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Makraki E, Miliara S, Pagkalos M, Kokkinidis M, Mylonas E, Fadouloglou VE. Probing the conformational changes of in vivo overexpressed cell cycle regulator 6S ncRNA. Front Mol Biosci 2023; 10:1219668. [PMID: 37555016 PMCID: PMC10406553 DOI: 10.3389/fmolb.2023.1219668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 07/05/2023] [Indexed: 08/10/2023] Open
Abstract
The non-coding 6S RNA is a master regulator of the cell cycle in bacteria which binds to the RNA polymerase-σ70 holoenzyme during the stationary phase to inhibit transcription from the primary σ factor. Inhibition is reversed upon outgrowth from the stationary phase by synthesis of small product RNA transcripts (pRNAs). 6S and its complex with a pRNA were structurally characterized using Small Angle X-ray Scattering. The 3D models of 6S and 6S:pRNA complex presented here, demonstrate that the fairly linear and extended structure of 6S undergoes a major conformational change upon binding to pRNA. In particular, 6S:pRNA complex formation is associated with a compaction of the overall 6S size and an expansion of its central domain. Our structural models are consistent with the hypothesis that the resultant particle has a shape and size incompatible with binding to RNA polymerase-σ70. Overall, by use of an optimized in vivo methodological approach, especially useful for structural studies, our study considerably improves our understanding of the structural basis of 6S regulation by offering a mechanistic glimpse of the 6S transcriptional control.
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Affiliation(s)
- Eleni Makraki
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology—Hellas (IMBB-FORTH), Heraklion, Greece
| | - Sophia Miliara
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology—Hellas (IMBB-FORTH), Heraklion, Greece
| | - Michalis Pagkalos
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology—Hellas (IMBB-FORTH), Heraklion, Greece
- Department of Biology, University of Crete, Heraklion, Greece
| | - Michael Kokkinidis
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology—Hellas (IMBB-FORTH), Heraklion, Greece
- Department of Biology, University of Crete, Heraklion, Greece
| | - Efstratios Mylonas
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology—Hellas (IMBB-FORTH), Heraklion, Greece
| | - Vasiliki E. Fadouloglou
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology—Hellas (IMBB-FORTH), Heraklion, Greece
- Department of Molecular Biology and Genetics, Democritus University of Thrace, Komotini, Greece
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Graczyk A, Radzikowska-Cieciura E, Kaczmarek R, Pawlowska R, Chworos A. Modified Nucleotides for Chemical and Enzymatic Synthesis of Therapeutic RNA. Curr Med Chem 2023; 30:1320-1347. [PMID: 36239720 DOI: 10.2174/0929867330666221014111403] [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: 03/02/2022] [Revised: 04/22/2022] [Accepted: 05/16/2022] [Indexed: 11/22/2022]
Abstract
In recent years, RNA has emerged as a medium with a broad spectrum of therapeutic potential, however, for years, a group of short RNA fragments was studied and considered therapeutic molecules. In nature, RNA plays both functions, with coding and non-coding potential. For RNA, like any other therapeutic, to be used clinically, certain barriers must be crossed. Among them, there are biocompatibility, relatively low toxicity, bioavailability, increased stability, target efficiency and low off-target effects. In the case of RNA, most of these obstacles can be overcome by incorporating modified nucleotides into its structure. This may be achieved by both, in vitro and in vivo biosynthetic methods, as well as chemical synthesis. Some advantages and disadvantages of each approach are summarized here. The wide range of nucleotide analogues has been tested for their utility as monomers for RNA synthesis. Many of them have been successfully implemented, and a lot of pre-clinical and clinical studies involving modified RNA have been carried out. Some of these medications have already been introduced into clinics. After the huge success of RNA-based vaccines that were introduced into widespread use in 2020, and the introduction to the market of some RNA-based drugs, RNA therapeutics containing modified nucleotides appear to be the future of medicine.
