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Trans-translation is essential in the human pathogen Legionella pneumophila. Sci Rep 2016; 6:37935. [PMID: 27892503 PMCID: PMC5124942 DOI: 10.1038/srep37935] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Accepted: 11/02/2016] [Indexed: 11/09/2022] Open
Abstract
Trans-translation is a ubiquitous bacterial mechanism for ribosome rescue in the event of translation stalling. Although trans-translation is not essential in several bacterial species, it has been found essential for viability or virulence in a wide range of pathogens. We describe here that trans-translation is essential in the human pathogen Legionella pneumophila, the etiologic agent of Legionnaire's disease (LD), a severe form of nosocomial and community-acquired pneumonia. The ssrA gene coding for tmRNA, the key component of trans-translation, could not be deleted in L. pneumophila. To circumvent this and analyse the consequences of impaired trans-translation, we placed ssrA under the control of a chemical inducer. Phenotypes associated with the inhibition of ssrA expression include growth arrest in rich medium, hampered cell division, and hindered ability to infect eukaryotic cells (amoebae and human macrophages). LD is often associated with failure of antibiotic treatment and death (>10% of clinical cases). Decreasing tmRNA levels led to significantly higher sensitivity to ribosome-targeting antibiotics, including to erythromycin. We also detected a higher sensitivity to the transcription inhibitor rifampicin. Both antibiotics are recommended treatments for LD. Thus, interfering with trans-translation may not only halt the infection, but could also potentiate the recommended therapeutic treatments of LD.
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Structure-function insights reveal the human ribosome as a cancer target for antibiotics. Nat Commun 2016; 7:12856. [PMID: 27665925 PMCID: PMC5052680 DOI: 10.1038/ncomms12856] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Accepted: 08/04/2016] [Indexed: 01/25/2023] Open
Abstract
Many antibiotics in clinical use target the bacterial ribosome by interfering with the protein synthesis machinery. However, targeting the human ribosome in the case of protein synthesis deregulations such as in highly proliferating cancer cells has not been investigated at the molecular level up to now. Here we report the structure of the human 80S ribosome with a eukaryote-specific antibiotic and show its anti-proliferative effect on several cancer cell lines. The structure provides insights into the detailed interactions in a ligand-binding pocket of the human ribosome that are required for structure-assisted drug design. Furthermore, anti-proliferative dose response in leukaemic cells and interference with synthesis of c-myc and mcl-1 short-lived protein markers reveals specificity of a series of eukaryote-specific antibiotics towards cytosolic rather than mitochondrial ribosomes, uncovering the human ribosome as a promising cancer target. The ribosome of bacteria and other unicellular pathogens is a common target for antibiotic drugs. Here the authors determine a structure of the human ribosome bound to the translation inhibitor cycloheximide, and provide evidence that targeting the ribosome is a promising avenue for cancer therapy.
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27
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Grunenberg J, Licari G. Effective in silico prediction of new oxazolidinone antibiotics: force field simulations of the antibiotic-ribosome complex supervised by experiment and electronic structure methods. Beilstein J Org Chem 2016; 12:415-28. [PMID: 27340438 PMCID: PMC4902031 DOI: 10.3762/bjoc.12.45] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Accepted: 02/16/2016] [Indexed: 12/16/2022] Open
Abstract
We propose several new and promising antibacterial agents for the treatment of serious Gram-positive infections. Our predictions rely on force field simulations, supervised by first principle calculations and available experimental data. Different force fields were tested in order to reproduce linezolid's conformational space in terms of a) the isolated and b) the ribosomal bound state. In a first step, an all-atom model of the bacterial ribosome consisting of nearly 1600 atoms was constructed and evaluated. The conformational space of 30 different ribosomal/oxazolidinone complexes was scanned by stochastic methods, followed by an evaluation of their enthalpic penalties or rewards and the mechanical strengths of the relevant hydrogen bonds (relaxed force constants; compliance constants). The protocol was able to reproduce the experimentally known enantioselectivity favoring the S-enantiomer. In a second step, the experimentally known MIC values of eight linezolid analogues were used in order to crosscheck the robustness of our model. In a final step, this benchmarking led to the prediction of several new and promising lead compounds. Synthesis and biological evaluation of the new compounds are on the way.
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Affiliation(s)
- Jörg Grunenberg
- Institut für Organische Chemie, Hagenring30, TU-Braunschweig, 38106 Braunschweig, Germany
| | - Giuseppe Licari
- Institut für Organische Chemie, Hagenring30, TU-Braunschweig, 38106 Braunschweig, Germany; Physical Chemistry Department, Sciences II, University of Geneva , 30, Quai Ernest Ansermet, CH-1211 Geneva 4, Switzerland
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28
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Yang WY, Gao R, Southern M, Sarkar PS, Disney MD. Design of a bioactive small molecule that targets r(AUUCU) repeats in spinocerebellar ataxia 10. Nat Commun 2016; 7:11647. [PMID: 27248057 PMCID: PMC4895354 DOI: 10.1038/ncomms11647] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Accepted: 04/18/2016] [Indexed: 12/22/2022] Open
Abstract
RNA is an important target for chemical probes of function and lead therapeutics; however, it is difficult to target with small molecules. One approach to tackle this problem is to identify compounds that target RNA structures and utilize them to multivalently target RNA. Here we show that small molecules can be identified to selectively bind RNA base pairs by probing a library of RNA-focused small molecules. A small molecule that selectively binds AU base pairs informed design of a dimeric compound (2AU-2) that targets the pathogenic RNA, expanded r(AUUCU) repeats, that causes spinocerebellar ataxia type 10 (SCA10) in patient-derived cells. Indeed, 2AU-2 (50 nM) ameliorates various aspects of SCA10 pathology including improvement of mitochondrial dysfunction, reduced activation of caspase 3, and reduction of nuclear foci. These studies provide a first-in-class chemical probe to study SCA10 RNA toxicity and potentially define broadly applicable compounds targeting RNA AU base pairs in cells. Expanded RNA repeats in non-coding region of a gene represent a hallmark of several diseases. Here, the authors identify two small molecules that selectively bind AU repeats and use them to design a compound that targets the pathogenic RNA associated with spinocerebellar ataxia type 10.
