Mobility And Accessibility
Mostrando 25-36 de 44 artigos, teses e dissertações.
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25. Energy-dependent chromatin accessibility and nucleosome mobility in a cell-free system.
Chromatin structure must be flexible to allow the binding of regulatory proteins and to accommodate different levels of gene activity. Chromatin assembled in a cell-free system derived from Drosophila embryos contains an activity that hydrolyses ATP to render entire nucleosome arrays mobile. Nucleosome movements, most likely their sliding, occurred even in t
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26. Network of Dynamic Interactions between Histone H1 and High-Mobility-Group Proteins in Chromatin
Histone H1 and the high-mobility group (HMG) proteins are chromatin binding proteins that regulate gene expression by modulating the compactness of the chromatin fiber and affecting the ability of regulatory factors to access their nucleosomal targets. Histone H1 stabilizes the higher-order chromatin structure and decreases nucleosomal access, while the HMG
American Society for Microbiology.
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27. Two distinct conformations of rat liver ribosomal 5S RNA.
Three different conformers of rat liver 5S ribosomal RNA were investigated by partial nuclease cleavage technique using S1 nuclease and cobra venom endoribonuclease (CVE) as conformational probes. Urea-treated and renatured 5S RNA co-migrate on non-denaturing gels, but exhibit distinct differences in their nuclease cleavage patterns. The most prominent diffe
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28. The baculovirus transactivator IE1 binds to viral enhancer elements in the absence of insect cell factors.
The transregulatory IE1 protein of Autographa californica nuclear polyhedrosis virus binds to the viral enhancer element hr5. To test whether IE1 binds independently of host cell factors, IE1 was translated in rabbit reticulocyte extracts and tested for DNA binding activity by an electrophoretic mobility shift assay. Complexes with the hr5 probe were detecte
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29. Hydroxyl radical footprints reveal novel structural features around the NF I binding site in adenovirus DNA.
We have identified a number of as yet unknown structural abnormalities of the NF I-DNA binding site within the inverted terminal repetition of adenovirus DNA by probing it with a hydroxyl radical footprinting technique. NF I binding alters the accessibility of the deoxyribose moieties to hydroxyl radicals both at the 3' and at the 5' side of the recognition
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30. Cloning and expression of the ponB gene, encoding penicillin-binding protein 1B of Escherichia coli, in heterologous systems.
A fragment from the ponB region of the Escherichia coli chromosome comprising the promoterless sequence encoding penicillin-binding protein 1B (PBP 1B) has been cloned in a broad-host-range expression vector under the control of the kanamycin resistance gene promoter present in the vector. The hybrid plasmid (pJP3) was used to transform appropriate strains o
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31. Spontaneous Access of Proteins to Buried Nucleosomal DNA Target Sites Occurs via a Mechanism That Is Distinct from Nucleosome Translocation
Intrinsic nucleosome dynamics termed “site exposure” provides spontaneous and cooperative access to buried regions of nucleosomal DNA in vitro. Two different mechanisms for site exposure have been proposed, one based on nucleosome translocation, the other on dynamic nucleosome conformational changes in which a stretch of the nucleosomal DNA is transientl
American Society for Microbiology.
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32. Structure of the inhibitory region of troponin by site directed spin labeling electron paramagnetic resonance
Site-directed spin labeling EPR (SDSL-EPR) was used to determine the structure of the inhibitory region of TnI in the intact cardiac troponin ternary complex. Maeda and collaborators have modeled the inhibitory region of TnI (skeletal 96–112: the structural motif that communicates the Ca2+ signal to actin) as a kinked α-helix [Vassylyev, D., Takeda, S., W
The National Academy of Sciences.
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33. Semi-automated, single-band peak-fitting analysis of hydroxyl radical nucleic acid footprint autoradiograms for the quantitative analysis of transitions
Hydroxyl radical footprinting can probe the solvent accessibility of the ribose moiety of the individual nucleotides of DNA and RNA. Semi-automated analytical tools are presented for the quantitative analyses of nucleic acid footprint transitions in which processes such as folding or ligand binding are followed as a function of time or ligand concentration.
Oxford University Press.
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34. Effect of dilution rate on lipopolysaccharide and serum resistance of Neisseria gonorrhoeae grown in continuous culture.
Growth of Neisseria gonorrhoeae strain FA171 in continuous culture under glucose-limiting conditions resulted in a growth-rate-dependent change in the lipopolysaccharide (LPS). The evidence for this change is an alteration in the mobility of purified alkali-treated LPS on sodium dodecyl sulfate-polyacrylamide gels and a quantitative difference in the amount
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35. Antigenic determinants in proteins coincide with surface regions accessible to large probes (antibody domains).
We evaluated surface areas on proteins that would be accessible to contacts with large (1-nm radius) spherical probes. Such spheres are comparable in size to antibody domains that contain antigen-combining sites. We found that all the reported antigenic sites correspond to segments particularly accessible to a large sphere. The antigenic sites were also evid
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36. Heat-modifiable envelope proteins of Bordetella pertussis.
Several envelope proteins of Bordetella pertussis demonstrated differences in electrophoretic mobility, depending upon solubilization temperature before sodium dodecyl sulfate-polyacrylamide gel electrophoresis. These proteins were exposed on the cell surface as judged by their accessibility to radiolabeling with 125I. Monoclonal antibodies to two of the hea