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Affiliation(s)
- Anna Graczyk
- Department of Bioorganic Chemistry, Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences, Sienkiewicza 112, 90-363 Lodz, Poland
| | - Ewa Radzikowska-Cieciura
- Department of Bioorganic Chemistry, Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences, Sienkiewicza 112, 90-363 Lodz, Poland
| | - Renata Kaczmarek
- Department of Bioorganic Chemistry, Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences, Sienkiewicza 112, 90-363 Lodz, Poland
| | - Roza Pawlowska
- Department of Bioorganic Chemistry, Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences, Sienkiewicza 112, 90-363 Lodz, Poland
| | - Arkadiusz Chworos
- Department of Bioorganic Chemistry, Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences, Sienkiewicza 112, 90-363 Lodz, Poland
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3
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Ling J, Fan C, Qin H, Wang M, Chen J, Wittung‐Stafshede P, Zhu TF. Mirror‐Image 5S Ribonucleoprotein Complexes. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.201914799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Jun‐Jie Ling
- School of Life SciencesTsinghua-Peking Center for Life SciencesBeijing Frontier Research Center for Biological StructureCenter for Synthetic and Systems BiologyMinistry of Education Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical BiologyMinistry of Education Key Laboratory of BioinformaticsTsinghua University Beijing 100084 China
| | - Chuyao Fan
- School of Life SciencesTsinghua-Peking Center for Life SciencesBeijing Frontier Research Center for Biological StructureCenter for Synthetic and Systems BiologyMinistry of Education Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical BiologyMinistry of Education Key Laboratory of BioinformaticsTsinghua University Beijing 100084 China
| | - Hong Qin
- School of Life SciencesTsinghua-Peking Center for Life SciencesBeijing Frontier Research Center for Biological StructureCenter for Synthetic and Systems BiologyMinistry of Education Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical BiologyMinistry of Education Key Laboratory of BioinformaticsTsinghua University Beijing 100084 China
| | - Min Wang
- School of Life SciencesTsinghua-Peking Center for Life SciencesBeijing Frontier Research Center for Biological StructureCenter for Synthetic and Systems BiologyMinistry of Education Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical BiologyMinistry of Education Key Laboratory of BioinformaticsTsinghua University Beijing 100084 China
| | - Ji Chen
- School of Life SciencesTsinghua-Peking Center for Life SciencesBeijing Frontier Research Center for Biological StructureCenter for Synthetic and Systems BiologyMinistry of Education Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical BiologyMinistry of Education Key Laboratory of BioinformaticsTsinghua University Beijing 100084 China
| | - Pernilla Wittung‐Stafshede
- Chemical Biology DivisionDepartment of Biology and Biological EngineeringChalmers University of Technology 41296 Gothenburg Sweden
| | - Ting F. Zhu
- School of Life SciencesTsinghua-Peking Center for Life SciencesBeijing Frontier Research Center for Biological StructureCenter for Synthetic and Systems BiologyMinistry of Education Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical BiologyMinistry of Education Key Laboratory of BioinformaticsTsinghua University Beijing 100084 China
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4
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Asadi-Atoi P, Barraud P, Tisne C, Kellner S. Benefits of stable isotope labeling in RNA analysis. Biol Chem 2020; 400:847-865. [PMID: 30893050 DOI: 10.1515/hsz-2018-0447] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 03/11/2019] [Indexed: 02/07/2023]
Abstract
RNAs are key players in life as they connect the genetic code (DNA) with all cellular processes dominated by proteins. They contain a variety of chemical modifications and many RNAs fold into complex structures. Here, we review recent progress in the analysis of RNA modification and structure on the basis of stable isotope labeling techniques. Mass spectrometry (MS) and nuclear magnetic resonance (NMR) spectroscopy are the key tools and many breakthrough developments were made possible by the analysis of stable isotope labeled RNA. Therefore, we discuss current stable isotope labeling techniques such as metabolic labeling, enzymatic labeling and chemical synthesis. RNA structure analysis by NMR is challenging due to two major problems that become even more salient when the size of the RNA increases, namely chemical shift overlaps and line broadening leading to complete signal loss. Several isotope labeling strategies have been developed to provide solutions to these major issues, such as deuteration, segmental isotope labeling or site-specific labeling. Quantification of modified nucleosides in RNA by MS is only possible through the application of stable isotope labeled internal standards. With nucleic acid isotope labeling coupled mass spectrometry (NAIL-MS), it is now possible to analyze the dynamic processes of post-transcriptional RNA modification and demodification. The trend, in both NMR and MS RNA analytics, is without doubt shifting from the analysis of snapshot moments towards the development and application of tools capable of analyzing the dynamics of RNA structure and modification profiles.
