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Wang ZY, Qu WT, Mei T, Zhang N, Yang NY, Xu XF, Xiong HB, Yang ZN, Yu QB. AtRsmD Is Required for Chloroplast Development and Chloroplast Function in Arabidopsis thaliana. FRONTIERS IN PLANT SCIENCE 2022; 13:860945. [PMID: 35548310 PMCID: PMC9083416 DOI: 10.3389/fpls.2022.860945] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 03/16/2022] [Indexed: 05/25/2023]
Abstract
AtRsmD was recently demonstrated to be a chloroplast 16S rRNA methyltransferase (MTase) for the m2G915 modification in Arabidopsis. Here, its function of AtRsmD for chloroplast development and photosynthesis was further analyzed. The AtRsmD gene is highly expressed in green photosynthetic tissues. AtRsmD is associated with the thylakoid in chloroplasts. The atrsmd-2 mutant exhibited impaired photosynthetic efficiency in emerging leaves under normal growth conditions. A few thylakoid lamellas could be observed in the chloroplast from the atrsmd-2 mutant, and these thylakoids were loosely organized. Knockout of the AtRsmD gene had minor effects on chloroplast ribosome biogenesis and RNA loading on chloroplast ribosomes, but it reduced the amounts of chloroplast-encoded photosynthesis-related proteins in the emerging leaves, for example, D1, D2, CP43, and CP47, which reduced the accumulation of the photosynthetic complex. Nevertheless, knockout of the AtRsmD gene did not cause a general reduction in chloroplast-encoded proteins in Arabidopsis grown under normal growth conditions. Additionally, the atrsmd-2 mutant exhibited more sensitivity to lincomycin, which specifically inhibits the elongation of nascent polypeptide chains. Cold stress exacerbated the effect on chloroplast ribosome biogenesis in the atrsmd-2 mutant. All these data suggest that the AtRsmD protein plays distinct regulatory roles in chloroplast translation, which is required for chloroplast development and chloroplast function.
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2
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Ngoc LNT, Park SJ, Cai J, Huong TT, Lee K, Kang H. RsmD, a Chloroplast rRNA m2G Methyltransferase, Plays a Role in Cold Stress Tolerance by Possibly Affecting Chloroplast Translation in Arabidopsis. PLANT & CELL PHYSIOLOGY 2021; 62:948-958. [PMID: 34015128 DOI: 10.1093/pcp/pcab060] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 05/04/2021] [Accepted: 05/19/2021] [Indexed: 06/12/2023]
Abstract
Ribosomal RNA (rRNA) methylation is a pivotal process in the assembly and activity of ribosomes, which in turn play vital roles in the growth, development and stress responses of plants. Although few methyltransferases responsible for rRNA methylation have been identified in plant chloroplasts, the nature and function of these enzymes in chloroplasts remain largely unknown. In this study, we characterized ArabidopsisRsmD (At3g28460), an ortholog of the methyltransferase responsible for N2-methylguanosine (m2G) modification of 16S rRNA in Escherichia coli. Confocal microscopic analysis of an RsmD- green fluorescent protein fusion protein revealed that RsmD is localized to chloroplasts. Primer extension analysis indicated that RsmD is responsible for m2G methylation at position 915 in the 16S rRNA of Arabidopsis chloroplasts. Under cold stress, rsmd mutant plants exhibited retarded growth, i.e. had shorter roots, lower fresh weight and pale-green leaves, compared with wild-type (WT) plants. However, these phenotypes were not detected in response to drought or salt stress. Notably, the rsmd mutant was hypersensitive to erythromycin or lincomycin and accumulated fewer chloroplast proteins compared with the WT, suggesting that RsmD influences translation in chloroplasts. Complementation lines expressing RsmD in the rsmd mutant background recovered WT phenotypes. Importantly, RsmD harbored RNA methyltransferase activity. Collectively, the findings of this study indicate that RsmD is a chloroplast 16S rRNA methyltransferase responsible for m2G915 modification that plays a role in the adaptation of Arabidopsisto cold stress.
