Download or read book Escherichia Coli 3 terminal 16S RRNA Sequence Modulated Fidelity During Translation written by Fazilah Abdul Latif and published by . This book was released on 1993 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ribosome is a central component of the protein synthetic apparatus. Although progress has been made in characterizing the functional role of many of the ribosomal proteins, the properties of ribosomal RNA and its role in robosomal structure and function are not well understood. To investigate the working properties of the highly conserved 3'-end of 16S rRNA, a site-specific deletion was made directly within the 16S rRNA molecule. The terminal delection did not impair in vitro 30S subunit assembly, but the praticles produced lost translational fidelity in an vitro translation system primed with natural mRNA. [Authors' abstract].
Download or read book Modulation of Translational Fidelity by Small Subunit Ribosoma RNA from Escherichia Coli written by Fazilah Abdul-Latif and published by . This book was released on 1988 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ribosomes are ribonucleoprotein particles that are essential for the process of protein synthesis in all living systems. Escherichia coli, eubacterial organisms, have ribosomes which display a 70S sedimentation coefficient. They are formed by the association of two ribonucleoprotein subunits which sediment at 50S and 30S. The 30S subunit is a construct made of 21 different proteins and 16S ribosomal RNA. The 3'-terminus of this rRNA was the focus of the research recounted in this dissertation. This tract of 10 nucleotides in rRNA is absolutely conserved in eubacterial organisms and is asserted to be crucial for proper initiation of protein synthesis in eubacteria. Here I report the results of experiments done with 16S rRNA missing a part of the conserved 3'-terminus. These experiments were undertaken to provide a refinement of our understanding of the requirement for and function of this conserved segment of 16S rRNA. The deletions were made directly within mature 16S rRNA using RNase H and a 10 nucleotide synthetic DNA complementary to the 3'-terminus of 16S rRNA. The synthetic DNA was hybridized to 16S rRNA and then treated with RNase H. RNase H will only attack RNA when it is basepaired with DNA. This permits site-directed mutagenisis on the mature RNA. This deletion strategy efficiently yielded a 3'-terminal nucleotide deletion in E. coli 16S rRNA. This 3'-terminal deletion did not impair in vitro 30S subunit assembly. Therefore, the conservation of the sequence is not necessary for ribosome assembly. To investigate the functional properties of the modified particles an in vitro protein translation system primed with a natural mRNA was employed. The mRNA was viral MS2 messenger. Modified particles did translate the MS2 mRNA but the fidelity with which the translation occurred was diminished.
Download or read book Cumulated Index Medicus written by and published by . This book was released on 1988 with total page 1272 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Molecular Studies of the Fidelity of Translation Elongation written by Aishwarya Devaraj and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Protein synthesis occurs in ribosomes, megadalton RNA-protein machines that use aminoacyl-tRNA (aa-tRNA) molecules to translate messenger RNA (mRNA) with high fidelity. During translation elongation, the ribosome orchestrates 3 major events: decoding, peptidyl transfer and translocation. The process of proteins synthesis is also one of the major targets of antibiotics and hence understanding the basics of ribosome function should provide insight for the development of novel drugs. Genomes are maintained and expressed with remarkable fidelity and the accuracy of each process involved represents a compromise that optimizes the evolutionary fitness of the organism. The process of translation elongation is a complex one, and therefore there are potentially many ways the process can go awry. Chapter 1 introduces translation elongation errors and discusses the differences between missense, nonsense and frameshift errors. Mutations in the ribosome and other translation factors that affect the fidelity of translation elongation are also discussed. Chapter 2 is focused on the ribosomal exit (E) site and its role in maintaining the translational reading frame. It has been proposed that a critical role for the E site is in maintenance of translational reading frame, dependent on codon-anticodon pairing (191). Though several studies support the idea that codon-anticodon interaction in the E site contributes to frame maintenance (167), direct in vivo evidence for this hypothesis has been scant. In chapter 2, we investigated this fundamental question and found that the E site helps to maintain the reading frame, but does not contribute to the accuracy of decoding, as has been suggested (chapter 2, 204). We also showed that the mutation of the 30S E site does not inhibit EF-G-catalyzed translocation, in sharp contrast to the effects of mutations in 50S E site. These data provided evidence that the function of the E site in translocation is largely confined to the 50S subunit. One of the earliest identified examples of translational frameshifting occurs in the prfB gene of E. coli, encoding the peptide release factor 2 (RF2). While the genetic studies have identified the determinants of prfB programmed frameshifting and their relative importance, how these determinants act to promote frameshifting has remained unclear. In chapter 3, we compared ribosomal complexes with various spacer lengths between the SD sequence and P codon. We found that a close juxtaposition of the SD-ASD helix and P codon strongly destabilized P-site tRNA but had little or no effect on RF2-dependent termination or EF-Tu-dependent decoding. These data suggested that the intragenic SD of prfB