1
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Abedeera SM, Jayalath KS, Xie J, Rauff RM, Abeysirigunawardena SC. Pseudouridine Synthase RsuA Confers a Survival Advantage to Bacteria under Streptomycin Stress. Antibiotics (Basel) 2023; 12:1447. [PMID: 37760743 PMCID: PMC10525438 DOI: 10.3390/antibiotics12091447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 08/28/2023] [Accepted: 09/08/2023] [Indexed: 09/29/2023] Open
Abstract
Bacterial ribosome small subunit rRNA (16S rRNA) contains 11 nucleotide modifications scattered throughout all its domains. The 16S rRNA pseudouridylation enzyme, RsuA, which modifies U516, is a survival protein essential for bacterial survival under stress conditions. A comparison of the growth curves of wildtype and RsuA knock-out E. coli strains illustrates that RsuA renders a survival advantage to bacteria under streptomycin stress. The RsuA-dependent growth advantage for bacteria was found to be dependent on its pseudouridylation activity. In addition, the role of RsuA as a trans-acting factor during ribosome biogenesis may also play a role in bacterial growth under streptomycin stress. Furthermore, circular dichroism spectroscopy measurements and RNase footprinting studies have demonstrated that pseudouridine at position 516 influences helix 18 structure, folding, and streptomycin binding. This study exemplifies the importance of bacterial rRNA modification enzymes during environmental stress.
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Affiliation(s)
| | | | | | | | - Sanjaya C. Abeysirigunawardena
- Department of Chemistry and Biochemistry, Kent State University, 1175 Risman Dr., Kent, OH 44242, USA; (S.M.A.); (K.S.J.); (J.X.); (R.M.R.)
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2
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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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3
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GC K, To D, Jayalath K, Abeysirigunawardena S. Discovery of a novel small molecular peptide that disrupts helix 34 of bacterial ribosomal RNA. RSC Adv 2019; 9:40268-40276. [PMID: 35542650 PMCID: PMC9076165 DOI: 10.1039/c9ra07812f] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 11/25/2019] [Indexed: 12/14/2022] Open
Abstract
Despite the advances in modern medicine, antibiotic resistance is a persistent and growing threat to the world. Thus, the discovery and development of novel antibiotics have become crucial to combat multi-drug resistant pathogens. The goal of our research is to discover a small molecular peptide that can disrupt the synthesis of new ribosomes. Using the phage display technique, we have discovered a 7-mer peptide that binds to the second strand of 16S h34 RNA with a dissociation constant in the low micromolar range. Binding of the peptide alters RNA structure and inhibits the binding of the ribosomal RNA small subunit methyltransferase C (RsmC) enzyme that methylates the exocyclic amine of G1207. The addition of this peptide also increases the lag phase of bacterial growth. Introduction of chemical modifications to increase the binding affinity of the peptide to RNA, its uptake and stability can further improve the efficacy of the peptide as an antibiotic agent against pathogenic bacteria. Discovery of a novel heptapeptide that disrupts RNA–RNA and RNA–protein interactions in bacterial ribosome.![]()
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Affiliation(s)
- Keshav GC
- Department of Chemistry and Biochemistry
- Kent State University
- Kent
- USA
| | - Davidnhan To
- Department of Chemistry and Biochemistry
- Kent State University
- Kent
- USA
| | - Kumudie Jayalath
- Department of Chemistry and Biochemistry
- Kent State University
- Kent
- USA
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4
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Sakakibara Y, Chow CS. Pseudouridine modifications influence binding of aminoglycosides to helix 69 of bacterial ribosomes. Org Biomol Chem 2017; 15:8535-8543. [PMID: 28959821 PMCID: PMC5663508 DOI: 10.1039/c7ob02147j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Development of antibiotics that target new regions of functionality is a possible way to overcome antibiotic resistance. In this study, the interactions of aminoglycoside antibiotics with helix 69 of the E. coli 23S rRNA in the context of complete 70S ribosomes or the isolated 50S subunit were investigated by using chemical probing and footprinting analysis. Helix 69 is a dynamic RNA motif that plays major roles in bacterial ribosome activity. Neomycin, paromomycin, and gentamicin interact with the stem region of helix 69 in complete 70S ribosomes, but have diminished binding to the isolated 50S subunit. Pseudouridine modifications in helix 69 were shown to impact the aminoglycoside interactions. These results suggest a requirement for a specific conformational state of helix 69 for efficient aminoglycoside binding, and imply that this motif may be a suitable target for mechanism-based therapeutics.