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Affiliation(s)
- Le Nguyen Tieu Ngoc
- Department of Applied Biology, College of Agriculture and Life Sciences, Chonnam National University, Gwangju 61186, South Korea
- Faculty of Forestry Agriculture, Tay Nguyen University, Buon Ma Thuot, Daklak 63000, Vietnam
| | - Su Jung Park
- Department of Applied Biology, College of Agriculture and Life Sciences, Chonnam National University, Gwangju 61186, South Korea
| | - Jing Cai
- Department of Applied Biology, College of Agriculture and Life Sciences, Chonnam National University, Gwangju 61186, South Korea
| | - Trinh Thi Huong
- Department of Applied Biology, College of Agriculture and Life Sciences, Chonnam National University, Gwangju 61186, South Korea
- The Western Highlands Agriculture and Forestry Science Institute, Buon Ma Thuot, Daklak 63000, Vietnam
| | - Kwanuk Lee
- Department of Applied Biology, College of Agriculture and Life Sciences, Chonnam National University, Gwangju 61186, South Korea
| | - Hunseung Kang
- Department of Applied Biology, College of Agriculture and Life Sciences, Chonnam National University, Gwangju 61186, South Korea
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3
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Golubev A, Fatkhullin B, Khusainov I, Jenner L, Gabdulkhakov A, Validov S, Yusupova G, Yusupov M, Usachev K. Cryo‐EM structure of the ribosome functional complex of the human pathogen
Staphylococcus aureus
at 3.2 Å resolution. FEBS Lett 2020; 594:3551-3567. [DOI: 10.1002/1873-3468.13915] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 08/11/2020] [Accepted: 08/17/2020] [Indexed: 12/14/2022]
Affiliation(s)
- Alexander Golubev
- Laboratory of Structural Biology Institute of Fundamental Medicine and Biology Kazan Federal University Russia
- Département de Biologie et de Génomique Structurales Institut de Génétique et de Biologie Moléculaire et Cellulaire CNRS UMR7104INSERM U964Université de Strasbourg Illkirch France
| | - Bulat Fatkhullin
- Laboratory of Structural Biology Institute of Fundamental Medicine and Biology Kazan Federal University Russia
- Institute of Protein Research Russian Academy of Sciences Puschino Russia
| | - Iskander Khusainov
- Laboratory of Structural Biology Institute of Fundamental Medicine and Biology Kazan Federal University Russia
- Department of Molecular Sociology Max Planck Institute of Biophysics Frankfurt am Main Germany
| | - Lasse Jenner
- Département de Biologie et de Génomique Structurales Institut de Génétique et de Biologie Moléculaire et Cellulaire CNRS UMR7104INSERM U964Université de Strasbourg Illkirch France
| | - Azat Gabdulkhakov
- Laboratory of Structural Biology Institute of Fundamental Medicine and Biology Kazan Federal University Russia
- Institute of Protein Research Russian Academy of Sciences Puschino Russia
| | - Shamil Validov
- Laboratory of Structural Biology Institute of Fundamental Medicine and Biology Kazan Federal University Russia
| | - Gulnara Yusupova
- Département de Biologie et de Génomique Structurales Institut de Génétique et de Biologie Moléculaire et Cellulaire CNRS UMR7104INSERM U964Université de Strasbourg Illkirch France
| | - Marat Yusupov
- Laboratory of Structural Biology Institute of Fundamental Medicine and Biology Kazan Federal University Russia
- Département de Biologie et de Génomique Structurales Institut de Génétique et de Biologie Moléculaire et Cellulaire CNRS UMR7104INSERM U964Université de Strasbourg Illkirch France
| | - Konstantin Usachev
- Laboratory of Structural Biology Institute of Fundamental Medicine and Biology Kazan Federal University Russia
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4
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Hammerling MJ, Fritz BR, Yoesep DJ, Kim DS, Carlson ED, Jewett MC. In vitro ribosome synthesis and evolution through ribosome display. Nat Commun 2020; 11:1108. [PMID: 32111839 PMCID: PMC7048773 DOI: 10.1038/s41467-020-14705-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Accepted: 01/28/2020] [Indexed: 02/04/2023] Open
Abstract
Directed evolution of the ribosome for expanded substrate incorporation and novel functions is challenging because the requirement of cell viability limits the mutations that can be made. Here we address this challenge by combining cell-free synthesis and assembly of translationally competent ribosomes with ribosome display to develop a fully in vitro methodology for ribosome synthesis and evolution (called RISE). We validate the RISE method by selecting active genotypes from a ~1.7 × 107 member library of ribosomal RNA (rRNA) variants, as well as identifying mutant ribosomes resistant to the antibiotic clindamycin from a library of ~4 × 103 rRNA variants. We further demonstrate the prevalence of positive epistasis in resistant genotypes, highlighting the importance of such interactions in selecting for new function. We anticipate that RISE will facilitate understanding of molecular translation and enable selection of ribosomes with altered properties. Directed evolution of the ribosome is challenging because the requirement of cell viability limits the mutations that can be made. Here the authors develop a platform for in vitro ribosome synthesis and evolution (RISE) to overcome these constraints.
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Affiliation(s)
- Michael J Hammerling
- Department of Chemical and Biological Engineering, Northwestern University, 2145 Sheridan Road, Evanston, Illinois, 60208, USA
| | - Brian R Fritz
- Department of Chemical and Biological Engineering, Northwestern University, 2145 Sheridan Road, Evanston, Illinois, 60208, USA
| | - Danielle J Yoesep
- Department of Chemical and Biological Engineering, Northwestern University, 2145 Sheridan Road, Evanston, Illinois, 60208, USA
| | - Do Soon Kim
- Department of Chemical and Biological Engineering, Northwestern University, 2145 Sheridan Road, Evanston, Illinois, 60208, USA
| | - Erik D Carlson
- Department of Chemical and Biological Engineering, Northwestern University, 2145 Sheridan Road, Evanston, Illinois, 60208, USA.,Department of Chemical Engineering, Stanford University, Stanford, California, 94305, USA
| | - Michael C Jewett
- Department of Chemical and Biological Engineering, Northwestern University, 2145 Sheridan Road, Evanston, Illinois, 60208, USA. .,Center for Synthetic Biology, Northwestern University, 2145 Sheridan Road, Evanston, Illinois, 60208, USA. .,Simpson Querrey Institute, Northwestern University, 2145 Sheridan Road, Evanston, Illinois, 60208, USA. .,Chemistry of Life Processes Institute, Northwestern University, 2145 Sheridan Road, Evanston, Illinois, 60208, USA. .,Robert H. Lurie Comprehensive Cancer Center, Northwestern University, 2145 Sheridan Road, Evanston, Illinois, 60208, USA.