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Affiliation(s)
- Wang-Yong Yang
- Departments of Chemistry and Neuroscience, The Scripps Research Institute, Scripps Florida, Jupiter, Florida 33458, USA
| | - Rui Gao
- Mitchell Center for Neurodegenerative Disorders, Department of Neurology, Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, Texas 77555, USA
| | - Mark Southern
- Informatics Core, The Scripps Research Institute, Scripps Florida, Jupiter, Florida 33458, USA
| | - Partha S Sarkar
- Mitchell Center for Neurodegenerative Disorders, Department of Neurology, Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, Texas 77555, USA
| | - Matthew D Disney
- Departments of Chemistry and Neuroscience, The Scripps Research Institute, Scripps Florida, Jupiter, Florida 33458, USA
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Müller C, Sokol L, Vesper O, Sauert M, Moll I. Insights into the Stress Response Triggered by Kasugamycin in Escherichia coli. Antibiotics (Basel) 2016; 5:E19. [PMID: 27258317 PMCID: PMC4929434 DOI: 10.3390/antibiotics5020019] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 05/19/2016] [Accepted: 05/23/2016] [Indexed: 01/06/2023] Open
Abstract
The bacteriostatic aminoglycoside antibiotic kasugamycin inhibits protein synthesis at an initial step without affecting translation elongation. It binds to the mRNA track of the ribosome and prevents formation of the translation initiation complex on canonical mRNAs. In contrast, translation of leaderless mRNAs continues in the presence of the drug in vivo. Previously, we have shown that kasugamycin treatment in E. coli stimulates the formation of protein-depleted ribosomes that are selective for leaderless mRNAs. Here, we provide evidence that prolonged kasugamycin treatment leads to selective synthesis of specific proteins. Our studies indicate that leaderless and short-leadered mRNAs are generated by different molecular mechanisms including alternative transcription and RNA processing. Moreover, we provide evidence for ribosome heterogeneity in response to kasugamycin treatment by alteration of the modification status of the stalk proteins bL7/L12.
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Affiliation(s)
- Christian Müller
- Max F. Perutz Laboratories, Center for Molecular Biology, Department of Microbiology, Immunobiology and Genetics, University of Vienna, Vienna Biocenter (VBC), Dr. Bohr-Gasse 9/4, A-1030 Vienna, Austria.
| | - Lena Sokol
- Max F. Perutz Laboratories, Center for Molecular Biology, Department of Microbiology, Immunobiology and Genetics, University of Vienna, Vienna Biocenter (VBC), Dr. Bohr-Gasse 9/4, A-1030 Vienna, Austria.
| | - Oliver Vesper
- Max F. Perutz Laboratories, Center for Molecular Biology, Department of Microbiology, Immunobiology and Genetics, University of Vienna, Vienna Biocenter (VBC), Dr. Bohr-Gasse 9/4, A-1030 Vienna, Austria.
| | - Martina Sauert
- Max F. Perutz Laboratories, Center for Molecular Biology, Department of Microbiology, Immunobiology and Genetics, University of Vienna, Vienna Biocenter (VBC), Dr. Bohr-Gasse 9/4, A-1030 Vienna, Austria.
| | - Isabella Moll
- Max F. Perutz Laboratories, Center for Molecular Biology, Department of Microbiology, Immunobiology and Genetics, University of Vienna, Vienna Biocenter (VBC), Dr. Bohr-Gasse 9/4, A-1030 Vienna, Austria.
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Nikolay R, Schmidt S, Schlömer R, Deuerling E, Nierhaus KH. Ribosome Assembly as Antimicrobial Target. Antibiotics (Basel) 2016; 5:E18. [PMID: 27240412 PMCID: PMC4929433 DOI: 10.3390/antibiotics5020018] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 05/02/2016] [Accepted: 05/16/2016] [Indexed: 12/19/2022] Open
Abstract
Many antibiotics target the ribosome and interfere with its translation cycle. Since translation is the source of all cellular proteins including ribosomal proteins, protein synthesis and ribosome assembly are interdependent. As a consequence, the activity of translation inhibitors might indirectly cause defective ribosome assembly. Due to the difficulty in distinguishing between direct and indirect effects, and because assembly is probably a target in its own right, concepts are needed to identify small molecules that directly inhibit ribosome assembly. Here, we summarize the basic facts of ribosome targeting antibiotics. Furthermore, we present an in vivo screening strategy that focuses on ribosome assembly by a direct fluorescence based read-out that aims to identify and characterize small molecules acting as primary assembly inhibitors.
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Affiliation(s)
- Rainer Nikolay
- Institut für Medizinische Physik und Biophysik, Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany.
| | - Sabine Schmidt
- Molecular Microbiology, University of Konstanz, Konstanz 78457, Germany.
| | - Renate Schlömer
- Molecular Microbiology, University of Konstanz, Konstanz 78457, Germany.
| | - Elke Deuerling
- Molecular Microbiology, University of Konstanz, Konstanz 78457, Germany.
| | - Knud H Nierhaus
- Institut für Medizinische Physik und Biophysik, Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany.
