A model for the tertiary structure of transfer ribonucleic acids

1969 ◽  
Vol 31 (2) ◽  
pp. 395-402 ◽  
Author(s):  
Tai Te Wu
Keyword(s):  
Tertiary Structure ◽  
Ribonucleic Acids

scholarly journals Tertiary structure of tRNAPhe. A possible correlation between the structural functional unit of this tRNA and its exonic sequence

1984 ◽  
Vol 219 (1) ◽  
pp. 341-344
Author(s):  
R Malathi ◽  
N Yathindra
Keyword(s):  
Tertiary Structure ◽  
Functional Unit ◽  
Classical Domain ◽  
Structural Units ◽  
Close Inspection ◽  
Ribonucleic Acids ◽  
Domain Structures ◽  
Shape Structure ◽  
Trna Species ◽  
Exonic Sequence

It has been shown recently [Go (1981) Nature (London) 291, 90-92; Blake (1983) Trends Biochem Sci. 8, 11-13] that the exonic regions of the genes of proteins haemoglobin, lysozyme and immunoglobin correspond closely to the compactly folded structural units. Despite the absence of classical domain structures in tRNA compared with those found in several proteins, close inspection of certain features in the distance maps obtained for yeast tRNAPhe using the conformationally equivalent heminucleotide scheme reveals that a similar situation might also be present in ribonucleic acids such as tRNA species and the exonic sequences of their genes. Also it seems possible that certain segments of yeast tRNAPhe may be characterized as possessing a domain-like character, and this seems to provide stereochemical support for possible conservation of L-shape structure for tRNA species lacking the entire dihydrouridine arm such as those found in mitochondria.

Novel Chemoenzymatic Synthesis of Azobenzene Functionalized Ribonucleic Acid

2000 ◽  
Vol 660 ◽  
Author(s):  
Sucharita Roy ◽  
Ramaswamy Nagarajan ◽  
Peichuan Wu ◽  
Sukant K. Tripathy ◽  
Jayant Kumar ◽  
...  
Keyword(s):  
Tertiary Structure ◽  
Covalent Attachment ◽  
Hydroxyl Group ◽  
Synthetic Approach ◽  
Buffer Solution ◽  
Ribonucleic Acids ◽  
Hydrocarbon Solvents ◽  
Rna Backbone ◽  
Device Applications

ABSTRACTRibonucleic acids, often called a biological jack of all trades, contribute intimately to every aspect of gene expression, including the synthesis of other polypeptide biocatalysts. The fundamental importance of recurring structural motifs and the kinetics and energetics of the complex secondary and tertiary structure of RNA have been shown to be intimately linked with its functions in vivo. We have developed a novel enzymatic synthetic approach for covalent attachment of photoresponsive units into the RNA backbone. The synthetic conditions of this approach are extremely mild, involving the reverse micellar solubilization of nucleic acid along with lipase in apolar hydrocarbon solvents. Lipase catalyzed acylation of the 2' hydroxyl group in the ribose sugars of the RNA molecule has been used to incorporate photo-isomerizable azobenzene groups into the RNA strands. This micellar approach was envisaged for RNA functionalization while maintaining the conformational integrity of the macromolecular backbone in neutral buffer solution. The modification of RNA using covalently attached chromophores or fluorophores can be extended to other biomacromolecular matrices leading to the development of more versatile photoactive biopolymers. The photo-isomerizable groups incorporated in the RNA molecule can serve as optical ‘handles’ for the manipulation of the conformation of RNA and open new opportunities for biophotonic device applications.

Tertiary Structure in Transfer Ribonucleic Acids

1966 ◽  
Vol 31 (0) ◽  
pp. 527-537 ◽  
Author(s):  
J. R. Fresco ◽  
A. Adams ◽  
R. Ascione ◽  
D. Henley ◽  
T. Lindahl
Keyword(s):  
Tertiary Structure ◽  
Ribonucleic Acids

Torus Circumference and Thickness Parameters From a Linear DNA Size Series Suggest How Toruses Self-Assemble

1985 ◽  
Vol 43 ◽  
pp. 522-523
Author(s):  
George C. Ruben ◽  
Kenneth A. Marx
Keyword(s):  
Tertiary Structure ◽  
Dna Complexes ◽  
Tertiary Structures ◽  
Self Assembling ◽  
Double Stranded Dna ◽  
Calf Thymus ◽  
Dna Organization ◽  
Condensed Dna ◽  
Dna Size

Certain double stranded DNA bacteriophage and viruses are thought to have their DNA organized into large torus shaped structures. Morphologically, these poorly understood biological DNA tertiary structures resemble spermidine-condensed DNA complexes formed in vitro in the total absence of other macromolecules normally synthesized by the pathogens for the purpose of their own DNA packaging. Therefore, we have studied the tertiary structure of these self-assembling torus shaped spermidine- DNA complexes in a series of reports. Using freeze-etch, low Pt-C metal (10-15Å) replicas, we have visualized the microscopic DNA organization of both calf Thymus( CT) and linear 0X-174 RFII DNA toruses. In these structures DNA is circumferentially wound, continuously, around the torus into a semi-crystalline, hexagonal packed array of parallel DNA helix sections.