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5
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Muley VY, Akhter Y, Galande S. PDZ Domains Across the Microbial World: Molecular Link to the Proteases, Stress Response, and Protein Synthesis. Genome Biol Evol 2019; 11:644-659. [PMID: 30698789 PMCID: PMC6411480 DOI: 10.1093/gbe/evz023] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/25/2019] [Indexed: 02/07/2023] Open
Abstract
The PSD-95/Dlg-A/ZO-1 (PDZ) domain is highly expanded, diversified, and well distributed across metazoa where it assembles diverse signaling components by virtue of interactions with other proteins in a sequence-specific manner. In contrast, in the microbial world they are reported to be involved in protein quality control during stress response. The distribution, functions, and origins of PDZ domain-containing proteins in the prokaryotic organisms remain largely unexplored. We analyzed 7,852 PDZ domain-containing proteins in 1,474 microbial genomes in this context. PDZ domain-containing proteins from planctomycetes, myxobacteria, and other eubacteria occupying terrestrial and aquatic niches are found to be in multiple copies within their genomes. Over 93% of the 7,852 PDZ domain-containing proteins were classified into 12 families including six novel families based on additional structural and functional domains present in these proteins. The higher PDZ domain encoding capacity of the investigated organisms was observed to be associated with adaptation to the ecological niche where multicellular life might have originated and flourished. Predicted subcellular localization of PDZ domain-containing proteins and their genomic context argue in favor of crucial roles in translation and membrane remodeling during stress response. Based on rigorous sequence, structure, and phylogenetic analyses, we propose that the highly diverse PDZ domain of the uncharacterized Fe-S oxidoreductase superfamily, exclusively found in gladobacteria and several anaerobes and acetogens, might represent the most ancient form among all the existing PDZ domains.
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Affiliation(s)
- Vijaykumar Yogesh Muley
- Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, México
- Department of Biology, Indian Institute of Science Education and Research, Pune, India
| | - Yusuf Akhter
- Department of Biotechnology, Babasaheb Bhimrao Ambedkar University, Lucknow, India
| | - Sanjeev Galande
- Department of Biology, Indian Institute of Science Education and Research, Pune, India
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6
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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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7
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Polikanov YS, Melnikov SV, Söll D, Steitz TA. Structural insights into the role of rRNA modifications in protein synthesis and ribosome assembly. Nat Struct Mol Biol 2015; 22:342-344. [PMID: 25775268 PMCID: PMC4401423 DOI: 10.1038/nsmb.2992] [Citation(s) in RCA: 188] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Accepted: 02/17/2015] [Indexed: 11/23/2022]
Abstract
We report crystal structures of the Thermus thermophilus ribosome at 2.3- to 2.5-Å resolution, which have enabled modeling of rRNA modifications. The structures reveal contacts of modified nucleotides with mRNA and tRNAs or protein pY, and contacts within the ribosome interior stabilizing the functional fold of rRNA. Our work provides a resource to explore the roles of rRNA modifications and yields a more comprehensive atomic model of a bacterial ribosome.
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Affiliation(s)
- Yury S Polikanov
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
- Howard Hughes Medical Institute at Yale University, New Haven, CT, USA
| | - Sergey V Melnikov
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
| | - Dieter Söll
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
- Department of Chemistry, Yale University, New Haven, CT, USA
| | - Thomas A Steitz
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
- Howard Hughes Medical Institute at Yale University, New Haven, CT, USA
- Department of Chemistry, Yale University, New Haven, CT, USA
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8
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Sergeeva OV, Bogdanov AA, Sergiev PV. What do we know about ribosomal RNA methylation in Escherichia coli? Biochimie 2014; 117:110-8. [PMID: 25511423 DOI: 10.1016/j.biochi.2014.11.019] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2014] [Accepted: 11/20/2014] [Indexed: 11/18/2022]
Abstract
A ribosome is a ribonucleoprotein that performs the synthesis of proteins. Ribosomal RNA of all organisms includes a number of modified nucleotides, such as base or ribose methylated and pseudouridines. Methylated nucleotides are highly conserved in bacteria and some even universally. In this review we discuss available data on a set of modification sites in the most studied bacteria, Escherichia coli. While most rRNA modification enzymes are known for this organism, the function of the modified nucleotides is rarely identified.
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MESH Headings
- Escherichia coli/genetics
- Escherichia coli/metabolism
- Escherichia coli Proteins/chemistry
- Escherichia coli Proteins/metabolism
- Methylation
- Methyltransferases/chemistry
- Methyltransferases/metabolism
- Models, Molecular
- Nucleic Acid Conformation
- Protein Binding
- RNA, Bacterial/chemistry
- RNA, Bacterial/genetics
- RNA, Bacterial/metabolism
- RNA, Messenger/chemistry
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- RNA, Ribosomal/chemistry
- RNA, Ribosomal/genetics
- RNA, Ribosomal/metabolism
- Ribosomes/genetics
- Ribosomes/metabolism
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Affiliation(s)
- O V Sergeeva
- Chemistry Department, Lomonosov Moscow State University, Moscow 119991, Russia; Skolkovo Institute of Science and Technology, Skolkovo, Moscow 143025, Russia.