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Affiliation(s)
- Paria Asadi-Atoi
- Department of Chemistry, Ludwig-Maximilians-University Munich, Butenandtstr. 5-13, D-81377 Munich, Germany
| | - Pierre Barraud
- Institut de Biologie Physico-Chimique (IBPC), UMR 8261, CNRS, Université Paris Diderot, 13 rue Pierre et Marie Curie, F-75005 Paris, France
| | - Carine Tisne
- Institut de Biologie Physico-Chimique (IBPC), UMR 8261, CNRS, Université Paris Diderot, 13 rue Pierre et Marie Curie, F-75005 Paris, France
| | - Stefanie Kellner
- Department of Chemistry, Ludwig-Maximilians-University Munich, Butenandtstr. 5-13, D-81377 Munich, Germany
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5
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Ling JJ, Fan C, Qin H, Wang M, Chen J, Wittung-Stafshede P, Zhu TF. Mirror-Image 5S Ribonucleoprotein Complexes. Angew Chem Int Ed Engl 2020; 59:3724-3731. [PMID: 31841243 PMCID: PMC7217020 DOI: 10.1002/anie.201914799] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Indexed: 12/01/2022]
Abstract
After realizing mirror‐image genetic replication, transcription, and reverse transcription, the biggest challenge in establishing a mirror‐image version of the central dogma is to build a mirror‐image ribosome‐based translation machine. Here, we chemically synthesized the natural and mirror‐image versions of three ribosomal proteins (L5, L18, and L25) in the large subunit of the Escherichia coli ribosome with post‐translational modifications. We show that the synthetic mirror‐image proteins can fold in vitro despite limited efficiency and assemble with enzymatically transcribed mirror‐image 5S ribosomal RNA into ribonucleoprotein complexes. In addition, the RNA–protein interactions are chiral‐specific in that the mirror‐image ribosomal proteins do not bind with natural 5S ribosomal RNA and vice versa. The synthesis and assembly of mirror‐image 5S ribonucleoprotein complexes are important steps towards building a functional mirror‐image ribosome.
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Affiliation(s)
- Jun-Jie Ling
- School of Life Sciences, Tsinghua-Peking Center for Life Sciences, Beijing Frontier Research Center for Biological Structure, Center for Synthetic and Systems Biology, Ministry of Education Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology, Ministry of Education Key Laboratory of Bioinformatics, Tsinghua University, Beijing, 100084, China
| | - Chuyao Fan
- School of Life Sciences, Tsinghua-Peking Center for Life Sciences, Beijing Frontier Research Center for Biological Structure, Center for Synthetic and Systems Biology, Ministry of Education Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology, Ministry of Education Key Laboratory of Bioinformatics, Tsinghua University, Beijing, 100084, China
| | - Hong Qin
- School of Life Sciences, Tsinghua-Peking Center for Life Sciences, Beijing Frontier Research Center for Biological Structure, Center for Synthetic and Systems Biology, Ministry of Education Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology, Ministry of Education Key Laboratory of Bioinformatics, Tsinghua University, Beijing, 100084, China
| | - Min Wang
- School of Life Sciences, Tsinghua-Peking Center for Life Sciences, Beijing Frontier Research Center for Biological Structure, Center for Synthetic and Systems Biology, Ministry of Education Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology, Ministry of Education Key Laboratory of Bioinformatics, Tsinghua University, Beijing, 100084, China
| | - Ji Chen
- School of Life Sciences, Tsinghua-Peking Center for Life Sciences, Beijing Frontier Research Center for Biological Structure, Center for Synthetic and Systems Biology, Ministry of Education Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology, Ministry of Education Key Laboratory of Bioinformatics, Tsinghua University, Beijing, 100084, China