destabilizes pairing of peptidyl-tRNALeu to the zero-frame CUU and promotes directional movement of the mRNA template with respect to the bound tRNA. In chapter 4, we have isolated 16S rRNA mutations that could suppress a +1 frameshift mutation in E. coli. In one of the screens (where the slippery sequence in the frameshift window had a stop codon), 31 independent mutations were identified and mapped to four different positions, of which C1054U was isolated 28 times. The C1054U mutation has also been isolated previously as a nonsense suppressor. Purine substitutions at this position also increased UGA readthrough and miscoding. While the C1054U mutation significantly increased nonsense readthrough and frameshift errors, the mutation had a hyperaccurate phenotype with respect to decoding (i.e., reduced misreading). Other substitutions at this position also had differential effects on the three reporters (missense, nonsense and frameshift). These interesting observations prompted us to characterize these A-site mutations as well as others in 16S rRNA (C1200U, G1491A and G299A) in vitro to get a better understanding of how the ribosome maintains its high fidelity (chapter 5). We investigated the effect of these mutations on RF2 function and found that all of the mutations tested had a defect in RF2-dependent termination. We directly tested the effect of these mutations on decoding by measuring the rate of GTP hydrolysis in both cognate and near-cognate mRNA. We found that all of the mutations tested (C1200U, G1491A, C1054U, C1054A, and G299A) had a substantial defect in initial selection, increasing the rate of GTP hydrolysis particularly on near-cognate mRNA. We also investigated the effect of these mutations on the stability of various tRNAs in the A site. Of the mutations analyzed, C1054U and G1491A seemed to differentially affect tRNA stability, suggesting that these mutations may stimulate GTP hydrolysis in a different way than the others.
Download or read book Dissertation Abstracts International written by and published by . This book was released on 1989 with total page 770 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Regulating with RNA in Bacteria and Archaea written by Gisela Storz and published by John Wiley & Sons. This book was released on 2020-07-10 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt: Revealing the many roles of RNA in regulating gene expression For decades after the discoveries of messenger RNA, transfer RNA, and ribosomal RNA, it was largely assumed that the role of RNA in the cell was limited to shuttling the genomic message, chaperoning amino acids, and toiling in the ribosomes. Eventually, hints that RNA molecules might have regulatory roles began to appear. With the advent of genomics and bioinformatics, it became evident that numerous other RNA forms exist and have specific functions, including small RNAs (sRNA), RNA thermometers, and riboswitches to regulate core metabolic pathways, bacterial pathogenesis, iron homeostasis, quorum sensing, and biofilm formation. All of these functions, and more, are presented in Regulating with RNA in Bacteria and Archaea, written by RNA biologists from around the globe. Divided into eight sections-RNases and Helicases, Cis-Acting RNAs, Cis Encoded Base Pairing RNAs, Trans-Encoded Base Pairing RNAs, Protein Titration and Scaffolding, General Considerations, Emerging Topics, and Resources-this book serves as an excellent resource for established RNA biologists and for the many scientists who are studying regulated cellular systems. It is no longer a fair assumption that gene expression regulation is the provenance of proteins only or that control is exerted primarily at the level of transcription. This book makes clear that regulatory RNAs are key partners along with proteins in controlling the complex interactions and pathways found within prokaryotes.
Download or read book Protein Synthesis and Ribosome Structure written by Knud H. Nierhaus and published by John Wiley & Sons. This book was released on 2004-10-15 with total page 608 pages. Available in PDF, EPUB and Kindle. Book excerpt: Knud Nierhaus, who has studied the ribosome for more than 30 years, has assembled here the combined efforts of several scientific disciplines into a uniform picture of the largest enzyme complex found in living cells, finally resolving many decades-old questions in molecular biology. In so doing he considers virtually all aspects of ribosome structure and function -- from the molecular mechanism of different ribosomal ribozyme activities to their selective inhibition by antibiotics, from assembly of the core particle to the regulation of ribosome component synthesis. The result is a premier resource for anyone with an interest in ribosomal protein synthesis, whether in the context of molecular biology, biotechnology, pharmacology or molecular medicine.
Download or read book Index Medicus written by and published by . This book was released on 2002 with total page 1656 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vols. for 1963- include as pt. 2 of the Jan. issue: Medical subject headings.
Download or read book Translation Mechanisms and Control written by Michael B. Mathews and published by . This book was released on 2018-09-30 with total page 499 pages. Available in PDF, EPUB and Kindle. Book excerpt: A subject collection from Cold Spring Harbor Perspectives in Biology.
Download or read book Proceedings of the National Academy of Sciences of the United States of America written by National Academy of Sciences (U.S.) and published by . This book was released on 1987 with total page 768 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Eukaryotic Ribosome written by Heinz Bielka and published by Walter de Gruyter GmbH & Co KG. This book was released on 1982-12-31 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt: No detailed description available for "The Eukaryotic Ribosome".