| | - A A Bogdanov
- Chemistry Department, Lomonosov Moscow State University, Moscow 119991, Russia; Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119991, Russia
| | - P V Sergiev
- Chemistry Department, Lomonosov Moscow State University, Moscow 119991, Russia; Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119991, Russia
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9
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Gill JJ, Berry JD, Russell WK, Lessor L, Escobar-Garcia DA, Hernandez D, Kane A, Keene J, Maddox M, Martin R, Mohan S, Thorn AM, Russell DH, Young R. The Caulobacter crescentus phage phiCbK: genomics of a canonical phage. BMC Genomics 2012; 13:542. [PMID: 23050599 PMCID: PMC3556154 DOI: 10.1186/1471-2164-13-542] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2012] [Accepted: 10/01/2012] [Indexed: 11/30/2022] Open
Abstract
Background The bacterium Caulobacter crescentus is a popular model for the study of cell cycle regulation and senescence. The large prolate siphophage phiCbK has been an important tool in C. crescentus biology, and has been studied in its own right as a model for viral morphogenesis. Although a system of some interest, to date little genomic information is available on phiCbK or its relatives. Results Five novel phiCbK-like C. crescentus bacteriophages, CcrMagneto, CcrSwift, CcrKarma, CcrRogue and CcrColossus, were isolated from the environment. The genomes of phage phiCbK and these five environmental phage isolates were obtained by 454 pyrosequencing. The phiCbK-like phage genomes range in size from 205 kb encoding 318 proteins (phiCbK) to 280 kb encoding 448 proteins (CcrColossus), and were found to contain nonpermuted terminal redundancies of 10 to 17 kb. A novel method of terminal ligation was developed to map genomic termini, which confirmed termini predicted by coverage analysis. This suggests that sequence coverage discontinuities may be useable as predictors of genomic termini in phage genomes. Genomic modules encoding virion morphogenesis, lysis and DNA replication proteins were identified. The phiCbK-like phages were also found to encode a number of intriguing proteins; all contain a clearly T7-like DNA polymerase, and five of the six encode a possible homolog of the C. crescentus cell cycle regulator GcrA, which may allow the phage to alter the host cell’s replicative state. The structural proteome of phage phiCbK was determined, identifying the portal, major and minor capsid proteins, the tail tape measure and possible tail fiber proteins. All six phage genomes are clearly related; phiCbK, CcrMagneto, CcrSwift, CcrKarma and CcrRogue form a group related at the DNA level, while CcrColossus is more diverged but retains significant similarity at the protein level. Conclusions Due to their lack of any apparent relationship to other described phages, this group is proposed as the founding cohort of a new phage type, the phiCbK-like phages. This work will serve as a foundation for future studies on morphogenesis, infection and phage-host interactions in C. crescentus.
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Affiliation(s)
- Jason J Gill
- Center for Phage Technology, 2128 TAMU, Texas A&M University, College Station, Texas, TX 77843, USA
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10
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Burakovsky DE, Prokhorova IV, Sergiev PV, Milón P, Sergeeva OV, Bogdanov AA, Rodnina MV, Dontsova OA. Impact of methylations of m2G966/m5C967 in 16S rRNA on bacterial fitness and translation initiation. Nucleic Acids Res 2012; 40:7885-95. [PMID: 22649054 PMCID: PMC3439901 DOI: 10.1093/nar/gks508] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The functional centers of the ribosome in all organisms contain ribosomal RNA (rRNA) modifications, which are introduced by specialized enzymes and come at an energy cost for the cell. Surprisingly, none of the modifications tested so far was essential for growth and hence the functional role of modifications is largely unknown. Here, we show that the methyl groups of nucleosides m2G966 and m5C967 of 16S rRNA in Escherichia coli are important for bacterial fitness. In vitro analysis of all phases of translation suggests that the m2G966/m5C967 modifications are dispensable for elongation, termination and ribosome recycling. Rather, the modifications modulate the early stages of initiation by stabilizing the binding of fMet-tRNAfMet to the 30S pre-initiation complex prior to start-codon recognition. We propose that the m2G966 and m5C967 modifications help shaping the bacterial proteome, most likely by fine-tuning the rates that determine the fate of a given messenger RNA (mRNA) at early checkpoints of mRNA selection.
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11
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Abeydeera ND, Chow CS. Synthesis and characterization of modified nucleotides in the 970 hairpin loop of Escherichia coli 16S ribosomal RNA. Bioorg Med Chem 2009; 17:5887-93. [PMID: 19628400 PMCID: PMC2725200 DOI: 10.1016/j.bmc.2009.07.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2009] [Revised: 06/29/2009] [Accepted: 07/03/2009] [Indexed: 12/23/2022]
Abstract
The synthesis of the 6-O-DPC-2-N-methylguanosine (m(2)G) nucleoside and the corresponding 5'-O-DMT-2'-O-TOM-protected 6-O-DPC-2-N-methylguanosine phosphoramidite is reported [DPC, diphenyl carbamoyl; DMT, 4,4'-dimethoxytrityl; TOM, [(triisopropylsilyl)oxy]methyl]. The availability of the phosphoramidite allows for syntheses of hairpin RNAs with site-selective incorporation of 2-N-methylguanosine modification. Four 18-nt hairpin RNA analogues representing the 970-loop region (helix 31 or h31; U960-A975) of Escherichia coli 16S rRNA were synthesized with and without modifications in the loop region. Subsequently, stabilities and conformations of the singly and doubly modified RNAs were examined and compared with the corresponding unmodified RNA. Thermodynamic parameters and circular dichroism spectra are presented for the four helix 31 RNA analogues. Surprisingly, methylations in the loop region of helix 31 slightly destabilize the hairpin, which may have subtle effects on ribosome function. The hairpin construct is suitable for future ligand-binding experiments.