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Affiliation(s)
- Yogo Sakakibara
- Department of Chemistry, Wayne State University, Detroit, MI 48202, USA.
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5
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Kulik M, Markowska-Zagrajek A, Wojciechowska M, Grzela R, Wituła T, Trylska J. Helix 69 of Escherichia coli 23S ribosomal RNA as a peptide nucleic acid target. Biochimie 2017; 138:32-42. [PMID: 28396015 DOI: 10.1016/j.biochi.2017.04.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2016] [Revised: 03/03/2017] [Accepted: 04/03/2017] [Indexed: 10/19/2022]
Abstract
A fragment of 23S ribosomal RNA (nucleotides 1906-1924 in E. coli), termed Helix 69, forms a hairpin that is essential for ribosome function. Helix 69 forms a conformationally flexible inter-subunit connection with helix 44 of 16S ribosomal RNA, and the nucleotide A1913 of Helix 69 influences decoding accuracy. Nucleotides U1911 and U1917 are post-transcriptionally modified with pseudouridines (Ψ) and U1915 with 3-methyl-Ψ. We investigated Helix 69 as a target for a complementary synthetic oligonucleotide - peptide nucleic acid (PNA). We determined thermodynamic properties of Helix 69 and its complexes with PNA and tested the performance of PNA targeted at Helix 69 in inhibiting translation in cell-free extracts and growth of E. coli cells. First, we examined the interactions of a PNA oligomer complementary to the G1907-A1919 fragment of Helix 69 with the sequences corresponding to human and bacterial species (with or without pseudouridine modifications). PNA invades the Helix 69 hairpin creating stable complexes and PNA binding to the pseudouridylated bacterial sequence is stronger than to Helix 69 without any modifications. Second, we confirmed the binding of PNA to 23S rRNA and 70S ribosomes. Third, we verified the efficiency of translation inhibition of these PNA oligomers in the cell-free translation/transcription E. coli system, which were in a similar range as tetracycline. Next, we confirmed that PNA conjugated to the (KFF)3K transporter peptide inhibited E. coli growth in micromolar concentrations. Overall, targeting Helix 69 with PNA or other sequence-specific oligomers could be a promising way to inhibit bacterial translation.
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Affiliation(s)
- Marta Kulik
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097, Warsaw, Poland; Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093, Warsaw, Poland
| | - Agnieszka Markowska-Zagrajek
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097, Warsaw, Poland; Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096, Warsaw, Poland
| | - Monika Wojciechowska
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097, Warsaw, Poland
| | - Renata Grzela
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097, Warsaw, Poland
| | - Tomasz Wituła
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097, Warsaw, Poland
| | - Joanna Trylska
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097, Warsaw, Poland.
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6
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Dedduwa-Mudalige GNP, Chow CS. Cisplatin Targeting of Bacterial Ribosomal RNA Hairpins. Int J Mol Sci 2015; 16:21392-409. [PMID: 26370969 PMCID: PMC4613259 DOI: 10.3390/ijms160921392] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Revised: 08/26/2015] [Accepted: 08/29/2015] [Indexed: 01/11/2023] Open
Abstract
Cisplatin is a clinically important chemotherapeutic agent known to target purine bases in nucleic acids. In addition to major deoxyribonucleic acid (DNA) intrastrand cross-links, cisplatin also forms stable adducts with many types of ribonucleic acid (RNA) including siRNA, spliceosomal RNAs, tRNA, and rRNA. All of these RNAs play vital roles in the cell, such as catalysis of protein synthesis by rRNA, and therefore serve as potential drug targets. This work focused on platination of two highly conserved RNA hairpins from E. coli ribosomes, namely pseudouridine-modified helix 69 from 23S rRNA and the 790 loop of helix 24 from 16S rRNA. RNase T1 probing, MALDI mass spectrometry, and dimethyl sulfate mapping revealed platination at GpG sites. Chemical probing results also showed platination-induced RNA structural changes. These findings reveal solvent and structural accessibility of sites within bacterial RNA secondary structures that are functionally significant and therefore viable targets for cisplatin as well as other classes of small molecules. Identifying target preferences at the nucleotide level, as well as determining cisplatin-induced RNA conformational changes, is important for the design of more potent drug molecules. Furthermore, the knowledge gained through studies of RNA-targeting by cisplatin is applicable to a broad range of organisms from bacteria to human.
