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Yan M, Wang Y, Hu Y, Feng Y, Dai C, Wu J, Wu D, Zhang F, Zhai Q. A High-Throughput Quantitative Approach Reveals More Small RNA Modifications in Mouse Liver and Their Correlation with Diabetes. Anal Chem 2013; 85:12173-81. [DOI: 10.1021/ac4036026] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- Menghong Yan
- Key Laboratory
of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai
Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Yuangao Wang
- Key Laboratory
of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai
Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Yanan Hu
- Key Laboratory
of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai
Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Yan Feng
- Key Laboratory
of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai
Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Changgui Dai
- Key Laboratory
of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai
Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Jingxia Wu
- Key Laboratory
of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai
Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Dongmei Wu
- Key Laboratory
of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai
Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Fang Zhang
- Key Laboratory
of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai
Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Qiwei Zhai
- Key Laboratory
of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai
Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200031, China
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2
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Kouvela EC, Gerbanas GV, Xaplanteri MA, Petropoulos AD, Dinos GP, Kalpaxis DL. Changes in the conformation of 5S rRNA cause alterations in principal functions of the ribosomal nanomachine. Nucleic Acids Res 2007; 35:5108-19. [PMID: 17652323 PMCID: PMC1976436 DOI: 10.1093/nar/gkm546] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
5S rRNA is an integral component of the large ribosomal subunit in virtually all living organisms. Polyamine binding to 5S rRNA was investigated by cross-linking of N1-azidobenzamidino (ABA)-spermine to naked 5S rRNA or 50S ribosomal subunits and whole ribosomes from Escherichia coli cells. ABA-spermine cross-linking sites were kinetically measured and their positions in 5S rRNA were localized by primer extension analysis. Helices III and V, and loops A, C, D and E in naked 5S rRNA were found to be preferred polyamine binding sites. When 50S ribosomal subunits or poly(U)-programmed 70S ribosomes bearing tRNAPhe at the E-site and AcPhe-tRNA at the P-site were targeted, the susceptibility of 5S rRNA to ABA-spermine was greatly reduced. Regardless of 5S rRNA assembly status, binding of spermine induced significant changes in the 5S rRNA conformation; loop A adopted an apparent ‘loosening’ of its structure, while loops C, D, E and helices III and V achieved a more compact folding. Poly(U)-programmed 70S ribosomes possessing 5S rRNA cross-linked with spermine were more efficient than control ribosomes in tRNA binding, peptidyl transferase activity and translocation. Our results support the notion that 5S rRNA serves as a signal transducer between regions of 23S rRNA responsible for principal ribosomal functions.
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3
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Schäferkordt J, Wagner R. Effects of base change mutations within an Escherichia coli ribosomal RNA leader region on rRNA maturation and ribosome formation. Nucleic Acids Res 2001; 29:3394-403. [PMID: 11504877 PMCID: PMC55841 DOI: 10.1093/nar/29.16.3394] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The effects of base change mutations in a highly conserved sequence (boxC) within the leader of bacterial ribosomal RNAs (rRNAs) was studied. The boxC sequence preceding the 16S rRNA structural gene constitutes part of the RNase III processing site, one of the first cleavage sites on the pathway to mature 16S rRNA. Moreover, rRNA leader sequences facilitate correct 16S rRNA folding, thereby assisting ribosomal subunit formation. Mutations in boxC cause cold sensitivity and result in 16S rRNA and 30S subunit deficiency. Strains in which all rRNA operons are replaced by mutant transcription units are viable. Thermodynamic studies by temperature gradient gel electrophoresis reveal that mutant transcripts have a different, less ordered structure. In addition, RNA secondary structure differences between mutant and wild-type transcripts were determined by chemical and enzymatic probing. Differences are found in the leader RNA sequence itself but also in structurally important regions of the mature 16S rRNA. A minor fraction of the rRNA transcripts from mutant operons is not processed by RNase III, resulting in a significantly extended precursor half-life compared to the wild-type. The boxC mutations also give rise to a new aberrant degradation product of 16S rRNA. This intermediate cannot be detected in strains lacking RNase III. Together the results indicate that the boxC sequence, although important for RNase III processing, is likely to serve additional functions by facilitating correct formation of the mature 16S rRNA structure. They also suggest that quality control steps are acting during ribosome biogenesis.