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12
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Demirci H, Gregory ST, Dahlberg AE, Jogl G. Crystal structure of the Thermus thermophilus 16 S rRNA methyltransferase RsmC in complex with cofactor and substrate guanosine. J Biol Chem 2008; 283:26548-56. [PMID: 18667428 PMCID: PMC2546533 DOI: 10.1074/jbc.m804005200] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2008] [Revised: 07/22/2008] [Indexed: 01/16/2023] Open
Abstract
Post-transcriptional modification is a ubiquitous feature of ribosomal RNA in all kingdoms of life. Modified nucleotides are generally clustered in functionally important regions of the ribosome, but the functional contribution to protein synthesis is not well understood. Here we describe high resolution crystal structures for the N(2)-guanine methyltransferase RsmC that modifies residue G1207 in 16 S rRNA near the decoding site of the 30 S ribosomal subunit. RsmC is a class I S-adenosyl-L-methionine-dependent methyltransferase composed of two methyltransferase domains. However, only one S-adenosyl-L-methionine molecule and one substrate molecule, guanosine, bind in the ternary complex. The N-terminal domain does not bind any cofactor. Two structures with bound S-adenosyl-L-methionine and S-adenosyl-L-homocysteine confirm that the cofactor binding mode is highly similar to other class I methyltransferases. Secondary structure elements of the N-terminal domain contribute to cofactor-binding interactions and restrict access to the cofactor-binding site. The orientation of guanosine in the active site reveals that G1207 has to disengage from its Watson-Crick base pairing interaction with C1051 in the 16 S rRNA and flip out into the active site prior to its modification. Inspection of the 30 S crystal structure indicates that access to G1207 by RsmC is incompatible with the native subunit structure, consistent with previous suggestions that this enzyme recognizes a subunit assembly intermediate.
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Affiliation(s)
| | | | | | - Gerwald Jogl
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown
University, Providence, Rhode Island 02912
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13
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Saraiya AA, Lamichhane TN, Chow CS, SantaLucia J, Cunningham PR. Identification and role of functionally important motifs in the 970 loop of Escherichia coli 16S ribosomal RNA. J Mol Biol 2007; 376:645-57. [PMID: 18177894 DOI: 10.1016/j.jmb.2007.11.102] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2007] [Revised: 11/26/2007] [Accepted: 11/30/2007] [Indexed: 10/22/2022]
Abstract
The 970 loop (helix 31) of Escherichia coli 16S ribosomal RNA contains two modified nucleotides, m(2)G966 and m(5)C967. Positions A964, A969, and C970 are conserved among the Bacteria, Archaea, and Eukarya. The nucleotides present at positions 965, 966, 967, 968, and 971, however, are only conserved and unique within each domain. All organisms contain a modified nucleoside at position 966, but the type of the modification is domain specific. Biochemical and structure studies have placed this loop near the P site and have shown it to be involved in the decoding process and in binding the antibiotic tetracycline. To identify the functional components of this ribosomal RNA hairpin, the eight nucleotides of the 970 loop of helix 31 were subjected to saturation mutagenesis and 107 unique functional mutants were isolated and analyzed. Nonrandom nucleotide distributions were observed at each mutated position among the functional isolates. Nucleotide identity at positions 966 and 969 significantly affects ribosome function. Ribosomes with single mutations of m(2)G966 or m(5)C967 produce more protein in vivo than do wild-type ribosomes. Overexpression of initiation factor 3 specifically restored wild-type levels of protein synthesis to the 966 and 967 mutants, suggesting that modification of these residues is important for initiation factor 3 binding and for the proper initiation of protein synthesis.
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Affiliation(s)
- Ashesh A Saraiya
- Department of Biological Sciences, Wayne State University, Detroit, MI 48202, USA
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14
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Sunita S, Purta E, Durawa M, Tkaczuk KL, Swaathi J, Bujnicki JM, Sivaraman J. Functional specialization of domains tandemly duplicated within 16S rRNA methyltransferase RsmC. Nucleic Acids Res 2007; 35:4264-74. [PMID: 17576679 PMCID: PMC1934991 DOI: 10.1093/nar/gkm411] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
RNA methyltransferases (MTases) are important players in the biogenesis and regulation of the ribosome, the cellular machine for protein synthesis. RsmC is a MTase that catalyzes the transfer of a methyl group from S-adenosyl-l-methionine (SAM) to G1207 of 16S rRNA. Mutations of G1207 have dominant lethal phenotypes in Escherichia coli, underscoring the significance of this modified nucleotide for ribosome function. Here we report the crystal structure of E. coli RsmC refined to 2.1 A resolution, which reveals two homologous domains tandemly duplicated within a single polypeptide. We characterized the function of the individual domains and identified key residues involved in binding of rRNA and SAM, and in catalysis. We also discovered that one of the domains is important for the folding of the other. Domain duplication and subfunctionalization by complementary degeneration of redundant functions (in particular substrate binding versus catalysis) has been reported for many enzymes, including those involved in RNA metabolism. Thus, RsmC can be regarded as a model system for functional streamlining of domains accompanied by the development of dependencies concerning folding and stability.