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Affiliation(s)
| | - Christine S Chow
- Department of Chemistry, Wayne State University, Detroit, MI 48202, USA.
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7
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Jiang J, Kharel DN, Chow CS. Modulation of conformational changes in helix 69 mutants by pseudouridine modifications. Biophys Chem 2015; 200-201:48-55. [PMID: 25800680 DOI: 10.1016/j.bpc.2015.03.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2015] [Revised: 03/02/2015] [Accepted: 03/02/2015] [Indexed: 11/25/2022]
Abstract
Centrally located at the ribosomal subunit interface and mRNA tunnel, helix 69 (H69) from 23S rRNA participates in key steps of translation. Ribosome activity is influenced by three pseudouridine modifications, which modulate the structure and conformational behavior of H69. To understand how H69 is affected by the presence of pseudouridine in combination with sequence changes, the biophysical properties of wild-type H69 and representative mutants (A1912G, U1917C, and A1919G) were examined. Results from NMR and circular dichroism spectroscopy indicate that pH-dependent structural changes of wild-type H69 and the chosen mutants are modulated by pseudouridine and loop sequence. The effects of the mutations on global stability of H69 are negligible; however, pseudouridine stabilizes H69 at low pH conditions. Alterations to induced conformational changes of H69 likely result in compromised function, as indicated by previous biological studies.
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Affiliation(s)
- Jun Jiang
- Department of Chemistry, Wayne State University, Detroit, MI 48202, United States
| | - Daya Nidhi Kharel
- Department of Chemistry, Wayne State University, Detroit, MI 48202, United States
| | - Christine S Chow
- Department of Chemistry, Wayne State University, Detroit, MI 48202, United States.
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8
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Spenkuch F, Motorin Y, Helm M. Pseudouridine: still mysterious, but never a fake (uridine)! RNA Biol 2014; 11:1540-54. [PMID: 25616362 PMCID: PMC4615568 DOI: 10.4161/15476286.2014.992278] [Citation(s) in RCA: 146] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Revised: 09/23/2014] [Accepted: 10/10/2014] [Indexed: 01/15/2023] Open
Abstract
Pseudouridine (Ψ) is the most abundant of >150 nucleoside modifications in RNA. Although Ψ was discovered as the first modified nucleoside more than half a century ago, neither the enzymatic mechanism of its formation, nor the function of this modification are fully elucidated. We present the consistent picture of Ψ synthases, their substrates and their substrate positions in model organisms of all domains of life as it has emerged to date and point out the challenges that remain concerning higher eukaryotes and the elucidation of the enzymatic mechanism.
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MESH Headings
- Escherichia coli/genetics
- Escherichia coli/metabolism
- Humans
- Intramolecular Transferases/genetics
- Intramolecular Transferases/metabolism
- Isoenzymes/genetics
- Isoenzymes/metabolism
- Nucleic Acid Conformation
- Pseudouridine/metabolism
- RNA/genetics
- RNA/metabolism
- RNA Processing, Post-Transcriptional
- RNA, Mitochondrial
- RNA, Ribosomal/genetics
- RNA, Ribosomal/metabolism
- RNA, Transfer, Amino Acid-Specific/chemistry
- RNA, Transfer, Amino Acid-Specific/genetics
- RNA, Transfer, Amino Acid-Specific/metabolism
- Ribonucleoproteins, Small Nuclear/genetics
- Ribonucleoproteins, Small Nuclear/metabolism
- Ribosomes/chemistry
- Ribosomes/metabolism
- Saccharomyces cerevisiae/genetics
- Saccharomyces cerevisiae/metabolism
- Uridine/metabolism
- RNA, Guide, CRISPR-Cas Systems
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Affiliation(s)
- Felix Spenkuch
- Institute of Pharmacy and Biochemistry; Johannes Gutenberg-University of Mainz; Mainz, Germany
| | - Yuri Motorin
- Laboratoire IMoPA; Ingénierie Moléculaire et Physiopathologie Articulaire; BioPôle de l'Université de Lorraine; Campus Biologie-Santé; Faculté de Médecine; Vandoeuvre-les-Nancy Cedex, France
| | - Mark Helm
- Institute of Pharmacy and Biochemistry; Johannes Gutenberg-University of Mainz; Mainz, Germany
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9