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MESH Headings
- Bacterial Proteins/chemistry
- Bacterial Proteins/genetics
- Bacterial Proteins/metabolism
- Base Sequence
- Cold Temperature
- Conserved Sequence/genetics
- Endoribonucleases/metabolism
- Escherichia coli/genetics
- Escherichia coli/growth & development
- Escherichia coli/metabolism
- Escherichia coli Proteins
- Half-Life
- Molecular Sequence Data
- Mutation/genetics
- Nuclease Protection Assays
- Nucleic Acid Conformation
- Operon/genetics
- Phenotype
- Protein Subunits
- RNA Processing, Post-Transcriptional
- RNA Stability
- RNA, Bacterial/chemistry
- RNA, Bacterial/genetics
- RNA, Bacterial/metabolism
- RNA, Ribosomal, 16S/chemistry
- RNA, Ribosomal, 16S/genetics
- RNA, Ribosomal, 16S/metabolism
- Ribonuclease III
- Ribosomes/chemistry
- Ribosomes/genetics
- Ribosomes/metabolism
- Sequence Deletion/genetics
- Temperature
- Thermodynamics
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Affiliation(s)
- J Schäferkordt
- Institut für Physikalische Biologie, Heinrich-Heine-Universität Düsseldorf, Universitätsstrasse 1, D-40225 Düsseldorf, Germany
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4
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Sergiev P, Dokudovskaya S, Romanova E, Topin A, Bogdanov A, Brimacombe R, Dontsova O. The environment of 5S rRNA in the ribosome: cross-links to the GTPase-associated area of 23S rRNA. Nucleic Acids Res 1998; 26:2519-25. [PMID: 9592132 PMCID: PMC147597 DOI: 10.1093/nar/26.11.2519] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Two photoreactive diazirine derivatives of uridine were used to study contacts between 5S rRNA and 23 rRNA in situ in Escherichia coli ribosomes. 2'-Amino-2'-deoxy-uridine or 5-methyleneaminouridine were introduced into 5S rRNA by T7 transcription. After incorporation of these uridine analogues into the transcript their amino groups were modified with 4-[3-(trifluoromethyl)-3 H -diazirin-3-yl]benzyl isothiocyanate or the N -hydroxysuccinimide ester of 4-[3-(trifluoromethyl)-3 H -diazirin-3-yl]benzoic acid respectively. 5S rRNA carrying the photoreactive diazirine groups (referred to as the 2'-aminoribose derivative and the 5-methyleneamino derivative respectively) was reconstituted into 50S subunits or 70S ribosomes. After mild UV irradiation cross-links formed to 23S rRNA were analysed by standard procedures. All of the observed cross-links involved residue U89 of the 5S rRNA. Three nucleotides of 23S rRNA were cross-linked to this residue with the 5-methyleneamino derivative, namely U958, G1022 and G1138. With the 2'-aminoribose derivative a single cross-link was found, to U958. The significance of these cross-links for our understanding of the structure and function of 5S rRNA and its environment in the ribosome are discussed.
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Affiliation(s)
- P Sergiev
- A. N. Belozersky Institute of Physico-Chemical Biology and Department of Chemistry, Moscow State University, Moscow 119899, Russia
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5
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Abstract
The tertiary structure of nucleic acid hairpins was elucidated by means of the accessibility of the single-strand-specific nuclease from mung bean. This molecular probe has proven especially useful in determining details of the structural arrangement of the nucleotides within a loop. In this study 3'-labeling is introduced to complement previously used 5'-labeling in order to assess and to exclude possible artifacts of the method. Both labeling procedures result in mutually consistent cleavage patterns. Therefore, methodological artifacts can be excluded and the potential of the nuclease as structural probe is increased. DNA hairpins with five and six membered loops reveal an asymmetric loop structure with a sharp bend of the phosphate-ribose backbone between the second and third nucleotide on the 3'-side of a loop. These hairpin structures differ from smaller loops with 3 or 4 members, which reveal this type of bend between the first and second 3' nucleotide, and resemble with respect to the asymmetry anticodon loops of tRNA.