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Glassford I, Teijaro CN, Daher SS, Weil A, Small MC, Redhu SK, Colussi DJ, Jacobson MA, Childers WE, Buttaro B, Nicholson AW, MacKerell AD, Cooperman BS, Andrade RB. Ribosome-Templated Azide-Alkyne Cycloadditions: Synthesis of Potent Macrolide Antibiotics by In Situ Click Chemistry. J Am Chem Soc 2016; 138:3136-44. [PMID: 26878192 PMCID: PMC4785600 DOI: 10.1021/jacs.5b13008] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Over half of all antibiotics target the bacterial ribosome-nature's complex, 2.5 MDa nanomachine responsible for decoding mRNA and synthesizing proteins. Macrolide antibiotics, exemplified by erythromycin, bind the 50S subunit with nM affinity and inhibit protein synthesis by blocking the passage of nascent oligopeptides. Solithromycin (1), a third-generation semisynthetic macrolide discovered by combinatorial copper-catalyzed click chemistry, was synthesized in situ by incubating either E. coli 70S ribosomes or 50S subunits with macrolide-functionalized azide 2 and 3-ethynylaniline (3) precursors. The ribosome-templated in situ click method was expanded from a binary reaction (i.e., one azide and one alkyne) to a six-component reaction (i.e., azide 2 and five alkynes) and ultimately to a 16-component reaction (i.e., azide 2 and 15 alkynes). The extent of triazole formation correlated with ribosome affinity for the anti (1,4)-regioisomers as revealed by measured Kd values. Computational analysis using the site-identification by ligand competitive saturation (SILCS) approach indicated that the relative affinity of the ligands was associated with the alteration of macrolactone+desosamine-ribosome interactions caused by the different alkynes. Protein synthesis inhibition experiments confirmed the mechanism of action. Evaluation of the minimal inhibitory concentrations (MIC) quantified the potency of the in situ click products and demonstrated the efficacy of this method in the triaging and prioritization of potent antibiotics that target the bacterial ribosome. Cell viability assays in human fibroblasts confirmed 2 and four analogues with therapeutic indices for bactericidal activity over in vitro mammalian cytotoxicity as essentially identical to solithromycin (1).
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Affiliation(s)
- Ian Glassford
- Department of Chemistry, Temple University, Philadelphia, PA 19122
| | | | - Samer S. Daher
- Department of Chemistry, Temple University, Philadelphia, PA 19122
| | - Amy Weil
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104
| | - Meagan C. Small
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, MD 21201
| | - Shiv K. Redhu
- Department of Biology, Temple University, Philadelphia, PA 19122
| | - Dennis J. Colussi
- Moulder Center for Drug Discovery Research, Temple University School of Pharmacy, Philadelphia, Pennsylvania, 19140, United States
| | - Marlene A. Jacobson
- Moulder Center for Drug Discovery Research, Temple University School of Pharmacy, Philadelphia, Pennsylvania, 19140, United States
| | - Wayne E. Childers
- Moulder Center for Drug Discovery Research, Temple University School of Pharmacy, Philadelphia, Pennsylvania, 19140, United States
| | - Bettina Buttaro
- Department of Microbiology and Immunology, Temple University School of Medicine, Philadelphia, PA 19140
| | | | - Alexander D. MacKerell
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, MD 21201
| | - Barry S. Cooperman
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104
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Bonventre JA, Zielke RA, Korotkov KV, Sikora AE. Targeting an Essential GTPase Obg for the Development of Broad-Spectrum Antibiotics. PLoS One 2016; 11:e0148222. [PMID: 26848972 PMCID: PMC4743925 DOI: 10.1371/journal.pone.0148222] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Accepted: 01/14/2016] [Indexed: 11/19/2022] Open
Abstract
A promising new drug target for the development of novel broad-spectrum antibiotics is the highly conserved small GTPase Obg (YhbZ, CgtA), a protein essential for the survival of all bacteria including Neisseria gonorrhoeae (GC). GC is the agent of gonorrhea, a prevalent sexually transmitted disease resulting in serious consequences on reproductive and neonatal health. A preventive anti-gonorrhea vaccine does not exist, and options for effective antibiotic treatments are increasingly limited. To address the dire need for alternative antimicrobial strategies, we have designed and optimized a 384-well GTPase assay to identify inhibitors of Obg using as a model Obg protein from GC, ObgGC. The assay was validated with a pilot screen of 40,000 compounds and achieved an average Z’ value of 0.58 ± 0.02, which suggests a robust assay amenable to high-throughput screening. We developed secondary assessments for identified lead compounds that utilize the interaction between ObgGC and fluorescent guanine nucleotide analogs, mant-GTP and mant-GDP, and an ObgGC variant with multiple alterations in the G-domains that prevent nucleotide binding. To evaluate the broad-spectrum potential of ObgGC inhibitors, Obg proteins of Klebsiella pneumoniae and methicillin-resistant Staphylococcus aureus were assessed using the colorimetric and fluorescence-based activity assays. These approaches can be useful in identifying broad-spectrum Obg inhibitors and advancing the therapeutic battle against multidrug resistant bacteria.
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Affiliation(s)
- Josephine A. Bonventre
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Corvallis, OR, 97330, United States of America
| | - Ryszard A. Zielke
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Corvallis, OR, 97330, United States of America
| | - Konstantin V. Korotkov
- Department of Molecular and Cellular Biochemistry, and Center for Structural Biology, University of Kentucky, Lexington, KY, 40536, United States of America
| | - Aleksandra E. Sikora
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Corvallis, OR, 97330, United States of America
- * E-mail:
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Zielke RA, Wierzbicki IH, Baarda BI, Sikora AE. The Neisseria gonorrhoeae Obg protein is an essential ribosome-associated GTPase and a potential drug target. BMC Microbiol 2015; 15:129. [PMID: 26122105 PMCID: PMC4487204 DOI: 10.1186/s12866-015-0453-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Accepted: 05/28/2015] [Indexed: 11/10/2022] Open
Abstract
Background Neisseria gonorrhoeae (GC) is a Gram-negative pathogen that most commonly infects mucosal surfaces, causing sexually transmitted urethritis in men and endocervicitis in women. Serious complications associated with these infections are frequent and include pelvic inflammatory disease, ectopic pregnancy, and infertility. The incidence of gonorrhea cases remains high globally while antibiotic treatment options, the sole counter measures against gonorrhea, are declining due to the remarkable ability of GC to acquire resistance. Evaluating of potential drug targets is essential to provide opportunities for developing antimicrobials with new mechanisms of action. We propose the GC Obg protein, belonging to the Obg/CgtA GTPase subfamily, as a potential target for the development of therapeutic interventions against gonorrhea, and in this study perform its initial functional and biochemical characterization. Results We report that NGO1990 encodes Obg protein, which is an essential factor for GC viability, associates predominantly with the large 50S ribosomal subunit, and is stably expressed under conditions relevant to infection of the human host. The anti-Obg antisera cross-reacts with a panel of contemporary GC clinical isolates, demonstrating the ubiquitous nature of Obg. The cellular levels of Obg reach a maximum in the early logarithmic phase and remain constant throughout bacterial growth. The in vitro binding and hydrolysis of the fluorescent guanine nucleotide analogs mant-GTP and mant-GDP by recombinant wild type and T192AT193A mutated variants of Obg are also assessed. Conclusions Characterization of the GC Obg at the molecular and functional levels presented herein may facilitate the future targeting of this protein with small molecule inhibitors and the evaluation of identified lead compounds for bactericidal activity against GC and other drug-resistant bacteria. Electronic supplementary material The online version of this article (doi:10.1186/s12866-015-0453-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Ryszard A Zielke
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, 433 Weniger Hall, 103 SW Memorial Pl, Corvallis, OR, 97330, USA.