| | - Pernilla Wittung-Stafshede
- Chemical Biology Division, Department of Biology and Biological Engineering, Chalmers University of Technology, 41296, Gothenburg, Sweden
| | - Ting F Zhu
- School of Life Sciences, Tsinghua-Peking Center for Life Sciences, Beijing Frontier Research Center for Biological Structure, Center for Synthetic and Systems Biology, Ministry of Education Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology, Ministry of Education Key Laboratory of Bioinformatics, Tsinghua University, Beijing, 100084, China
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6
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Nelissen FHT, Leunissen EHP, van de Laar L, Tessari M, Heus HA, Wijmenga SS. Fast production of homogeneous recombinant RNA--towards large-scale production of RNA. Nucleic Acids Res 2012; 40:e102. [PMID: 22457065 PMCID: PMC3401473 DOI: 10.1093/nar/gks292] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
In the past decades, RNA molecules have emerged as important players in numerous cellular processes. To understand these processes at the molecular and atomic level, large amounts of homogeneous RNA are required for structural, biochemical and pharmacological investigations. Such RNAs are generally obtained from laborious and costly in vitro transcriptions or chemical synthesis. In 2007, a recombinant RNA technology has been described for the constitutive production of large amounts of recombinant RNA in Escherichia coli using a tRNA-scaffold approach. We demonstrate a general applicable extension to the described approach by introducing the following improvements: (i) enhanced transcription of large recombinant RNAs by T7 RNA polymerase (high transcription rates, versatile), (ii) efficient and facile excision of the RNA of interest from the tRNA-scaffold by dual cis-acting hammerhead ribozyme mediated cleavage and (iii) rapid purification of the RNA of interest employing anion-exchange chromatography or affinity chromatography followed by denaturing polyacrylamide gel electrophoresis. These improvements in the existing method pave the tRNA-scaffold approach further such that any (non-)structured product RNA of a defined length can cost-efficiently be obtained in (multi-)milligram quantities without in vitro enzymatic manipulations.
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Affiliation(s)
- Frank H T Nelissen
- Department of Biophysical Chemistry, Institute for Molecules and Materials, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
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7
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Large scale expression and purification of recombinant RNA in Escherichia coli. Methods 2011; 54:267-73. [PMID: 21320602 DOI: 10.1016/j.ymeth.2011.02.007] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2010] [Revised: 12/21/2010] [Accepted: 02/09/2011] [Indexed: 11/20/2022] Open
Abstract
Stable, folded RNA are involved in many key cellular processes and can be used as tools for biological, pharmacological and/or molecular design studies. However, their widespread use has been somewhat limited by their fragile nature and by the difficulties associated with their production on a large scale, which were limited to in vitro methods. This work reviews the novel techniques recently developed that allow efficient expression of recombinant RNA in vivo in Escherichia coli. Based on the extensive data available on the genetic and metabolic mechanisms of this model organism, conditions for optimal production can be derived. Combined with a large repertoire of RNA motifs which can be assembled by recombinant DNA techniques, this opens the way to the modular design of RNA molecules with novel properties.