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Affiliation(s)
- U Baumann
- NASA Ames Research Center, Planet, Biology Branch, Moffett Field, CA, USA
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6
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Pardon B, Wagner R. The Escherichia coli ribosomal RNA leader nut region interacts specifically with mature 16S RNA. Nucleic Acids Res 1995; 23:932-41. [PMID: 7731806 PMCID: PMC306788 DOI: 10.1093/nar/23.6.932] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
All ribosomal RNAs are preceded by leader sequences not present in the final ribosome particles. The highly conserved leader sequences of bacterial rRNAs are known to be important for the folding and assembly of functional ribosomes. Very likely transient binding of the leader to mature parts of the 16S RNA occurs during transcription. To better understand the mechanistic details of these functions we have performed a secondary structural analysis of E. coli ribosomal RNA leader transcripts by chemical modification and enzymatic hydrolysis studies. The data were combined with results from thermodynamic stability calculations to yield a generalized structural model. The same secondary structure of the leader core, comprising the nut-like sequences up to the mature 5' end of the 16S RNA, was deduced, irrespective if transcripts started at promoter P1 or 120 nucleotides downstream at P2. Employing gelshift and cross-linking studies we were able to demonstrate that a part of the leader core, namely the nut-like sequence elements bind directly to specific regions within the mature 16S RNA. The sites of RNA-RNA cross-linking could be localized by sequencing. They map in the 16S RNA 5' domain at nucleotide positions G27 to G42, C48, G68, G117 and G126. The results may explain the recently observed scaffolding function of the leader RNA during ribosome biogenesis.
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Affiliation(s)
- B Pardon
- Institut für Physikalische Biologie, Heinrich-Heine-Universität Düsseldorf, Germany
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7
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Pardon B, Thelen L, Wagner R. The Escherichia coli ribosomal RNA leader: a structural and functional investigation. BIOLOGICAL CHEMISTRY HOPPE-SEYLER 1994; 375:11-20. [PMID: 7516168 DOI: 10.1515/bchm3.1994.375.1.11] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The structure of the E. coli ribosomal RNA leader was analyzed by treatment with single and double strand specific ribonucleases and by chemical modification. The experimentally derived data together with secondary structure calculations according to minimum free energy was used to construct a secondary structure model. The binding of purified Nus proteins to the ribosomal leader RNA was further tested. Contrary to the recently reported interactions of NusB and NusE with a nut RNA sequence we obtained evidence that the presence of NusA and NusE resulted in protection against hydroxyl radical reaction of the leader nut elements boxA, boxB and boxC. The possible significance of this interaction is discussed. In the second part of the study we analyzed effects of leader mutations, which are known to affect cell growth, on the activity of ribosomes in vivo. A system was used able to distinguish the proportion of ribosomes assembled from rRNA of chromosomal origin (wild type) and plasmid origin (mutant). It turned out that the amount of 16S RNA transcribed from genes with point mutations in the leader region decreased if ribosomal pools with different translational activities were compared. High amounts of transcripts from mutant operons were present in the free ribosomal RNA and the free 30S fractions. Significantly less 16S RNA transcripts from the mutated genes were detected in the functionally active and homogeneous 70S tight couple preparations, and even less in the polysome fraction involved in active translation. The results allow a better understanding of the function of rRNA leader sequences in structure formation and correct ribosome biogenesis.
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Affiliation(s)
- B Pardon
- Institut für Physikalische Biologie, Heinrich-Heine-Universität Düsseldorf, Germany
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8
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Ciesiołlka J, Lorenz S, Erdmann VA. Different conformational forms of Escherichia coli and rat liver 5S rRNA revealed by Pb(II)-induced hydrolysis. EUROPEAN JOURNAL OF BIOCHEMISTRY 1992; 204:583-9. [PMID: 1541274 DOI: 10.1111/j.1432-1033.1992.tb16671.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Different stable forms of Escherichia coli and rat liver 5S rRNA have been probed by Pb(II)-induced hydrolysis. In the native A forms of 5S rRNA, Pb2+ reveal single-stranded RNA stretches and regions of increased conformational flexibility or distorted by the presence of bulged nucleotides. Hydrolysis of urea/EDTA-treated E. coli 5S rRNA (B form) shows the presence of two strong helical domains; helix A retained from the A form and a helix composed of RNA regions G33-C42 and G79-C88. Other RNA regions resistant to hydrolysis may be involved in alternative base pairing, causing conformational heterogeneity of that form. Pb(II)-induced hydrolysis distinguishes two different forms of rat liver 5S rRNA; the native A form and the form obtained by renaturation of 5S rRNA in the presence of EDTA. Pb(II)-hydrolysis data suggest that both forms are highly structured. In the latter form, the orientation of the bulged C66 is changed with respect to helix B. At the same time, a new helical segment is possibly formed, composed of nucleotides from helix C and loop c on one side and from helix E and loop d' on the other.