| | - Igor H Wierzbicki
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, 433 Weniger Hall, 103 SW Memorial Pl, Corvallis, OR, 97330, USA.
| | - Benjamin I Baarda
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, 433 Weniger Hall, 103 SW Memorial Pl, Corvallis, OR, 97330, USA.
| | - Aleksandra E Sikora
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, 433 Weniger Hall, 103 SW Memorial Pl, Corvallis, OR, 97330, USA.
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Ramos-Tomillero I, Paradís-Bas M, de Pinho Ribeiro Moreira I, Bofill JM, Nicolás E, Albericio F. Formylation of electron-rich aromatic rings mediated by dichloromethyl methyl ether and TiCl4: scope and limitations. Molecules 2015; 20:5409-22. [PMID: 25822080 PMCID: PMC6272369 DOI: 10.3390/molecules20045409] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Revised: 03/08/2015] [Accepted: 03/12/2015] [Indexed: 12/11/2022] Open
Abstract
Here the aromatic formylation mediated by TiCl4 and dichloromethyl methyl ether previously described by our group has been explored for a wide range of aromatic rings, including phenols, methoxy- and methylbenzenes, as an excellent way to produce aromatic aldehydes. Here we determine that the regioselectivity of this process is highly promoted by the coordination between the atoms present in the aromatic moiety and those in the metal core.
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Affiliation(s)
- Iván Ramos-Tomillero
- Institute for Research in Biomedicine (IRB Barcelona), Barcelona 08028, Spain.
- Deparment of Organic Chemistry, University of Barcelona, Barcelona 08028, Spain.
| | - Marta Paradís-Bas
- Institute for Research in Biomedicine (IRB Barcelona), Barcelona 08028, Spain.
- Deparment of Organic Chemistry, University of Barcelona, Barcelona 08028, Spain.
| | - Ibério de Pinho Ribeiro Moreira
- Department of Physical Chemistry, University of Barcelona, Barcelona 08028, Spain.
- Institut de Química Teòrica i Computacional (IQTCUB), University of Barcelona, Barcelona 08028, Spain.
| | - Josep María Bofill
- Deparment of Organic Chemistry, University of Barcelona, Barcelona 08028, Spain.
- Institut de Química Teòrica i Computacional (IQTCUB), University of Barcelona, Barcelona 08028, Spain.
| | - Ernesto Nicolás
- Deparment of Organic Chemistry, University of Barcelona, Barcelona 08028, Spain.
- Institut de Biomedicina (IBUB), University of Barcelona, Barcelona 08028, Spain.
| | - Fernando Albericio
- Institute for Research in Biomedicine (IRB Barcelona), Barcelona 08028, Spain.
- Deparment of Organic Chemistry, University of Barcelona, Barcelona 08028, Spain.
- CIBER-BBN, Barcelona 08028, Spain.
- School of Chemistry, University of KwaZulu-Natal, Durban 4000, South Africa.
- School of Chemistry, Yachay Tech, Yachay City of Knowledge, Urcuqui 100119, Ecuador.
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Matsumura S, Ito T, Tanaka T, Furuta H, Ikawa Y. Modulation of group I ribozyme activity by cationic porphyrins. BIOLOGY 2015; 4:251-63. [PMID: 25811638 PMCID: PMC4498298 DOI: 10.3390/biology4020251] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Accepted: 03/03/2015] [Indexed: 11/16/2022]
Abstract
The effects of cationic porphyrins on the catalytic activities of four group I ribozymes were investigated. A cationic porphyrin possessing four pyridinium moieties (pPyP) inhibited two group IC3 ribozymes (Syn Rz and Azo Rz) and a group IC1 ribozyme (Tet Rz). In the case of a group IA2 ribozyme (Td Rz), however, pPyP served not only as an inhibitor but also as an activator, and the effects of pPyP were dependent on its concentration. To analyze the structural and electronic factors determining the effects of pPyP on group I ribozymes, three cationic porphyrins (pPyNCP, pPyF4P, and TMPyP) were also examined. As interactions between small organic molecules and nucleic acids are attractive and important issues in biochemistry and biotechnology, this study contributes to the development of porphyrin-based molecules that can modulate functions of structured RNA molecules.
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Affiliation(s)
- Shigeyoshi Matsumura
- Department of Chemistry, Graduate School of Science and Engineering, University of Toyama, Gofuku 3190, Toyama 930-8555, Japan.
| | - Tatsunobu Ito
- Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University, Moto-oka 744, Nishi-ku, Fukuoka 819-0395, Japan.
| | - Takahiro Tanaka
- Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University, Moto-oka 744, Nishi-ku, Fukuoka 819-0395, Japan.
| | - Hiroyuki Furuta
- Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University, Moto-oka 744, Nishi-ku, Fukuoka 819-0395, Japan.