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8
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Kauffmann AD, Campagna RJ, Bartels CB, Childs-Disney JL. Improvement of RNA secondary structure prediction using RNase H cleavage and randomized oligonucleotides. Nucleic Acids Res 2009; 37:e121. [PMID: 19596816 PMCID: PMC2764423 DOI: 10.1093/nar/gkp587] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
RNA secondary structure prediction using free energy minimization is one method to gain an approximation of structure. Constraints generated by enzymatic mapping or chemical modification can improve the accuracy of secondary structure prediction. We report a facile method that identifies single-stranded regions in RNA using short, randomized DNA oligonucleotides and RNase H cleavage. These regions are then used as constraints in secondary structure prediction. This method was used to improve the secondary structure prediction of Escherichia coli 5S rRNA. The lowest free energy structure without constraints has only 27% of the base pairs present in the phylogenetic structure. The addition of constraints from RNase H cleavage improves the prediction to 100% of base pairs. The same method was used to generate secondary structure constraints for yeast tRNAPhe, which is accurately predicted in the absence of constraints (95%). Although RNase H mapping does not improve secondary structure prediction, it does eliminate all other suboptimal structures predicted within 10% of the lowest free energy structure. The method is advantageous over other single-stranded nucleases since RNase H is functional in physiological conditions. Moreover, it can be used for any RNA to identify accessible binding sites for oligonucleotides or small molecules.
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Affiliation(s)
- Andrew D Kauffmann
- Department of Chemistry and Biochemistry, Canisius College, 2001 Main St., Buffalo, NY 14208, USA
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9
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Ponchon L, Dardel F. Recombinant RNA technology: the tRNA scaffold. Nat Methods 2007; 4:571-6. [PMID: 17558412 DOI: 10.1038/nmeth1058] [Citation(s) in RCA: 175] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2007] [Accepted: 05/08/2007] [Indexed: 11/09/2022]
Abstract
RNA has emerged as a major player in most cellular processes. Understanding these processes at the molecular level requires homogeneous RNA samples for structural, biochemical and pharmacological studies. So far, this has been a bottleneck, as the only methods for producing such pure RNA have been in vitro syntheses. Here we describe a generic approach for expressing and purifying structured RNA in Escherichia coli, using tools that parallel those available for recombinant proteins. Our system is based on a camouflage strategy, the 'tRNA scaffold', in which the recombinant RNA is disguised as a natural RNA and thus hijacks the host machinery, escaping cellular RNases. This opens the way to large-scale structural and molecular investigations of RNA function.
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Affiliation(s)
- Luc Ponchon
- Cristallographie & RMN Biologiques, Université Paris Descartes, CNRS, 4 avenue de l'Observatoire, 75006, Paris, France
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10
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Kierzek E, Kierzek R, Turner DH, Catrina IE. Facilitating RNA structure prediction with microarrays. Biochemistry 2006; 45:581-93. [PMID: 16401087 PMCID: PMC4070881 DOI: 10.1021/bi051409+] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Determining RNA secondary structure is important for understanding structure-function relationships and identifying potential drug targets. This paper reports the use of microarrays with heptamer 2'-O-methyl oligoribonucleotides to probe the secondary structure of an RNA and thereby improve the prediction of that secondary structure. When experimental constraints from hybridization results are added to a free-energy minimization algorithm, the prediction of the secondary structure of Escherichia coli 5S rRNA improves from 27 to 92% of the known canonical base pairs. Optimization of buffer conditions for hybridization and application of 2'-O-methyl-2-thiouridine to enhance binding and improve discrimination between AU and GU pairs are also described. The results suggest that probing RNA with oligonucleotide microarrays can facilitate determination of secondary structure.
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Affiliation(s)
| | - Ryszard Kierzek
- Institute of Bioorganic Chemistry Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznań, Poland
| | - Douglas H. Turner
- To whom correspondence should be addressed. Phone: (585) 275-3207. Fax: (585) 276-0205.