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Affiliation(s)
- J Ciesiołlka
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznań
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9
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Schmidt S, Niemann A, Krynetskaya NF, Oretskaya TS, Metelev VG, Suchomlinov VV, Shabarova ZA, Cech D. The use of oligonucleotide probes containing 2′-deoxy-2′-fluoronucleosides for regiospecific cleavage of RNA by RNase H from Escherichia coli. ACTA ACUST UNITED AC 1992; 1130:41-6. [PMID: 1371935 DOI: 10.1016/0167-4781(92)90459-d] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Protected 2'-deoxy-2'-fluorouridine and 2'-deoxy-2'-fluorocytidine suitable for incorporation into oligonucleotides via the phosphoramidite approach have been prepared. Five modified and two unmodified oligonucleotides have been synthesized to investigate the regiospecific cleavage of a 5S RNA from Escherichia coli by RNase H. In order to show whether the modified oligonucleotides are able to hybridize with the RNA the physico-chemical properties (melting curves, CD spectra) of analogous DNA/oligodeoxyribonucleotide duplexes have been examined. The modified oligonucleotides are shown to form stable duplexes with a DNA-matrix which exist in an A-like form. Two of the modified probes containing four 2'-deoxy-2'-fluorocytidines or two 2'-deoxy-2'-fluorouridines direct the splitting by RNase H of only one phosphodiester bond of the RNA.
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Affiliation(s)
- S Schmidt
- Humboldt University, Institute of Bioorganic Chemistry, Berlin, Germany
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10
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Lorenz S, Hartmann RK, Schultze S, Ulbrich N, Erdmann VA. Structural analysis of prokaryotic and eukaryotic 5S rRNAs by RNase H. Biochimie 1989; 71:1185-91. [PMID: 2561346 DOI: 10.1016/0300-9084(89)90022-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The availabilities of single-stranded 5S rRNA regions c, d and d' for base pairing interactions were analyzed by using synthetic DNA oligomers. Hybrid formation was detected by the endonucleolytical mode of the RNA-DNA specific action of RNase H. Provided that the hybrid interaction involved 6 successive base pairs, 5S rRNA loop c nucleotides 42-47 displayed accessibility in Escherichia coli, Bacillus stearothermophilus and Thermus thermophilus 5S rRNAs as well as in eukaryotic 5S rRNAs from Saccharomyces carlsbergensis, Rattus rattus and Equisetum arvense. Investigating eubacterial 5S rRNA regions d and d' (nucleotides 71-76 and 99-105, respectively), susceptibility was observed in E. coli 5S rRNA which, however, decreases in B. stearothermophilus and even more so in T. thermophilus 5S rRNA. For additional evaluation of the data obtained by RNase H cleavage, association constants of the hexanucleotides were determined by equilibrium dialysis at 4 degrees C for B. stearothermophilus 5S rRNA. The results obtained reveal that nucleotides 36-41 of B. stearothermophilus 5S rRNA are inaccessible for Watson-Crick interaction, which suggests that this part of loop c is in a structurally constrained configuration, or buried in the tertiary structure or involved in tertiary interactions.