Microscopic investigations of novel intracellular bodies of a Nocardia SP

1994 ◽  
Vol 52 ◽  
pp. 356-357
Author(s):  
J. L. Stites
Keyword(s):  
Uranyl Acetate ◽  
Electron Microscopic ◽  
En Bloc ◽  
Ribonucleic Acids ◽  
Transmission Electron ◽  
Nocardia Sp ◽  
Internal Constitution ◽  
Membrane Bound ◽  
Molecular Components ◽  
Protein Rich

A Nocardia sp.was found during an initial transmission electron microscopic (TEM) examination to have unusual intracellular bodies (ICB's) which do not appear to have been described previously in the literature. Most intracellular structures within bacteria have been classified as storage granules, a product of membrane invagination (i.e. mesosomes), or vacuoles. In bacteria there are no known intracellular membrane-bound organelles, and all internal membranes are invaginations of the unit membrane. Several microscopic-level examinations of the Nocardia sp. ICB's were initiated in order to determine their overall structure, classification, and internal constitution.Different TEM staining procedures were performed to determine possible molecular components of the ICB. In all of the staining protocols the ICB's showed a lack of electron density similar to the cell wall. Because the ICB's showed no affinity to any stain, it appeared they do not have strong positive charge (phosphotungstic acid), are not protein rich (en bloc uranyl acetate), lack glycogen and are not phosphate or sulphur rich (lead citrate), nor do they contain lipids or ribonucleic acids (osmium tetroxide).

Electronmicroscopic localization of ribonucleic acids in ciliate Bursaria truncatella during cell division

1990 ◽  
Vol 48 (3) ◽  
pp. 132-133
Author(s):  
Vladimir Popenko ◽  
Natalya Cherny ◽  
Maria Yakovleva
Keyword(s):  
Cell Division ◽  
High Specificity ◽  
Longitudinal Axis ◽  
Gold Complexes ◽  
Somatic Nucleus ◽  
Ribonucleic Acids ◽  
Biological Meaning ◽  
Bivalent Cations ◽  
Lowicryl K4m ◽  
Short Time

Highly polyploid somatic nucleus (macronucleus) of ciliate Bursaria truncatella under goes severe changes in morphology during cell division. At first, macronucleus (Ma) condences, diminishes in size and turns perpendicular to longitudinal axis of the cell. After short time, Ma turns again, elongates and only afterwards the process of division itself occurs. The biological meaning of these phenomena is not clear.Localization of RNA in the cells was performed on sections of ciliates B. truncatella, embedded in “Lowicryl K4M” at various stages: (1) before cell division (Figs. 2,3); (11) at the stage of macronucleus condensation; (111) during elongation of Ma (Fig.4); (1111) in young cells (0-5min. after division). For cytochemical labelling we used RNaseAcolloidal gold complexes (RNase-Au), which are known to bind to RNA containing cell ularstructures with high specificity. The influence of different parameters on the reliability and reproducibility of labelling was studied. In addition to the factors, discussed elsewhere, we found that the balance of mono- and bivalent cations is of great significance.

Droplet Factories: Synthesis and Assembly of Silver and Palladium Nanoparticles at the Liquid-Liquid Interface

2019 ◽  
Author(s):  
Suchanuch Sachdev ◽  
Rhushabh Maugi ◽  
Sam Davis ◽  
Scott Doak ◽  
Zhaoxia Zhou ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Reaction Rate ◽  
Tertiary Structure ◽  
Flow Reactor ◽  
Pd Nanoparticles ◽  
Subsequent Removal ◽  
Immiscible Liquids ◽  
Flow Reactors ◽  
Droplet Flow ◽  
One Step

<div>The interface between two immiscible liquids represent an ideal substrate for the assembly of nanomaterials. The defect free surface provides a reproducible support for creating densely packed ordered materials. Here a droplet flow reactor is presented for the synthesis and/ or assembly of nanomaterials at the interface of the emulsion. Each droplet acts as microreactor for a reaction between decamethylferrocene (DmFc) within the hexane and metal salts (Ag+/ Pd2+) in the aqueous phase. The hypothesis was that a spontaneous, interfacial reaction would lead to the assembly of nanomaterials creating a Pickering emulsion. The subsequent removal of the solvents showed how the Ag nanoparticles were trapped at the interface and retain the shape of the droplet, however the Pd nanoparticles were dispersed with no tertiary structure. To further exploit this, a one-step process where the particles are synthesised and then assembled into core-shell materials was proposed. The same reactions were performed in the presence of oleic acid stabilise Iron oxide nanoparticles dispersed within the hexane. It was shown that by changing the reaction rate and ratio between palladium and iron oxide a continuous coating of palladium onto iron oxide microspheres can be created. The same reaction with silver, was unsuccessful and resulted in the silver particles being shed into solution, or incorporated within the iron oxide micro particle. These insights offer a new method and chemistry within flow reactors for the creation of palladium and silver nanoparticles. We use the technique to create metal coated iron oxide nanomaterials but the methodology could be easily transferred to the assembly of other materials.</div><div><br></div>

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