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Jiang J, Aduri R, Chow CS, SantaLucia J. Structure modulation of helix 69 from Escherichia coli 23S ribosomal RNA by pseudouridylations. Nucleic Acids Res 2013; 42:3971-81. [PMID: 24371282 PMCID: PMC3973299 DOI: 10.1093/nar/gkt1329] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Helix 69 (H69) is a 19-nt stem-loop region from the large subunit ribosomal RNA. Three pseudouridine (Ψ) modifications clustered in H69 are conserved across phylogeny and known to affect ribosome function. To explore the effects of Ψ on the conformations of Escherichia coli H69 in solution, nuclear magnetic resonance spectroscopy was used to reveal the structural differences between H69 with (ΨΨΨ) and without (UUU) Ψ modifications. Comparison of the two structures shows that H69 ΨΨΨ has the following unique features: (i) the loop region is closed by a Watson-Crick base pair between Ψ1911 and A1919, which is potentially reinforced by interactions involving Ψ1911N1H and (ii) Ψ modifications at loop residues 1915 and 1917 promote base stacking from Ψ1915 to A1918. In contrast, the H69 UUU loop region, which lacks Ψ modifications, is less organized. Structure modulation by Ψ leads to alteration in conformational behavior of the 5' half of the H69 loop region, observed as broadening of C1914 non-exchangeable base proton resonances in the H69 ΨΨΨ nuclear magnetic resonance spectra, and plays an important biological role in establishing the ribosomal intersubunit bridge B2a and mediating translational fidelity.
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Affiliation(s)
- Jun Jiang
- Department of Chemistry, Wayne State University, Detroit, MI 48202, USA
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10
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Kierzek E, Malgowska M, Lisowiec J, Turner DH, Gdaniec Z, Kierzek R. The contribution of pseudouridine to stabilities and structure of RNAs. Nucleic Acids Res 2013; 42:3492-501. [PMID: 24369424 PMCID: PMC3950712 DOI: 10.1093/nar/gkt1330] [Citation(s) in RCA: 154] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Thermodynamic data are reported revealing that pseudouridine (Ψ) can stabilize RNA duplexes when replacing U and forming Ψ-A, Ψ-G, Ψ-U and Ψ-C pairs. Stabilization is dependent on type of base pair, position of Ψ within the RNA duplex, and type and orientation of adjacent Watson–Crick pairs. NMR spectra demonstrate that for internal Ψ-A, Ψ-G and Ψ-U pairs, the N3 imino proton is hydrogen bonded to the opposite strand nucleotide and the N1 imino proton may also be hydrogen bonded. CD spectra show that general A-helix structure is preserved, but there is some shifting of peaks and changing of intensities. Ψ has two hydrogen donors (N1 and N3 imino protons) and two hydrogen bond acceptors because the glycosidic bond is C-C rather than C-N as in uridine. This greater structural potential may allow Ψ to behave as a kind of structurally driven universal base because it can enhance stability relative to U when paired with A, G, U or C inside a double helix. These structural and thermodynamic properties may contribute to the biological functions of Ψ.
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Affiliation(s)
- Elzbieta Kierzek
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, 61-704 Poznan, Noskowskiego 12/14, Poland and Department of Chemistry, University of Rochester, Rochester, NY 14627, USA
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11
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Goh GB, Knight JL, Brooks CL. Towards Accurate Prediction of Protonation Equilibrium of Nucleic Acids. J Phys Chem Lett 2013; 4:760-766. [PMID: 23526474 PMCID: PMC3601767 DOI: 10.1021/jz400078d] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The role of protonated nucleotides in modulating the pH-dependent properties of nucleic acids is one of the emerging frontiers in the field of nucleic acid biology. The recent development of a constant pH molecular dynamics simulation (CPHMDMSλD) framework for simulating nucleic acids has provided a tool for realistic simulations of pH-dependent dynamics. We enhanced the CPHMDMSλD framework with pH-based replica exchange (pH-REX), which significantly improves the sampling of both titration and spatial coordinates. The results from our pKa calculations for the GAAA tetraloop, which was predicted with lower accuracy previously due to sampling challenges, demonstrates that pH-REX reduces the average unsigned error (AUE) to 0.7 pKa units, and the error of the most poorly predicted residue A17 was drastically reduced from 2.9 to 1.2 pKa unit. Lastly, we show that pH-REX CPHMDMSλD simulations can be used to identify the dominant conformation of nucleic acid structures in alternate pH environments. This work suggests that pH-REX CPHMDMSλD simulations provide a practical tool for predicting nucleic acid protonation equilibrium from first-principles, and offering structural and mechanistic insight into the study of pH-dependent properties of nucleic acids.