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Affiliation(s)
- S Lorenz
- Freic Universität Berlin, Institut für Biochemie, FRG
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11
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Romby P, Westhof E, Toukifimpa R, Mache R, Ebel JP, Ehresmann C, Ehresmann B. Higher order structure of chloroplastic 5S ribosomal RNA from spinach. Biochemistry 1988; 27:4721-30. [PMID: 3167011 DOI: 10.1021/bi00413a021] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The secondary and tertiary structure of chloroplastic 5S ribosomal RNA from spinach was investigated by the use of several chemical and enzymatic structure probes. The four bases were monitored at one of their Watson-Crick base-pairing positions with dimethyl sulfate [at A(N1) and C(N3)] and with 1-cyclohexyl-3-(2-morpholinoethyl)carbodiimide metho-p-toluenesulfonate [at G(N1) and U(N3)]. Position N7 of purines was probed with diethyl pyrocarbonate (adenines) and with dimethyl sulfate (guanines). Ethylnitrosourea was used to probe phosphate involved in tertiary interaction or in cation coordination. In order to estimate the degree of stability of helices, the various chemical reagents were employed under "native" conditions (300 mM KCl and 20 mM magnesium at 37 degrees C), under "semidenaturing" conditions [1 mM ethylenediaminetetraacetic acid (EDTA) at 37 degrees C], and under denaturing conditions (1 mM EDTA at 90 degrees C). Unstructured regions were also tested with single-strand-specific nucleases T1, U2, and S1 and double-stranded or stacked regions with RNase V1 from cobra Naja naja oxiana venom. The results confirm the existence of the five helices and the two external loops proposed in the consensus model of 5S rRNA. However, the regions depicted as unpaired internal loops appear to be folded into a more complex conformation. A three-dimensional model derived from the present data and graphic modeling for a region encompassing helix IV, helix V, loop D, and loop E (nucleotides 70-110) is proposed. Nucleotides in the so-called loop E (73-79/100-106) display unusual features: Noncanonical base pairs (A-A and A-G) are formed, and three nucleotides (C75, U78, and U105) are bulging out. This region adopts an unwound and extended conformation that can be well suited for tertiary interactions or for protein binding. Several bases and phosphates candidate for the tertiary folding of the RNA were also identified.
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Affiliation(s)
- P Romby
- Laboratoire de Biochimie, Institut de Biologie Moléculaire et Cellulaire du CNRS, Strasbourg, France
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12
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Romaniuk PJ, de Stevenson IL, Ehresmann C, Romby P, Ehresmann B. A comparison of the solution structures and conformational properties of the somatic and oocyte 5S rRNAs of Xenopus laevis. Nucleic Acids Res 1988; 16:2295-312. [PMID: 3357778 PMCID: PMC338217 DOI: 10.1093/nar/16.5.2295] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The secondary and tertiary structures of Xenopus oocyte and somatic 5S rRNAs were investigated using chemical and enzymatic probes. The accessibility of both RNAs towards single-strand specific nucleases (T1, T2, A and S1) and a helix-specific ribonuclease from cobra venom (RNase V1) was determined. The reactivity of nucleobase N7, N3 and N1 positions towards chemical probes was investigated under native (5 mM MgCl2, 100 mM KCl, 20 degrees C) and semi-denaturing (1 mM EDTA, 20 degrees C) conditions. Ethylnitrosourea was used to identify phosphates not reactive towards alkylation under native conditions. The results obtained confirm the presence of the five helical stems predicted by the consensus secondary structure model of 5S rRNA. The chemical reactivity data indicate that loops C and D are involved in a number of tertiary interactions, and loop E folds into an unusual secondary structure. A comparison of the data obtained for the two types of Xenopus 5S rRNA indicates that the conformations of the oocyte and somatic 5S rRNAs are very similar. However, the data obtained with nucleases under native conditions, and chemical probes under semi-denaturing conditions, reveal that helices III and IV in the somatic 5S rRNA are less stable than the same structures in oocyte 5S rRNA. Using chimeric 5S rRNAs, it was possible to demonstrate that the relative resistance of oocyte 5S rRNA to partial denaturation in 4 M urea is conferred by the five oocyte-specific nucleotide substitutions in loop B/helix III. In contrast, the superior stability of oocyte 5S rRNA in the presence of EDTA is related to a single C substitution at position 79.