Download or read book Structural Aspects Of Protein Synthesis 2nd Edition written by Anders Liljas and published by World Scientific. This book was released on 2013-06-06 with total page 494 pages. Available in PDF, EPUB and Kindle. Book excerpt: This highly illustrated book provides an up-to-date description of the structure and function of the translation system including ribosomes, tRNAs, translation factors, antibiotics and aminoacyl-tRNA synthetases.Research on translation is undergoing rapid changes and is receiving significant attention as evidenced by the Nobel Prize in Chemistry 2009. The structural research by crystallography and cryo-EM forms part of an interactive framework that involves biochemistry and molecular computation. The book provides a comprehensive overview of translation in light of the structural results. It is a valuable resource for scientists in this and related fields, as well as for students taking courses with a focus on translation.There is no other book in this field currently except the previous edition of this book. The authors have for a long time worked in the field of structure and function of the translation system.
Download or read book Industrial Microorganisms written by Richard H. Baltz and published by ASM Press. This book was released on 1993 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is based on the proceedings of the 5th ASM Conference on the Genetics and Molecular Biology of Industrial Microorganisms held in Bloomington, Indiana in October 1992. The meeting focussed on prokaryotes and lower eukaryotes, with the programme balanced between streptomyces, fungi and yeasts, and other bacteria including Escherichia coli and emerging bacterial systems. The topics of the symposia reflect major trends in research that have immediate and future industrial applications
Download or read book Recoding Expansion of Decoding Rules Enriches Gene Expression written by John F. Atkins and published by Springer Science & Business Media. This book was released on 2010-03-10 with total page 473 pages. Available in PDF, EPUB and Kindle. Book excerpt: The literature on recoding is scattered, so this superb book ?lls a need by prov- ing up-to-date, comprehensive, authoritative reviews of the many kinds of recoding phenomena. Between 1961 and 1966 my colleagues and I deciphered the genetic code in Escherichia coli and showed that the genetic code is the same in E. coli, Xenopus laevis, and guinea pig tissues. These results showed that the code has been c- served during evolution and strongly suggested that the code appeared very early during biological evolution, that all forms of life on earth descended from a c- mon ancestor, and thus that all forms of life on this planet are related to one another. The problem of biological time was solved by encoding information in DNA and retrieving the information for each new generation, for it is easier to make a new organism than it is to repair an aging, malfunctioning one. Subsequently, small modi?cations of the standard genetic code were found in certain organisms and in mitochondria. Mitochondrial DNA only encodes about 10–13 proteins, so some modi?cations of the genetic code are tolerated that pr- ably would be lethal if applied to the thousands of kinds of proteins encoded by genomic DNA.
Download or read book Desk Encyclopedia of Microbiology written by Moselio Schaechter and published by Academic Press. This book was released on 2010-04-19 with total page 1277 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Desk Encyclopedia of Microbiology, Second Edition is a single-volume comprehensive guide to microbiology for the advanced reader. Derived from the six volume e-only Encyclopedia of Microbiology, Third Edition, it bridges the gap between introductory texts and specialized reviews. Covering topics ranging from the basic science of microbiology to the current "hot" topics in the field, it will be invaluable for obtaining background information on a broad range of microbiological topics, preparing lectures and preparing grant applications and reports. - The most comprehensive single-volume source providing an overview of microbiology to non-specialists - Bridges the gap between introductory texts and specialized reviews - Provides concise and general overviews of important topics within the field making it a helpful resource when preparing for lectures, writing reports, or drafting grant applications
Download or read book Nucleic Acids Abstracts written by and published by . This book was released on 1997 with total page 916 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Aminoacyl tRNA Synthetases written by Michael Ibba and published by CRC Press. This book was released on 2005-04-01 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: By virtue of their role as catalysts of the aminoacylation reaction, the aminoacyl-tRNA synthetases ensure that the first step of translation is performed quickly and accurately. In this volume of 36 separate chapters, the many facets of this ancient and ubiquitous family are reviewed, including their surprising structural diversity, enzymology, tRNA interaction properties, and curious alternative functions. These chapters illustrate the degree to which the aminoacyl-tRNA synthetases employ a variety of mechanisms to carry out both the standard functions related to the synthesis of aminoacylated tRNA for protein synthesis, as well as the surprising functions associated with amino acid biosynthesis, cytokine function, and even the processivity of DNA replication. Other chapters explore the regulation of their synthesis, their role in disease, and their prospects as targets for antibacterial therapeutics. This monograph will be a valuable resource for all scientists interested in the fundamentals of protein synthesis from both a basic research and clinical perspective, as well as the relation of translational components to the evolution of the genetic code.