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Affiliation(s)
- Garrett B Goh
- Department of Chemistry, University of Michigan, 930 N. University, Ann Arbor, Michigan 48109, United States
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12
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Abstract
The role of pH-dependent protonation equilibrium in modulating RNA dynamics and function is one of the key unanswered questions in RNA biology. Molecular dynamics (MD) simulations can provide insight into the mechanistic roles of protonated nucleotides, but it is only capable of modeling fixed protonation states and requires prior knowledge of the key residue's protonation state. Recently, we developed a framework for constant pH molecular dynamics simulations (CPHMDMSλD) of nucleic acids, where the nucleotides' protonation states are modeled as dynamic variables that are coupled to the structural dynamics of the RNA. In the present study, we demonstrate the application of CPHMDMSλD to the lead-dependent ribozyme; establishing the validity of this approach for modeling complex RNA structures. We show that CPHMDMSλD accurately predicts the direction of the pKa shifts and reproduces experimentally-measured microscopic pKa values with an average unsigned error of 1.3 pKa units. The effects of coupled titration states in RNA structures are modeled, and the importance of conformation sampling is highlighted. The general accuracy of CPHMDMSλD simulations in reproducing pH-dependent observables reported in this work demonstrates that constant pH simulations provides a powerful tool to investigate pH-dependent processes in nucleic acids.
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Affiliation(s)
- Garrett B Goh
- Department of Chemistry, University of Michigan, 930 N. University, Ann Arbor, Michigan 48109, United States
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13
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Kaur M, Rupasinghe CN, Klosi E, Spaller MR, Chow CS. Selection of heptapeptides that bind helix 69 of bacterial 23S ribosomal RNA. Bioorg Med Chem 2013; 21:1240-7. [PMID: 23375098 DOI: 10.1016/j.bmc.2012.12.048] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2012] [Revised: 12/13/2012] [Accepted: 12/20/2012] [Indexed: 11/16/2022]
Abstract
Helix 69 of Escherichia coli 23S rRNA has important roles in specific steps of translation, such as subunit association, translocation, and ribosome recycling. An M13 phage library was used to identify peptide ligands with affinity for helix 69. One selected sequence, NQVANHQ, was shown through a bead assay to interact with helix 69. Electrospray ionization mass spectroscopy revealed an apparent dissociation constant for the amidated peptide and helix 69 in the low micromolar range. This value is comparable to that of aminoglycoside antibiotics binding to the A site of 16S rRNA or helix 69. Helix 69 variants (human) and unrelated RNAs (helix 31 or A site of 16S rRNA) showed two- to fourfold lower affinity for NQVANHQ-NH(2). These results suggest that the peptide has desirable features for development as a lead compound for novel antimicrobials.
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Affiliation(s)
- Moninderpal Kaur
- Department of Chemistry, Wayne State University, Detroit, MI 48202, USA
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14
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Sakakibara Y, Abeysirigunawardena SC, Duc ACE, Dremann DN, Chow CS. Ligand- and pH-Induced Conformational Changes of RNA Domain Helix 69 Revealed by 2-Aminopurine Fluorescence. Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201206000] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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15
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Sakakibara Y, Abeysirigunawardena SC, Duc ACE, Dremann DN, Chow CS. Ligand- and pH-induced conformational changes of RNA domain helix 69 revealed by 2-aminopurine fluorescence. Angew Chem Int Ed Engl 2012; 51:12095-8. [PMID: 23097282 DOI: 10.1002/anie.201206000] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Indexed: 11/07/2022]
Affiliation(s)
- Yogo Sakakibara
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, USA
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16
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Sakakibara Y, Chow CS. Role of pseudouridine in structural rearrangements of helix 69 during bacterial ribosome assembly. ACS Chem Biol 2012; 7:871-8. [PMID: 22324880 DOI: 10.1021/cb200497q] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
As part of the central core domain of the ribosome, helix 69 of 23S rRNA participates in an important intersubunit bridge and contacts several protein translation factors. Helix 69 is believed to play key roles in protein synthesis. Even though high-resolution crystal structures of the ribosome exist, the solution dynamics and roles of individual nucleotides in H69 are still not well-defined. To better understand the influence of modified nucleotides, specifically pseudouridine, on the multiple conformational states of helix 69 in the context of 50S subunits and 70S ribosomes, chemical probing analyses were performed on wild-type and pseudouridine-deficient bacterial ribosomes. Local structural rearrangements of helix 69 upon ribosomal subunit association and interactions with its partner, helix 44 of 16S rRNA, are observed. The helix 69 conformational states are also magnesium-dependent. The probing data presented in this study provide insight into the functional role of helix 69 dynamics and regulation of these conformational states by post-transcriptional pseudouridine modification.