- Center for Molecular Systems, Kyushu University, Moto-oka 744, Nishi-ku, Fukuoka 819-0395, Japan.
| | - Yoshiya Ikawa
- Department of Chemistry, Graduate School of Science and Engineering, University of Toyama, Gofuku 3190, Toyama 930-8555, Japan.
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36
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Abstract
The proteome of cells is synthesized by ribosomes, complex ribonucleoproteins that in eukaryotes contain 79-80 proteins and four ribosomal RNAs (rRNAs) more than 5,400 nucleotides long. How these molecules assemble together and how their assembly is regulated in concert with the growth and proliferation of cells remain important unanswered questions. Here, we review recently emerging principles to understand how eukaryotic ribosomal proteins drive ribosome assembly in vivo. Most ribosomal proteins assemble with rRNA cotranscriptionally; their association with nascent particles is strengthened as assembly proceeds. Each subunit is assembled hierarchically by sequential stabilization of their subdomains. The active sites of both subunits are constructed last, perhaps to prevent premature engagement of immature ribosomes with active subunits. Late-assembly intermediates undergo quality-control checks for proper function. Mutations in ribosomal proteins that affect mostly late steps lead to ribosomopathies, diseases that include a spectrum of cell type-specific disorders that often transition from hypoproliferative to hyperproliferative growth.
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Affiliation(s)
- Jesus de la Cruz
- Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocio/CSIC/Universidad de Sevilla, E-41013 Sevilla, Spain
- Departamento de Genetica, Universidad de Sevilla, E-41013 Sevilla, Spain
| | - Katrin Karbstein
- Department of Cancer Biology, The Scripps Research Institute, Jupiter, Florida 33458
| | - John L Woolford
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213
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Stokes JM, Davis JH, Mangat CS, Williamson JR, Brown ED. Discovery of a small molecule that inhibits bacterial ribosome biogenesis. eLife 2014; 3:e03574. [PMID: 25233066 PMCID: PMC4371806 DOI: 10.7554/elife.03574] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Accepted: 09/17/2014] [Indexed: 11/29/2022] Open
Abstract
While small molecule inhibitors of the bacterial ribosome have been instrumental in
understanding protein translation, no such probes exist to study ribosome biogenesis.
We screened a diverse chemical collection that included previously approved drugs for
compounds that induced cold sensitive growth inhibition in the model bacterium
Escherichia coli. Among the most cold sensitive was lamotrigine,
an anticonvulsant drug. Lamotrigine treatment resulted in the rapid accumulation of
immature 30S and 50S ribosomal subunits at 15°C. Importantly, this was not the result
of translation inhibition, as lamotrigine was incapable of perturbing protein
synthesis in vivo or in vitro. Spontaneous suppressor mutations blocking lamotrigine
activity mapped solely to the poorly characterized domain II of translation
initiation factor IF2 and prevented the binding of lamotrigine to IF2 in vitro. This
work establishes lamotrigine as a widely available chemical probe of bacterial
ribosome biogenesis and suggests a role for E. coli IF2 in ribosome
assembly. DOI:http://dx.doi.org/10.7554/eLife.03574.001 Inside cells, molecular machines called ribosomes make proteins from instructions
that are provided by genes. The ribosomes themselves are made up of about 50 proteins
and three RNA molecules that need to be assembled like a 3-D jigsaw. In bacteria, a
group of proteins called ribosome biogenesis factors help to assemble these pieces
correctly. To study how a biological process works, scientists often look at what happens when a
component is missing or not working properly. However, this approach cannot be used
to study how ribosomes are made because stopping protein production entirely will
kill the cell. Another approach is to use chemicals to temporarily stop or slow down
a biological process, but researchers are yet to find a chemical that can do this for
ribosome assembly. To address this problem, Stokes et al. ‘screened’ 30,000 chemicals in an effort to
find one or more that could affect ribosome assembly in bacteria. The screen revealed
that a drug called lamotrigine—which is used to treat epilepsy and other conditions
in humans—could stop the assembly of ribosomes, but did not affect the production of
proteins by completed ribosomes. The experiments also suggest that initiation factor 2, a protein that is involved in
the production of other proteins, may also have a role in ribosome assembly. Another
recent study found that the equivalent of initiation factor 2 in yeast acts as a
quality control checkpoint during ribosome assembly, so the bacterial version may
also perform a similar role. It is also be possible that lamotrigine might be used to help develop a novel
mechanistic class of antibiotics. DOI:http://dx.doi.org/10.7554/eLife.03574.002
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Affiliation(s)
- Jonathan M Stokes
- Michael G DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Canada
| | - Joseph H Davis
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, United States
| | - Chand S Mangat
- Michael G DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Canada
| | - James R Williamson
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, United States
| | - Eric D Brown
- Michael G DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Canada
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Martins R, Queiroz J, Sousa F. Ribonucleic acid purification. J Chromatogr A 2014; 1355:1-14. [DOI: 10.1016/j.chroma.2014.05.075] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2014] [Revised: 05/23/2014] [Accepted: 05/27/2014] [Indexed: 11/24/2022]
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Spatially segregated transcription and translation in cells of the endomembrane-containing bacterium Gemmata obscuriglobus. Proc Natl Acad Sci U S A 2014; 111:11067-72. [PMID: 25024214 DOI: 10.1073/pnas.1409187111] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The dogma of coupled transcription and translation in bacteria has been challenged by recent reports of spatial segregation of these processes within the relatively simple cellular organization of the model organisms Escherichia coli and Bacillus subtilis. The bacterial species Gemmata obscuriglobus possesses an extensive endomembrane system. The membranes generate a very convoluted intracellular architecture in which some of the cell's ribosomes appear to have less direct access to the cell's nucleoid(s) than others. This observation prompted us to test the hypothesis that a substantial proportion of G. obscuriglobus translation may be spatially segregated from transcription. Using immunofluorescence and immunoelectron microscopy, we showed that translating ribosomes are localized throughout the cell, with a quantitatively greater proportion found in regions distal to nucleoid(s). Our results extend information about the phylogenetic and morphological diversity of bacteria in which the spatial organization of transcription and translation has been studied. These findings also suggest that endomembranes may provide an obstacle to colocated transcription and translation, a role for endomembranes that has not been reported previously for a prokaryotic organism. Our studies of G. obscuriglobus may provide a useful background for consideration of the evolutionary development of eukaryotic cellular complexity and how it led to decoupled processes of gene expression in eukaryotes.