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Affiliation(s)
- S. Sunita
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543, Laboratory of Bioinformatics and Protein Engineering, International Institute of Molecular and Cell Biology, Trojdena 4, 02-109 Warsaw, Institute of Biochemistry and Biophysics PAS, Pawinskiego 5a, 02-106 Warsaw and Institute of Technical Biochemistry, Technical University of Lodz, B. Stefanowskiego 4/10, 90-924 Lodz, Poland
| | - Elzbieta Purta
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543, Laboratory of Bioinformatics and Protein Engineering, International Institute of Molecular and Cell Biology, Trojdena 4, 02-109 Warsaw, Institute of Biochemistry and Biophysics PAS, Pawinskiego 5a, 02-106 Warsaw and Institute of Technical Biochemistry, Technical University of Lodz, B. Stefanowskiego 4/10, 90-924 Lodz, Poland
| | - Malgorzata Durawa
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543, Laboratory of Bioinformatics and Protein Engineering, International Institute of Molecular and Cell Biology, Trojdena 4, 02-109 Warsaw, Institute of Biochemistry and Biophysics PAS, Pawinskiego 5a, 02-106 Warsaw and Institute of Technical Biochemistry, Technical University of Lodz, B. Stefanowskiego 4/10, 90-924 Lodz, Poland
| | - Karolina L. Tkaczuk
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543, Laboratory of Bioinformatics and Protein Engineering, International Institute of Molecular and Cell Biology, Trojdena 4, 02-109 Warsaw, Institute of Biochemistry and Biophysics PAS, Pawinskiego 5a, 02-106 Warsaw and Institute of Technical Biochemistry, Technical University of Lodz, B. Stefanowskiego 4/10, 90-924 Lodz, Poland
| | - J. Swaathi
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543, Laboratory of Bioinformatics and Protein Engineering, International Institute of Molecular and Cell Biology, Trojdena 4, 02-109 Warsaw, Institute of Biochemistry and Biophysics PAS, Pawinskiego 5a, 02-106 Warsaw and Institute of Technical Biochemistry, Technical University of Lodz, B. Stefanowskiego 4/10, 90-924 Lodz, Poland
| | - Janusz M. Bujnicki
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543, Laboratory of Bioinformatics and Protein Engineering, International Institute of Molecular and Cell Biology, Trojdena 4, 02-109 Warsaw, Institute of Biochemistry and Biophysics PAS, Pawinskiego 5a, 02-106 Warsaw and Institute of Technical Biochemistry, Technical University of Lodz, B. Stefanowskiego 4/10, 90-924 Lodz, Poland
| | - J. Sivaraman
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543, Laboratory of Bioinformatics and Protein Engineering, International Institute of Molecular and Cell Biology, Trojdena 4, 02-109 Warsaw, Institute of Biochemistry and Biophysics PAS, Pawinskiego 5a, 02-106 Warsaw and Institute of Technical Biochemistry, Technical University of Lodz, B. Stefanowskiego 4/10, 90-924 Lodz, Poland
- *To whom correspondence should be addressed. +65 65161163+65 67792486
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15
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Sergiev PV, Bogdanov AA, Dontsova OA. Ribosomal RNA guanine-(N2)-methyltransferases and their targets. Nucleic Acids Res 2007; 35:2295-301. [PMID: 17389639 PMCID: PMC1874633 DOI: 10.1093/nar/gkm104] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Five nearly universal methylated guanine-(N2) residues are present in bacterial rRNA in the ribosome. To date four out of five ribosomal RNA guanine-(N2)-methyltransferases are described. RsmC(YjjT) methylates G1207 of the 16S rRNA. RlmG(YgjO) and RlmL(YcbY) are responsible for the 23S rRNA m2G1835 and m2G2445 formation, correspondingly. RsmD(YhhF) is necessary for methylation of G966 residue of 16S rRNA. Structure of Escherichia coli RsmD(YhhF) methyltransferase and the structure of the Methanococcus jannaschii RsmC ortholog were determined. All ribosomal guanine-(N2)-methyltransferases have similar AdoMet-binding sites. In relation to the ribosomal substrate recognition, two enzymes that recognize assembled subunits are relatively small single domain proteins and two enzymes that recognize naked rRNA are larger proteins containing separate methyltransferase- and RNA-binding domains. The model for recognition of specific target nucleotide is proposed. The hypothetical role of the m2G residues in rRNA is discussed.
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Affiliation(s)
| | | | - Olga A. Dontsova
- *To whom correspondence should be addressed. +7-495-9395418+7-495-9393181
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16
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Lesnyak DV, Osipiuk J, Skarina T, Sergiev PV, Bogdanov AA, Edwards A, Savchenko A, Joachimiak A, Dontsova OA. Methyltransferase that modifies guanine 966 of the 16 S rRNA: functional identification and tertiary structure. J Biol Chem 2007; 282:5880-7. [PMID: 17189261 PMCID: PMC2885967 DOI: 10.1074/jbc.m608214200] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
N(2)-Methylguanine 966 is located in the loop of Escherichia coli 16 S rRNA helix 31, forming a part of the P-site tRNA-binding pocket. We found yhhF to be a gene encoding for m(2)G966 specific 16 S rRNA methyltransferase. Disruption of the yhhF gene by kanamycin resistance marker leads to a loss of modification at G966. The modification could be rescued by expression of recombinant protein from the plasmid carrying the yhhF gene. Moreover, purified m(2)G966 methyltransferase, in the presence of S-adenosylomethionine (AdoMet), is able to methylate 30 S ribosomal subunits that were purified from yhhF knock-out strain in vitro. The methylation is specific for G966 base of the 16 S rRNA. The m(2)G966 methyltransferase was crystallized, and its structure has been determined and refined to 2.05A(.) The structure closely resembles RsmC rRNA methyltransferase, specific for m(2)G1207 of the 16 S rRNA. Structural comparisons and analysis of the enzyme active site suggest modes for binding AdoMet and rRNA to m(2)G966 methyltransferase. Based on the experimental data and current nomenclature the protein expressed from the yhhF gene was renamed to RsmD. A model for interaction of RsmD with ribosome has been proposed.