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11
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White SA, Nilges M, Huang A, Brünger AT, Moore PB. NMR analysis of helix I from the 5S RNA of Escherichia coli. Biochemistry 2002; 31:1610-21. [PMID: 1371071 DOI: 10.1021/bi00121a005] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The structure of helix I of the 5S rRNA from Escherichia coli has been determined using a nucleolytic digest fragment of the intact molecule. The fragment analyzed, which corresponds to bases (-1)-11 and 108-120 of intact 5S rRNA, contains a G-U pair and has unpaired bases at its termini. Its proton resonances were assigned by two-dimensional NMR methods, and both NOE distance and coupling constant information have been used to calculate structural models for it using the full relaxation matrix algorithm of the molecular dynamics program XPLOR. Helix I has A-type helical geometry, as expected. Its most striking departure from regular helical geometry occurs at its G-U, which stacks on the base pair to the 5' side of its G but not on the base pair to its 3' side. This stacking pattern maximizes interstrand guanine-guanine interactions and explains why the G-U in question fails to give imino proton NOE's to the base pair to 5' side of its G. These results are consistent with the crystal structures that have been obtained for wobble base pairs in tRNAPhe [Mizuno, H., & Sundaralingam, M. (1978) Nucleic Acids Res. 5, 4451-4461] and A-form DNA [Rabbinovich, D., Haran, T., Eisenstein, M., & Shakked, Z. (1988) J. Mol. Biol. 200, 151-161]. The conformations of the terminal residues of helix I, which corresponds to bases (-1)-11 and 108-120 of native 5S RNA, are less well-determined, and their sugar puckers are intermediate between C2' and C3'-endo, on average.
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Affiliation(s)
- S A White
- Department of Chemistry, Yale University, New Haven, Connecticut 06511
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12
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Dallas A, Moore PB. The loop E-loop D region of Escherichia coli 5S rRNA: the solution structure reveals an unusual loop that may be important for binding ribosomal proteins. Structure 1997; 5:1639-53. [PMID: 9438864 DOI: 10.1016/s0969-2126(97)00311-0] [Citation(s) in RCA: 100] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND 5S ribosomal RNA is the smallest rRNA. Its Watson-Crick helices were identified more than 20 years ago, but the conformations of its loops have long defied analysis. One of the three arms of 5S rRNA, residues 69-106 in Escherichia coli, contains a 14-residue internal loop called loop E. The sequence of loop E is conserved within kingdoms, and is terminated by a pyrimidine-rich loop called loop D. Loop E is the binding site for the ribosomal protein L25 in the E. coli ribosome. RESULTS The solution structure of a 42-nucleotide derivative of E. coli 5S rRNA that includes loops D and E has been determined by nuclear magnetic resonance spectroscopy. Formally, loop E is not a loop at all; it is a double helical structure that contains seven, consecutive non-Watson-Crick base pairs. The major groove of the molecule is narrowed in loop E, and an unusual array of hydrogen-bond donors and acceptors appear in its minor groove. Loop D, which on paper looks like a three-pyrimidine terminal loop closed by a GC, is better thought of as a five-base loop because its closing GC is not a normal Watson-Crick pair. The two pyrimidines on the 5'-side of the loop are stacked on each other, and tilt into the minor groove of the adjacent helix. The third pyrimidine is fully exposed to solvent. CONCLUSIONS This structure rationalizes all the biochemical and chemical protection data available for the loop E-loop D arm of intact 5S rRNA. While the molecule is double helical over its entire length, the geometry of its internal loop is highly irregular, and its irregularities may explain why the loop E-loop D arm of 5S rRNA interacts specifically with ribosomal protein L25 in E. coli.
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Affiliation(s)
- A Dallas
- Department of Chemistry, Yale University, New Haven, CT 06520-8107, USA
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13
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Correll CC, Freeborn B, Moore PB, Steitz TA. Use of chemically modified nucleotides to determine a 62-nucleotide RNA crystal structure: a survey of phosphorothioates, Br, Pt and Hg. J Biomol Struct Dyn 1997; 15:165-72. [PMID: 9399146 DOI: 10.1080/07391102.1997.10508183] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Two important challenges confronting RNA crystallographers are producing crystals and finding isomorphous heavy-atom derivatives. Non-isomorphism can be addressed by determining the phases using the multiwavelength anomalous dispersion (MAD) method. These phases can be greatly improved by combining phases from MAD experiments done on different heavy-atom derivatives. Heavy-atom derivatives can be created by chemically modifying the RNA through covalent attachment of bromine or mercury to C5 of pyrimidines or [Pt(NH3)3]2+ to N7 of guanine. While phosphorothioates can provide mercury binding sites, disorder can reduce their value for phase determination. The location of these chemical modifications is critical since crystallization of these derivatized RNAs is sensitive to heavy atom induced conformational alterations and crystal packing.