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40
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Nikolay R, Schloemer R, Schmidt S, Mueller S, Heubach A, Deuerling E. Validation of a fluorescence-based screening concept to identify ribosome assembly defects in Escherichia coli. Nucleic Acids Res 2014; 42:e100. [PMID: 24792169 PMCID: PMC4081057 DOI: 10.1093/nar/gku381] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Revised: 04/15/2014] [Accepted: 04/17/2014] [Indexed: 11/27/2022] Open
Abstract
While the structure of mature ribosomes is analyzed in atomic detail considerably less is known about their assembly process in living cells. This is mainly due to technical and conceptual hurdles. To analyze ribosome assembly in vivo, we designed and engineered an Escherichiacoli strain--using chromosomal gene knock-in techniques--that harbors large and small ribosomal subunits labeled with the fluorescent proteins EGFP and mCherry, respectively. A thorough characterization of this reporter strain revealed that its growth properties and translation apparatus were wild-type like. Alterations in the ratio of EGFP over mCherry fluorescence are supposed to indicate ribosome assembly defects. To provide proof of principle, subunit specific assembly defects were provoked and could be identified by both manual and fully automated fluorometric in vivo assays. This is to our knowledge the first methodology that directly detects ribosome assembly defects in vivo in a high-throughput compatible format. Screening of knock-out collections and small molecule libraries will allow identification of new ribosome assembly factors and possible inhibitors.
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Affiliation(s)
- Rainer Nikolay
- Molecular Microbiology, University of Konstanz, Konstanz 78457, Germany
| | - Renate Schloemer
- Molecular Microbiology, University of Konstanz, Konstanz 78457, Germany
| | - Sabine Schmidt
- Molecular Microbiology, University of Konstanz, Konstanz 78457, Germany
| | - Silke Mueller
- Screening Center Konstanz, University of Konstanz, Konstanz 78457, Germany
| | - Anja Heubach
- Molecular Microbiology, University of Konstanz, Konstanz 78457, Germany
| | - Elke Deuerling
- Molecular Microbiology, University of Konstanz, Konstanz 78457, Germany
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Abstract
SIGNIFICANCE The mitochondrial genetic system is responsible for the production of a few core-subunits of the respiratory chain and ATP synthase, the membrane protein complexes driving oxidative phosphorylation (OXPHOS). Efficiency and accuracy of mitochondrial protein synthesis determines how efficiently new OXPHOS complexes can be made. RECENT ADVANCES The system responsible for expression of the mitochondrial-encoded subunits developed from that of the bacterial ancestor of mitochondria. Importantly, many aspects of genome organization, transcription, and translation have diverged during evolution. Recent research has provided new insights into the architecture, regulation, and organelle-specific features of mitochondrial translation. Mitochondrial ribosomes contain a number of proteins absent from prokaryotic ribosomes, implying that in mitochondria, ribosomes were tailored to fit the requirements of the organelle. In addition, mitochondrial gene expression is regulated post-transcriptionally by a number of mRNA-specific translational activators. At least in yeast, these factors can regulate translation in respect to OXPHOS complex assembly to adjust the level of newly synthesized proteins to amounts that can be successfully assembled into respiratory chain complexes. CRITICAL ISSUES Mitochondrial gene expression is determining aging in eukaryotes, and a number of recent reports indicate that efficiency of translation directly influences this process. FUTURE DIRECTIONS Here we will summarize recent advances in our understanding of mitochondrial protein synthesis by comparing the knowledge acquired in the systems most commonly used to study mitochondrial biogenesis. However, many steps have not been understood mechanistically. Innovative biochemical and genetic approaches have to be elaborated to shed light on these important processes.
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Affiliation(s)
- Kirsten Kehrein
- 1 Center for Biomembrane Research, Department of Biochemistry and Biophysics, Stockholm University , Stockholm, Sweden
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42
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Berkov-Zrihen Y, Green KD, Labby KJ, Feldman M, Garneau-Tsodikova S, Fridman M. Synthesis and evaluation of hetero- and homodimers of ribosome-targeting antibiotics: antimicrobial activity, in vitro inhibition of translation, and drug resistance. J Med Chem 2013; 56:5613-25. [PMID: 23786357 PMCID: PMC3823688 DOI: 10.1021/jm400707f] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In this study, we describe the synthesis of a full set of homo- and heterodimers of three intact structures of different ribosome-targeting antibiotics: tobramycin, clindamycin, and chloramphenicol. Several aspects of the biological activity of the dimeric structures were evaluated including antimicrobial activity, inhibition of in vitro bacterial protein translation, and the effect of dimerization on the action of several bacterial resistance mechanisms that deactivate tobramycin and chloramphenicol. This study demonstrates that covalently linking two identical or different ribosome-targeting antibiotics may lead to (i) a broader spectrum of antimicrobial activity, (ii) improved inhibition of bacterial translation properties compared to that of the parent antibiotics, and (iii) reduction in the efficacy of some drug-modifying enzymes that confer high levels of resistance to the parent antibiotics from which the dimers were derived.