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Affiliation(s)
- P J Romaniuk
- Department of Biochemistry and Microbiology, University of Victoria, British Columbia, Canada
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14
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Romby P, Moras D, Dumas P, Ebel JP, Giegé R. Comparison of the tertiary structure of yeast tRNA(Asp) and tRNA(Phe) in solution. Chemical modification study of the bases. J Mol Biol 1987; 195:193-204. [PMID: 3309332 DOI: 10.1016/0022-2836(87)90336-6] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
A comparative study of the solution structures of yeast tRNA(Asp) and tRNA(Phe) was undertaken with chemical reagents as structural probes. The reactivity of N-7 positions in guanine and adenine residues was assayed with dimethylsulphate and diethyl-pyrocarbonate, respectively, and that of the N-3 position in cytosine residues with dimethylsulphate. Experiments involved statistical modifications of end-labelled tRNAs, followed by splitting at modified positions. The resulting end-labelled oligonucleotides were resolved on polyacrylamide sequencing gels and analysed by autoradiography. Three different experimental conditions were used to follow the progressive denaturation of the two tRNAs. Experiments were done in parallel on tRNA(Asp) and tRNA(Phe) to enable comparison between the two solution structures and to correlate the results with the crystalline conformations of both molecules. Structural differences were detected for G4, G45, G71 and A21: G4 and A21 are reactive in tRNA(Asp) and protected in tRNA(Phe), while G45 and G71 are protected in tRNA(Asp) and reactive in tRNA(Phe). For the N-7 atom of A21, the different reactivity is correlated with the variable variable loop structures in the two tRNAs; in the case of G45 the results are explained by a different stacking of A9 between G45 and residue 46. For G4 and G71, the differential reactivities are linked to a different stacking in both tRNAs. This observation is of general significance for helical stems. If the previous results could be fully explained by the crystal structures, unexpected similarities in solution were found for N-3 alkylation of C56 in the T-loop, which according to crystallography should be reactive in tRNA(Asp). The apparent discrepancy is due to conformational differences between crystalline and solution tRNA(Asp) at the level of the D and T-loop contacts, linked to long-distance effects induced by the quasi-self-complementary anticodon GUC, which favour duplex formation within the crystal, contrarily to solution conditions where the tRNA is essentially in its free state.
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Affiliation(s)
- P Romby
- Institut de Biologie Moléculaire et Cellulaire, Centre de le Recherche Scientifique, Strasbourg, France
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15
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Lorenz S, Hartmann RK, Piel N, Ulbrich N, Erdmann VA. Structural analysis of 5S rRNA, 5S rRNA-protein complexes and ribosomes employing RNase H and d(GTTCGG). EUROPEAN JOURNAL OF BIOCHEMISTRY 1987; 163:239-46. [PMID: 2434327 DOI: 10.1111/j.1432-1033.1987.tb10793.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The hybridization of d(GTTCGG) to eubacterial 5S rRNAs, 5S rRNA-protein complexes, 70S ribosomes and 50S and 30S ribosomal subunits was investigated. This oligonucleotide, which may be considered to be an analogue of the T psi CG loop of tRNAs, was chosen in order to investigate a possible interaction between tRNAs with ribosomal components during protein synthesis. The hybridization was analysed by RNase H hydrolysis studies and, in the case of the ribosomes and ribosomal subunits, in addition with the radioactively labelled oligodeoxyribonucleotide in binding studies. The results obtained lead to the conclusion that nucleotides in loop c, i.e. positions 42-47, are available for oligonucleotide interaction in free Escherichia coli and Bacillus stearothermophilus 5S rRNAs and not available in the corresponding 5S rRNA-protein complexes. The 70S ribosomes and ribosomal subunits did not interact with the oligonucleotide. Under the assumption that d(GTTCGG) is an analogue of the T psi CG loop of tRNAs and in view of the results obtained, we conclude that in the unprogrammed ribosomes the T psi CG loop of tRNAs does not interact via standard Watson-Crick base pairs with the ribosomal 5S, 16S or 23S RNAs.