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Affiliation(s)
- C C Correll
- Howard Hughes Medical Institute, Yale University, New Haven, CT 06520-8114, USA
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14
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Dallas A, Rycyna R, Moore P. A proposal for the conformation of loop E in Escherichia coli 5S rRNA. Biochem Cell Biol 1995; 73:887-97. [PMID: 8722004 DOI: 10.1139/o95-096] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
A proposal is advanced for the conformation of the loop E region of prokaryotic 5S rRNAs based on spectroscopic data obtained from pAD3 RNA, a construct that includes helix IV, helix V, and loops D and E from Escherichia coli 5S rRNA. Even though loop E juxtaposes bases that cannot form Watson-Crick base pairs, it resembles an A-form double helix; its nucleotides relate to each other spectroscopically in a helix-like way and are in the anti conformation. The ends of loop E, which is palindromic, have the same conformation. Working in from either end towards the center of the loop, a closing GC is followed by a side-by-side GA and then by a reversed Hoogsteen AU, a pattern resembling that found at one end of eukaryotic loop E. The center of the loop consists of three nucleotide pairs, which appear to be an asymmetric GG pair, a Watson-Crick-like AG, and a GU stabilized by a single hydrogen bond.
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Affiliation(s)
- A Dallas
- Departments of Chemistry and Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520-8107, USA
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15
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16
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Kim J, Cheong C, Moore PB. Tetramerization of an RNA oligonucleotide containing a GGGG sequence. Nature 1991; 351:331-2. [PMID: 1709723 DOI: 10.1038/351331a0] [Citation(s) in RCA: 113] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Poly rG can form four-stranded helices. The Hoogsteen-paired quartets of G residues on which such structures depend are so stable that they will form in 5'-GMP solutions, provided that Na+ or K+ are present (see for example, refs 2-4). Telomeric DNA sequences, which are G-rich, adopt four-stranded antiparallel G-quartet conformations in vitro, and parallel tetramerization of G-rich sequences may be involved in meiosis. Here we show that RNAs containing short runs of Gs can also tetramerize. A 19-base oligonucleotide derived from the 5S RNA of Escherichia coli (strand III), 5'GCCGAUGGUAGUGUGGGGU3', forms a K(+)-stabilized tetrameric aggregate that depends on the G residues at its 3' end. This complex is so stable that it would be surprising if similar structures do not occur in nature.
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Affiliation(s)
- J Kim
- Department of Chemistry, Yale University, New Haven, Connecticut 06511
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17
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Zhang P, Moore PB. An NMR study of the helix V-loop E region of the 5S RNA from Escherichia coli. Biochemistry 1989; 28:4607-15. [PMID: 2669961 DOI: 10.1021/bi00437a015] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Experiments are described that complete the assignment of the imino proton NMR spectrum of the fragment 1 domain from the 5S RNA of Escherichia coli. Most of the new assignments fall in the helix V-loop E portion of the molecule (bases 70-78 and 98-106), the region most sensitive to the binding of ribosomal protein L25. The spectroscopic data are incompatible with the standard, phylogenetically derived model for 5S RNA, which makes all the base pairs possible in loop E with the sequences aligned in parallel (C70-G106, C71-G105, etc.) [see Delihas et al. (1984) Prog. Nucleic Acid Res. Mol. Biol. 31, 161-190]. Furthermore, the alternative loop E model proposed for spinach chloroplast 5S RNA by Romby et al. [(1988) Biochemistry 27, 4721-4730] does not apply to the closely homologous 5S RNA from E. coli. The 5S RNAs from E. coli and spinach chloroplasts do not have the same secondary structures in solution despite their strong sequence homologies, and neither appears to conform to the standard model for 5S RNA in the loop E region.
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Affiliation(s)
- P Zhang
- Department of Chemistry, Yale University, New Haven, Connecticut 05611
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