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Affiliation(s)
| | - Keith D. Green
- Department of Medicinal Chemistry and the Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, 48109, United States
| | - Kristin J. Labby
- Department of Medicinal Chemistry and the Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, 48109, United States
| | - Mark Feldman
- School of Chemistry, Tel Aviv University, Tel Aviv, 6997801, Israel
| | - Sylvie Garneau-Tsodikova
- Department of Medicinal Chemistry and the Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, 48109, United States
| | - Micha Fridman
- School of Chemistry, Tel Aviv University, Tel Aviv, 6997801, Israel
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43
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Wang S, Zhou S, Liu W. Opportunities and challenges from current investigations into the biosynthetic logic of nosiheptide-represented thiopeptide antibiotics. Curr Opin Chem Biol 2013; 17:626-34. [PMID: 23838388 DOI: 10.1016/j.cbpa.2013.06.021] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2013] [Revised: 06/04/2013] [Accepted: 06/17/2013] [Indexed: 11/16/2022]
Abstract
Nosiheptide is an archetypal thiopeptide antibiotic, possessing a characteristic macrocyclic core that contains a 6-membered heterocycle central to multiple azol(in)es and dehydroamino acids. The discovery of the ribosomal origin of thiopeptides revealed a unifying theme, showing that the structural complexity arises from post-translational modifications (PTMs) of precursor peptides. Thiopeptide framework formation proceeds via cyclodehydration/dehydrogenation (for azol(in)es), dehydration (for dehydroamino acids), and cycloaddition (for the central heterocycle domain). This common process has not been reproduced in vitro, partly due to the poorly understood logic of thiopeptide biosynthetic pathways. Utilizing nosiheptide biosynthesis as a model system, we herein consider how nature coordinates a number of highly interwined, common and specific PTMs to accomplish the complexity of ribosomally synthesized and post-translationally modified peptides.
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Affiliation(s)
- Shoufeng Wang
- State Key Laboratory of Bioorganic and Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China
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44
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Small MC, Lopes P, Andrade RB, MacKerell AD. Impact of ribosomal modification on the binding of the antibiotic telithromycin using a combined grand canonical monte carlo/molecular dynamics simulation approach. PLoS Comput Biol 2013; 9:e1003113. [PMID: 23785274 PMCID: PMC3681621 DOI: 10.1371/journal.pcbi.1003113] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Accepted: 05/07/2013] [Indexed: 02/05/2023] Open
Abstract
Resistance to macrolide antibiotics is conferred by mutation of A2058 to G or methylation by Erm methyltransferases of the exocyclic N6 of A2058 (E. coli numbering) that forms the macrolide binding site in the 50S subunit of the ribosome. Ketolides such as telithromycin mitigate A2058G resistance yet remain susceptible to Erm-based resistance. Molecular details associated with macrolide resistance due to the A2058G mutation and methylation at N6 of A2058 by Erm methyltransferases were investigated using empirical force field-based simulations. To address the buried nature of the macrolide binding site, the number of waters within the pocket was allowed to fluctuate via the use of a Grand Canonical Monte Carlo (GCMC) methodology. The GCMC water insertion/deletion steps were alternated with Molecular Dynamics (MD) simulations to allow for relaxation of the entire system. From this GCMC/MD approach information on the interactions between telithromycin and the 50S ribosome was obtained. In the wild-type (WT) ribosome, the 2'-OH to A2058 N1 hydrogen bond samples short distances with a higher probability, while the effectiveness of telithromycin against the A2058G mutation is explained by a rearrangement of the hydrogen bonding pattern of the 2'-OH to 2058 that maintains the overall antibiotic-ribosome interactions. In both the WT and A2058G mutation there is significant flexibility in telithromycin's imidazole-pyridine side chain (ARM), indicating that entropic effects contribute to the binding affinity. Methylated ribosomes show lower sampling of short 2'-OH to 2058 distances and also demonstrate enhanced G2057-A2058 stacking leading to disrupted A752-U2609 Watson-Crick (WC) interactions as well as hydrogen bonding between telithromycin's ARM and U2609. This information will be of utility in the rational design of novel macrolide analogs with improved activity against methylated A2058 ribosomes.
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Affiliation(s)
- Meagan C. Small
- Department of Pharmaceutical Sciences, University of Maryland, Baltimore, Maryland, United States of America
| | - Pedro Lopes
- Department of Pharmaceutical Sciences, University of Maryland, Baltimore, Maryland, United States of America
| | - Rodrigo B. Andrade
- Department of Chemistry, Temple University, Philadelphia, Pennsylvania, United States of America
| | - Alexander D. MacKerell
- Department of Pharmaceutical Sciences, University of Maryland, Baltimore, Maryland, United States of America
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45
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Tourigny DS, Fernández IS, Kelley AC, Vakiti RR, Chattopadhyay AK, Dorich S, Hanessian S, Ramakrishnan V. Crystal structure of a bioactive pactamycin analog bound to the 30S ribosomal subunit. J Mol Biol 2013; 425:3907-10. [PMID: 23702293 PMCID: PMC3794158 DOI: 10.1016/j.jmb.2013.05.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Revised: 05/13/2013] [Accepted: 05/14/2013] [Indexed: 11/03/2022]
Abstract
Biosynthetically and chemically derived analogs of the antibiotic pactamycin and de-6-methylsalicylyl (MSA)-pactamycin have attracted recent interest as potential antiprotozoal and antitumor drugs. Here, we report a 3.1-Å crystal structure of de-6-MSA-pactamycin bound to its target site on the Thermus thermophilus 30S ribosomal subunit. Although de-6-MSA-pactamycin lacks the MSA moiety, it shares the same binding site as pactamycin and induces a displacement of nucleic acid template bound at the E-site of the 30S. The structure highlights unique interactions between this pactamycin analog and the ribosome, which paves the way for therapeutic development of related compounds.