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Affiliation(s)
- Yogo Sakakibara
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, United
States
| | - Christine S. Chow
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, United
States
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17
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Sumita M, Jiang J, SantaLucia J, Chow CS. Comparison of solution conformations and stabilities of modified helix 69 rRNA analogs from bacteria and human. Biopolymers 2011; 97:94-106. [PMID: 21858779 DOI: 10.1002/bip.21706] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2011] [Accepted: 07/31/2011] [Indexed: 12/20/2022]
Abstract
The helix 69 (H69) region of the large subunit (28S) ribosomal RNA (rRNA) of Homo sapiens contains five pseudouridine (Ψ) residues out of 19 total nucleotides, three of which are highly conserved. In this study, the effects of this abundant modified nucleotide on the structure and stability of H69 were compared with those of uridine in double-stranded (stem) regions. These results were compared with previous hairpin (stem plus single-stranded loop) studies to understand the contributions of the loop sequences to H69 structure and stability. The role of a loop nucleotide substitution from an A in bacteria (position 1918 in Escherichia coli 23S rRNA) to a G in eukaryotes (position 3734 in H. sapiens 28S rRNA) was examined. Thermodynamic parameters for the duplex RNAs were obtained through UV melting studies, and differences in the modified and unmodified RNA structures were examined by circular dichroism spectroscopy. The overall folded structure of human H69 appears to be similar to the bacterial RNA, consistent with the idea that ribosome structure and function are highly conserved; however, our results reveal subtle differences in structure and stability between the bacterial and human H69 RNAs in both the stem and loop regions. These findings may be significant with respect to H69 as a potential drug target site.
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Affiliation(s)
- Minako Sumita
- Department of Chemistry, Wayne State University, Detroit, MI 48202, USA
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18
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Sakakibara Y, Chow CS. Probing conformational states of modified helix 69 in 50S ribosomes. J Am Chem Soc 2011; 133:8396-9. [PMID: 21557607 DOI: 10.1021/ja2005658] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The movement of the small ribosomal subunit (30S) relative to the large ribosomal subunit (50S) during translation is widely known, but many molecular details and roles of rRNA and proteins in this process are still undefined, especially in solution models. The functional relationship of modified nucleotides to ribosome activity is one such enigma. To better understand ribosome dynamics and the influence of modified nucleotides on such processes, the focus of this work was helix 69 of 23S rRNA, which contains three pseudouridine residues in its loop region. Ribosome probing experiments with dimethylsulfate revealed that specific base accessibilities and individual nucleotide conformations in helix 69 are influenced differently by pH, temperature, magnesium, and the presence of pseudouridine modifications.
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Affiliation(s)
- Yogo Sakakibara
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, USA
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19
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O'Connor M, Gregory ST. Inactivation of the RluD pseudouridine synthase has minimal effects on growth and ribosome function in wild-type Escherichia coli and Salmonella enterica. J Bacteriol 2011; 193:154-62. [PMID: 21037010 PMCID: PMC3019933 DOI: 10.1128/jb.00970-10] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2010] [Accepted: 10/18/2010] [Indexed: 11/20/2022] Open
Abstract
The Escherichia coli rluD gene encodes a pseudouridine synthase responsible for the pseudouridine (Ψ) modifications at positions 1911, 1915, and 1917 in helix 69 of 23S rRNA. It has been reported that deletion of rluD in K-12 strains of E. coli is associated with extremely slow growth, increased readthrough of stop codons, and defects in 50S ribosomal subunit assembly and 30S-50S subunit association. Suppressor mutations in the prfB and prfC genes encoding release factor 2 (RF2) and RF3 that restore the wild type-growth rate and also correct the ribosomal defects have now been isolated. These suppressors link helix 69 Ψ residues with the termination phase of protein synthesis. However, further genetic analysis reported here also reveals that the slow growth and other defects associated with inactivation of rluD in E. coli K-12 strains are due to a defective RF2 protein, with a threonine at position 246, which is present in all K-12 strains. This is in contrast to the more typical alanine found at this position in most bacterial RF2s, including those of other E. coli strains. Inactivation of rluD in E. coli strains containing the prfB allele from E. coli B or in Salmonella enterica, both carrying an RF2 with Ala246, has negligible effects on growth, termination, or ribosome function. The results indicate that, in contrast to those in wild bacteria, termination functions in E. coli K-12 strains carrying a partially defective RF2 protein are especially susceptible to perturbation of ribosome-RF interactions, such as that caused by loss of h69 Ψ modifications.