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Affiliation(s)
- Dmitry V. Lesnyak
- Department of Bioinformatics and Bioengineering, Moscow State University, Moscow 119992, Russia
| | - Jerzy Osipiuk
- Midwest Center for Structural Genomics and Structural Biology Center, Biosciences Division, Argonne National Laboratory, Argonne, Illinois 60439
| | - Tatiana Skarina
- Banting and Best Department of Medical Research, University of Toronto, Toronto, Ontario M5G IL6, Canada
| | - Petr V. Sergiev
- Department of Chemistry and A.N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow 119992, Russia
| | - Alexey A. Bogdanov
- Department of Chemistry and A.N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow 119992, Russia
| | - Aled Edwards
- Banting and Best Department of Medical Research, University of Toronto, Toronto, Ontario M5G IL6, Canada
| | - Alexei Savchenko
- Banting and Best Department of Medical Research, University of Toronto, Toronto, Ontario M5G IL6, Canada
| | - Andrzej Joachimiak
- Midwest Center for Structural Genomics and Structural Biology Center, Biosciences Division, Argonne National Laboratory, Argonne, Illinois 60439
| | - Olga A. Dontsova
- Department of Chemistry and A.N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow 119992, Russia
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17
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Gerrits MM, de Zoete MR, Arents NLA, Kuipers EJ, Kusters JG. 16S rRNA mutation-mediated tetracycline resistance in Helicobacter pylori. Antimicrob Agents Chemother 2002; 46:2996-3000. [PMID: 12183259 PMCID: PMC127406 DOI: 10.1128/aac.46.9.2996-3000.2002] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Most Helicobacter pylori strains are susceptible to tetracycline, an antibiotic commonly used for the eradication of H. pylori. However, an increase in incidence of tetracycline resistance in H. pylori has recently been reported. Here the mechanism of tetracycline resistance of the first Dutch tetracycline-resistant (Tet(r)) H. pylori isolate (strain 181) is investigated. Twelve genes were selected from the genome sequences of H. pylori strains 26695 and J99 as potential candidate genes, based on their homology with tetracycline resistance genes in other bacteria. With the exception of the two 16S rRNA genes, none of the other putative tetracycline resistance genes was able to transfer tetracycline resistance. Genetic transformation of the Tet(s) strain 26695 with smaller overlapping PCR fragments of the 16S rRNA genes of strain 181, revealed that a 361-bp fragment that spanned nucleotides 711 to 1071 was sufficient to transfer resistance. Sequence analysis of the 16S rRNA genes of the Tet(r) strain 181, the Tet(s) strain 26695, and four Tet(r) 26695 transformants showed that a single triple-base-pair substitution, AGA(926-928)-->TTC, was present within this 361-bp fragment. This triple-base-pair substitution, present in both copies of the 16S rRNA gene of all our Tet(r) H. pylori transformants, resulted in an increased MIC of tetracycline that was identical to that for the Tet(r) strain 181.
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Affiliation(s)
- Monique M Gerrits
- Department of Gastroenterology and Hepatology, Erasmus MC-University Medical Center Rotterdam, The Netherlands
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18
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O'Connor M, Thomas CL, Zimmermann RA, Dahlberg AE. Decoding fidelity at the ribosomal A and P sites: influence of mutations in three different regions of the decoding domain in 16S rRNA. Nucleic Acids Res 1997; 25:1185-93. [PMID: 9092628 PMCID: PMC146559 DOI: 10.1093/nar/25.6.1185] [Citation(s) in RCA: 101] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The involvement of defined regions of Escherichia coli 16S rRNA in the fidelity of decoding has been examined by analyzing the effects of rRNA mutations on misreading errors at the ribosomal A and P sites. Mutations in the 1400-1500 region, the 530 loop and in the 1050/1200 region (helix 34) all caused readthrough of stop codons and frameshifting during elongation and stimulated initiation from non-AUG codons at the initiation of protein synthesis. These results indicate the involvement of all three regions of 16S rRNA in decoding functions at both the A and P sites. The functional similarity of all three mutant classes are consistent with close physical proximity of the 1400- 1500 region, the 530 loop and helix 34 and suggest that all three regions of rRNA comprise a decoding domain in the ribosome.
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Affiliation(s)
- M O'Connor
- Department of Molecular and Cell Biology and Biochemistry, Box G, J. W.Wilson Laboratory, Brown University, Providence, RI 02912, USA. Michael_O'
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19
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Jemiolo DK, Pagel FT, Murgola EJ. UGA suppression by a mutant RNA of the large ribosomal subunit. Proc Natl Acad Sci U S A 1995; 92:12309-13. [PMID: 8618891 PMCID: PMC40346 DOI: 10.1073/pnas.92.26.12309] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
A role for rRNA in peptide chain termination was indicated several years ago by isolation of a 168 rRNA (small subunit) mutant of Escherichia coli that suppressed UGA mutations. In this paper, we describe another interesting rRNA mutant, selected as a translational suppressor of the chain-terminating mutant trpA (UGA211) of E. coli. The finding that it suppresses UGA at two positions in trpA and does not suppress the other two termination codons, UAA and UAG, at the same codon positions (or several missense mutations, including UGG, available at one of the two positions) suggests a defect in UGA-specific termination. The suppressor mutation was mapped by plasmid fragment exchanges and in vivo suppression to domain II of the 23S rRNA gene of the rrnB operon. Sequence analysis revealed a single base change of G to A at residue 1093, an almost universally conserved base in a highly conserved region known to have specific interactions with ribosomal proteins, elongation factor G, tRNA in the A-site, and the peptidyltransferase region of 23S rRNA. Several avenues of action of the suppressor mutation are suggested, including altered interactions with release factors, ribosomal protein L11, or 16S rRNA. Regardless of the mechanism, the results indicate that a particular residue in 23S rRNA affects peptide chain termination, specifically in decoding of the UGA termination codon.