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16
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Abstract
Chemical modification and limited enzymatic hydrolysis on isolated E. coli 5S RNA have provided informations on the secondary- and tertiary structure compatible with pseudoknotted structures for the A- and B-conformers of the molecule. Changes in the accessibility and reactivity of nucleotides in loop C and at the stem of helix IV in two different 5S RNA conformers are highly suggestive for interactions between bases C35 to C37 with G105 to G107 for the A-form and C38 to U40 and A94 to G96 with additional interactions of C35, C37 with G98 and G100 for the B-form. In both cases the molecules are folded forming pseudoknots and two quasi--continuous double stranded helices with coaxial stacking. The two structures are in perfect agreement with the biochemical data concerning the stability of the molecule and the chemical reactivities of individual nucleotides of the 5S RNA A- and B-conformers.
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17
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Meier N, Göringer HU, Kleuvers B, Scheibe U, Eberle J, Szymkowiak C, Zacharias M, Wagner R. The importance of individual nucleotides for the structure and function of rRNA molecules in E. coli. A mutagenesis study. FEBS Lett 1986; 204:89-95. [PMID: 3527745 DOI: 10.1016/0014-5793(86)81392-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Methods of in vitro mutagenesis were employed to determine the importance of individual nucleotides within the ribosomal RNAs for the structure and function of E. coli ribosomes. A series of defined nucleotides in the genes for the 5 S and 16 S RNA were altered by transition and transversion mutations using either oligonucleotide-directed or bisulfite-catalyzed mutation procedures. Plasmids harbouring the mutated rRNA genes were expressed and the ribosomes containing such altered RNAs were investigated for impairments in RNA-protein interaction assembly and mRNA-coded tRNA binding.
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18
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19
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Pieler T, Digweed M, Erdmann VA. RNA structural dynamics: pre-melting and melting transitions in E. coli 5S rRNA. J Biomol Struct Dyn 1985; 3:495-514. [PMID: 3917034 DOI: 10.1080/07391102.1985.10508437] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The temperature dependent transition from duplex to a single strand in E. coli 5S ribosomal RNA is a multistep process, and it involves intermediate states. We have analyzed these structural dynamics by chemical modification of cytidines and by single strand specific nuclease digestions. This combined approach led to the characterization of premelting and melting transitions within individual structural segments of the native macromolecule, which we feel may find general application to the structure of biological polyribonucleotides: 1) G-C base pairs at the termini of helices are relatively unstable and they readily undergo premelting transition. 2) Internal G-U/A-U rich stretches of helices exhibit dynamic premelting properties. 3) Hairpin loops have a relatively stronger destabilizing effect than internal loops. 4) Bulge loops destabilize the neighbouring base pairs. 5) Melting of helical segments occurs starting from the destabilizing structures listed above, preferentially from the helix termini. E. coli 5S rRNA has been shown to adopt different conformations. The presence of urea leads to induction of enhancement in the sensitivity for nuclease S1 at several nucleotide positions. The possibility of structural rearrangements will be discussed.
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Affiliation(s)
- T Pieler
- Institut für Biochemie, Freie Universität Berlin, FRG
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Szymkowiak C, Wagner R. Analysis of a sequence region of 5S RNA from E. coli cross-linked in situ to the ribosomal protein L25. Nucleic Acids Res 1985; 13:3953-68. [PMID: 3892485 PMCID: PMC341289 DOI: 10.1093/nar/13.11.3953] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
70S ribosomes from E. coli were chemically cross-linked under conditions of in vitro protein biosynthesis. The ribosomal RNAs were extracted from reacted ribosomes and separated on sucrose gradients. The 5S RNA was shown to contain the ribosomal protein L25 covalently bound. After total RNase T1 hydrolysis of the covalent RNA-protein complex several high molecular weight RNA fragments were obtained and identified by sequencing. One fragment, sequence region U103 to U120, was shown to be directly linked to the protein first by protein specific staining of the particular fragment and second by phosphor cellulose chromatography of the covalent RNA-protein complex. The other two fragments, U89 to G106 and A34 to G51, could not be shown to be directly linked to L25 but were only formed under cross-linking conditions. While the fragment U89 to G106 may be protected from RNase T1 digestion because of a strong interaction with the covalent RNA-protein complex, the formation of the fragment A34 to G51 is very likely the result of a double monovalent modification of two neighbouring guanosines in the 5S RNA. The RNA sequences U103 to U120 established to be in direct contact to the protein L25 within the ribosome falls into the sequence region previously proposed as L25 binding site from studies with isolated 5S RNA-protein complexes.
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