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Affiliation(s)
- Michael O'Connor
- School of Biological Sciences, University of Missouri-Kansas City, 5007 Rockhill Rd, Kansas City, Missouri 64110, USA.
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Scheunemann AE, Graham WD, Vendeix FAP, Agris PF. Binding of aminoglycoside antibiotics to helix 69 of 23S rRNA. Nucleic Acids Res 2010; 38:3094-105. [PMID: 20110260 PMCID: PMC2875026 DOI: 10.1093/nar/gkp1253] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Aminoglycosides antibiotics negate dissociation and recycling of the bacterial ribosome’s subunits by binding to Helix 69 (H69) of 23S rRNA. The differential binding of various aminoglycosides to the chemically synthesized terminal domains of the Escherichia coli and human H69 has been characterized using spectroscopy, calorimetry and NMR. The unmodified E. coli H69 hairpin exhibited a significantly higher affinity for neomycin B and tobramycin than for paromomycin (Kds = 0.3 ± 0.1, 0.2 ± 0.2 and 5.4 ± 1.1 µM, respectively). The binding of streptomycin was too weak to assess. In contrast to the E. coli H69, the human 28S rRNA H69 had a considerable decrease in affinity for the antibiotics, an important validation of the bacterial target. The three conserved pseudouridine modifications (Ψ1911, Ψ1915, Ψ1917) occurring in the loop of the E. coli H69 affected the dissociation constant, but not the stoichiometry for the binding of paromomycin (Kd = 2.6 ± 0.1 µM). G1906 and G1921, observed by NMR spectrometry, figured predominantly in the aminoglycoside binding to H69. The higher affinity of the E. coli H69 for neomycin B and tobramycin, as compared to paromomycin and streptomycin, indicates differences in the efficacy of the aminoglycosides.
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Affiliation(s)
- Ann E Scheunemann
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC 27695-7622, USA
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Grosjean H, Gaspin C, Marck C, Decatur WA, de Crécy-Lagard V. RNomics and Modomics in the halophilic archaea Haloferax volcanii: identification of RNA modification genes. BMC Genomics 2008; 9:470. [PMID: 18844986 PMCID: PMC2584109 DOI: 10.1186/1471-2164-9-470] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2008] [Accepted: 10/09/2008] [Indexed: 12/14/2022] Open
Abstract
Background Naturally occurring RNAs contain numerous enzymatically altered nucleosides. Differences in RNA populations (RNomics) and pattern of RNA modifications (Modomics) depends on the organism analyzed and are two of the criteria that distinguish the three kingdoms of life. If the genomic sequences of the RNA molecules can be derived from whole genome sequence information, the modification profile cannot and requires or direct sequencing of the RNAs or predictive methods base on the presence or absence of the modifications genes. Results By employing a comparative genomics approach, we predicted almost all of the genes coding for the t+rRNA modification enzymes in the mesophilic moderate halophile Haloferax volcanii. These encode both guide RNAs and enzymes. Some are orthologous to previously identified genes in Archaea, Bacteria or in Saccharomyces cerevisiae, but several are original predictions. Conclusion The number of modifications in t+rRNAs in the halophilic archaeon is surprisingly low when compared with other Archaea or Bacteria, particularly the hyperthermophilic organisms. This may result from the specific lifestyle of halophiles that require high intracellular salt concentration for survival. This salt content could allow RNA to maintain its functional structural integrity with fewer modifications. We predict that the few modifications present must be particularly important for decoding, accuracy of translation or are modifications that cannot be functionally replaced by the electrostatic interactions provided by the surrounding salt-ions. This analysis also guides future experimental validation work aiming to complete the understanding of the function of RNA modifications in Archaeal translation.
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Affiliation(s)
- Henri Grosjean
- Department of Microbiology, University of Florida, Gainsville, FL 32611, Florida, USA.
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