Interbase
Mostrando 13-21 de 21 artigos, teses e dissertações.
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13. Sensitivity of NMR internucleotide distances to B-DNA conformation: underlying mechanics.
Nuclear magnetic resonance (NMR) spectroscopy, combining correlated spectroscopy (COSY) coupling constant measurements with nuclear Overhauser effect spectroscopy (NOESY) interatomic distances, should make it possible to determine an averaged solution structure for DNA oligomers. However, even if such data could be obtained with high accuracy, it is not clea
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14. Variation of Type-B DNA X-Ray Fiber Diagrams with Base Composition
Eight natural DNAs of widely differing base composition have been studied by x-ray diffraction in fibers at high relative humidity. The resulting type B diffraction diagrams showed that all of the DNAs had a 34-Å pitch and 3.4-Å interbase pair separation. However, the intensity distribution on the inner three layer lines was a strong function of the base c
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15. Nuclear Overhauser effect study and assignment of D stem and reverse-Hoogsteen base pair proton resonances in yeast tRNAAsp.
Nuclear Overhauser effects (NOEs) in yeast tRNAAsp were found for all four GU and G psi base pairs. NOEs of both reverse-Hoogsteen pairs were identified by comparison with a purine C8 deuterated sample. Several NOEs involving these resonances were also found which are clearly between single protons on adjacent base pairs. These interbase NOEs, combined with
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16. Length changes in solution accompanying the B-Z transition of poly (dG-m5dC) induced by Co(NH3)63+.
Transient electric dichroism measurements have been used to observe the rotational relaxation times of 145 base pair fragments of poly (dGm5dC) and random sequence DNA to solution. From these the lengths of the fragments are calculated and the interbase pair separation or rise per base pair (RPB) calculated. The observations show that even in low salt, the a
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17. Conformation of Charged and Uncharged tRNAPhe
The effect of aminoacylation on the conformation of yeast tRNAPhe was investigated by high-resolution (300 MHz) proton nuclear magnetic resonance (NMR) spectroscopy. Resonances in the low-field (-11 to -15 ppm) region of the spectra are due to ring NH protons of Watson-Crick base pairs, and to a very high degree of approximation (within 0.05 ppm) the low-fie
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18. Secondary structure and stability of the selenocysteine insertion sequences (SECIS) for human thioredoxin reductase and glutathione peroxidase
We have used high resolution NMR and thermodynamics to characterize the secondary structure and stability of the selenocysteine insertion sequences (SECIS) of human glutathione peroxidase (58 nt) and thioredoxin reductase (51 nt). These sequences are members of the two classes of SECIS recently identified with two distinct structures capable of directing sel
Oxford University Press.
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19. A Non-canonical DNA Structure Enables Homologous Recombination in Various Genetic Systems*
Homologous recombination, which is critical to genetic diversity, depends on homologous pairing (HP). HP is the switch from parental to recombinant base pairs, which requires expansion of inter-base pair spaces. This expansion unavoidably causes untwisting of the parental double-stranded DNA. RecA/Rad51-catalyzed ATP-dependent HP is extensively stimulated in
American Society for Biochemistry and Molecular Biology.
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20. A UV resonance Raman study of hairpin dimer helices of d(A-G)10 at neutral pH containing intercalated dA residues and alternating dG tetrads.
The structure of the oligonucleotide d(A-G)10 in 0.6 M Na+, pH 7.0 has been investigated with UV resonance Raman (UVRR) spectroscopy. Variable wavelength excitation was used to distinguish the spectral contributions of dG and dA residues. Both classes of residues show UVRR hyperchromism with increasing temperature, reflecting unstacking of the bases. The dG
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21. Determination of base and backbone contributions to the thermodynamics of premelting and melting transitions in B DNA
In previous papers of this series the temperature-dependent Raman spectra of poly(dA)·poly(dT) and poly(dA–dT)·poly(dA–dT) were used to characterize structurally the melting and premelting transitions in DNAs containing consecutive A·T and alternating A·T/T·A base pairs. Here, we describe procedures for obtaining thermodynamic parameters from the Ra
Oxford University Press.