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MESH Headings
- Base Sequence
- Codon
- Escherichia coli/genetics
- Escherichia coli/metabolism
- Genes, Bacterial
- Models, Structural
- Molecular Sequence Data
- Mutagenesis
- Nucleic Acid Conformation
- Operon
- Peptide Chain Termination, Translational
- Plasmids
- RNA, Ribosomal, 16S/genetics
- RNA, Ribosomal, 16S/metabolism
- RNA, Ribosomal, 23S/genetics
- RNA, Ribosomal, 23S/metabolism
- Restriction Mapping
- Ribosomal Proteins/metabolism
- Suppression, Genetic
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Affiliation(s)
- D K Jemiolo
- Department of Molecular Genetics, University of Texas M.D. Anderson Cancer Center, Houston 77030, USA
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20
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Triman KL. Growth properties associated with A-U replacement of specific G-C base pairs in 16S rRNA from Escherichia coli. J Bacteriol 1995; 177:4514-6. [PMID: 7543481 PMCID: PMC177204 DOI: 10.1128/jb.177.15.4514-4516.1995] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Mutations that disrupt each of seven specific G-C base pairs in 16S rRNA from Escherichia coli confer loss of expression of a plasmid-encoded 16S rRNA selectable marker (spectinomycin resistance). However, A-U replacement of G-C base pairs at nucleotides 359/52 or 1292/1245 in 16S rRNA permits normal expression of the marker. By contrast, A-U replacements at 146/176, 153/168, 350/339, or 1293/1244 are associated with loss of expression of the marker. These genetic studies are designed to determine the importance of specific base pairs by assessment of the structural and functional impairments of 16S rRNA molecules resulting from expression of base pair substitutions at these positions.
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Affiliation(s)
- K L Triman
- Department of Biology, Franklin and Marshall College, Lancaster, Pennsylvania 17604, USA
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21
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Triman KL. Mutational analysis of 16S ribosomal RNA structure and function in Escherichia coli. ADVANCES IN GENETICS 1995; 33:1-39. [PMID: 7484450 DOI: 10.1016/s0065-2660(08)60329-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- K L Triman
- Department of Biology, Franklin and Marshall College, Lancaster, Pennsylvania 17604, USA
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22
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Pinard R, Côté M, Payant C, Brakier-Gingras L. Positions 13 and 914 in Escherichia coli 16S ribosomal RNA are involved in the control of translational accuracy. Nucleic Acids Res 1994; 22:619-24. [PMID: 7510397 PMCID: PMC307852 DOI: 10.1093/nar/22.4.619] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Using a conditional expression system with the temperature-inducible lambda PL promoter, we previously showed that the single mutations 13U-->A and 914A-->U, and the double mutation 13U-->A and 914A-->U in Escherichia coli 16S ribosomal RNA impair the binding of streptomycin (Pinard et al., The FASEB Journal, 1993, 7, 173-176). In this study, we found that the two single mutations and the double mutation increase translational fidelity, reducing in vivo readthrough of nonsense codons and frameshifting, and decreasing in vitro misincorporation in a poly(U)-directed system. Using oligodeoxyribonucleotide probes which hybridize to the 530 loop and to the 1400 region of 16S rRNA, two regions involved in the control of tRNA binding to the A site, we observed that the mutations in rRNA increase the binding of the probe to the 530 loop but not to the 1400 region. We suggest that the mutations at positions 13 and 914 of 16S rRNA induce a conformational rearrangement in the 530 loop, which contributes to the increased accuracy of the ribosome.
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Affiliation(s)
- R Pinard
- Département de Biochimie, Université de Montréal, Québec, Canada
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23
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Rydén-Aulin M, Shaoping Z, Kylsten P, Isaksson LA. Ribosome activity and modification of 16S RNA are influenced by deletion of ribosomal protein S20. Mol Microbiol 1993; 7:983-92. [PMID: 7683367 DOI: 10.1111/j.1365-2958.1993.tb01190.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
A spontaneous mutant of Escherichia coli K-12 was isolated that shows an increased misreading ability of all three nonsense codons together with an inability to grow at 42 degrees C. It is demonstrated that the mutation is a deletion of the gene rpsT, coding for ribosomal protein S20. The loss of this protein not only influences the decoding properties of the ribosome; the modification pattern of 16S ribosomal RNA is also changed. This leads to a deficiency in the ability of the mutant to associate its 30S subunits with 50S subunits to form 70S ribosomes. It is suggested that two modified bases, m5C and m6(2)A, are directly or indirectly essential for association of subunits to functional ribosomes in the rpsT mutant strain. Two other modifications were also studied; m2G which is not affected at all and m3U which is undermodified in both active and inactive subunits and, therefore, not involved in subunit association.
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Affiliation(s)
- M Rydén-Aulin
- Department of Microbiology, Stockholm University, Sweden
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