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Affiliation(s)
- David S Tourigny
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
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46
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Velagapudi SP, Disney MD. Defining RNA motif-aminoglycoside interactions via two-dimensional combinatorial screening and structure-activity relationships through sequencing. Bioorg Med Chem 2013; 21:6132-8. [PMID: 23719281 DOI: 10.1016/j.bmc.2013.04.072] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2012] [Revised: 04/12/2013] [Accepted: 04/19/2013] [Indexed: 10/26/2022]
Abstract
RNA is an extremely important target for the development of chemical probes of function or small molecule therapeutics. Aminoglycosides are the most well studied class of small molecules to target RNA. However, the RNA motifs outside of the bacterial rRNA A-site that are likely to be bound by these compounds in biological systems is largely unknown. If such information were known, it could allow for aminoglycosides to be exploited to target other RNAs and, in addition, could provide invaluable insights into potential bystander targets of these clinically used drugs. We utilized two-dimensional combinatorial screening (2DCS), a library-versus-library screening approach, to select the motifs displayed in a 3×3 nucleotide internal loop library and in a 6-nucleotide hairpin library that bind with high affinity and selectivity to six aminoglycoside derivatives. The selected RNA motifs were then analyzed using structure-activity relationships through sequencing (StARTS), a statistical approach that defines the privileged RNA motif space that binds a small molecule. StARTS allowed for the facile annotation of the selected RNA motif-aminoglycoside interactions in terms of affinity and selectivity. The interactions selected by 2DCS generally have nanomolar affinities, which is higher affinity than the binding of aminoglycosides to a mimic of their therapeutic target, the bacterial rRNA A-site.
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Affiliation(s)
- Sai Pradeep Velagapudi
- Department of Chemistry, The Scripps Research Institute, Jupiter, FL 33458, United States; Department of Chemistry, University at Buffalo, Buffalo, NY 14620, United States
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47
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Wrzesinski J, Błaszczyk L, Wrońska M, Kasprowicz A, Stokowa-Sołtys K, Nagaj J, Szafraniec M, Kulinski T, Jeżowska-Bojczuk M, Ciesiołka J. Mapping the interactions of selected antibiotics and their Cu2+complexes with the antigenomic delta ribozyme. FEBS J 2013; 280:2652-64. [DOI: 10.1111/febs.12257] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Revised: 03/15/2013] [Accepted: 03/18/2013] [Indexed: 11/30/2022]
Affiliation(s)
- Jan Wrzesinski
- Institute of Bioorganic Chemistry; Polish Academy of Sciences; Poznań; Poland
| | - Leszek Błaszczyk
- Institute of Bioorganic Chemistry; Polish Academy of Sciences; Poznań; Poland
| | | | | | | | | | - Milena Szafraniec
- Institute of Bioorganic Chemistry; Polish Academy of Sciences; Poznań; Poland
| | - Tadeusz Kulinski
- Institute of Bioorganic Chemistry; Polish Academy of Sciences; Poznań; Poland
| | | | - Jerzy Ciesiołka
- Institute of Bioorganic Chemistry; Polish Academy of Sciences; Poznań; Poland
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48
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Wang L, Wasserman MR, Feldman MB, Altman RB, Blanchard SC. Mechanistic insights into antibiotic action on the ribosome through single-molecule fluorescence imaging. Ann N Y Acad Sci 2013; 1241:E1-16. [PMID: 23419024 DOI: 10.1111/j.1749-6632.2012.06839.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Single-molecule fluorescence imaging has provided unprecedented access to the dynamics of ribosome function, revealing transient intermediate states that are critical to ribosome activity. Imaging platforms have now been developed that are capable of probing many hundreds of molecules simultaneously at temporal and spatial resolutions approaching the sub-millisecond time and the sub-nanometer scales. These advances enable both steady- and pre-steady state measurements of individual steps in the translation process as well as processive reactions. The data generated using these methods have yielded new, quantitative structural and kinetic insights into ribosomal activity. They have also shed light on the mechanisms of antibiotic targeting the translation apparatus, revealing features of the structure-function relationship that would be difficult to obtain by other means. This review provides an overview of the types of information that can be obtained using such imaging platforms and a blueprint for using the technique to assess how small-molecule antibiotics alter macromolecular functions.
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Affiliation(s)
- Leyi Wang
- Department of Physiology and Biophysics, Weill Cornell Medical College, New York, NY 10065, USA
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49
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Inhibition of ribosomal subunit synthesis in Escherichia coli by the vanadyl ribonucleoside complex. Curr Microbiol 2013; 67:226-33. [PMID: 23512123 DOI: 10.1007/s00284-013-0350-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2012] [Accepted: 02/20/2013] [Indexed: 01/28/2023]
Abstract
The increase in antibiotic-resistant microorganisms has driven a search for new antibiotic targets and novel antimicrobial agents. A large number of different antibiotics target bacterial ribosomal subunit formation. Several specific ribonucleases are important in the processing of rRNA during subunit biogenesis. This work demonstrates that the ribonuclease inhibitor, vanadyl ribonucleoside complex (VRC), can inhibit RNases involved in ribosomal subunit formation. The ribosomal subunit synthesis rate was significantly decreased and ribosomal RNA from the subunit precursors was degraded. VRC had no inhibitory effect on translation. VRC also potentiated the inhibitory effects of an aminoglycoside and a macrolide antibiotic.
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50
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Abstract
This is a review of RNA as a target for small molecules (ribosomes, riboswitches, regulatory RNAs) and RNA-derived oligonucleotides as tools (antisense/small interfering RNA, ribozymes, aptamers/decoy RNA and microRNA). This review highlights the present state of research using RNA as a drug target or as a potential drug candidate and explains at which stage and to what extent rational design could eventually be involved. Special attention has been paid to the recent potential clinical applications of RNA either as drugs or drug targets. The review deals mainly with mechanistic approaches rather than with physicochemical or computational aspects of RNA-based drug design.
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Affiliation(s)
- Irene M Lagoja
- Katholieke Universiteit Leuven, Laboratory of Medicinal Chemistry, Rega Institute for Medical Research, Minderbroedersstraat 10, B-3000 Leuven, Belgium +32 16 337396 ; +32 16 337340 ;
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