Electron microscopy of nucleic acids and protein-nucleic acid complexes

The success of the protein monolayer technique for electron microscopy of individual DNA molecules is based on the prevention of aggregation and orientation of the molecules during drying on specimen grids. DNA adsorbs first to a surface-denatured, insoluble cytochrome c monolayer which is then transferred to grids, without major distortion, by touching. Fig. 1 shows three basic procedures which, modified or not, permit the study of various important properties of nucleic acids, either in concert with other methods or exclusively:1) Molecular weights relative to DNA standards as well as number distributions of molecular weights can be obtained from contour length measurements with a sample standard deviation between 1 and 4%.

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Snapshot blotting: The transfer of nucleic acids and nucleoprotein complexes from electrophoresis gels to EM grids

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100124215 ◽

1992 ◽

Vol 50 (1) ◽

pp. 762-763

Author(s):

Stephen D. Jett

Keyword(s):

Nucleic Acid ◽

Nucleic Acids ◽

Nucleic Acid Binding ◽

Mobility Shift ◽

Carbon Coated ◽

Nucleoprotein Complexes ◽

Mobility Shift Assay ◽

Protein Nucleic Acid ◽

Gel Mobility Shift ◽

Nucleic Acid Interactions

The electrophoresis gel mobility shift assay is a popular method for the study of protein-nucleic acid interactions. The binding of proteins to DNA is characterized by a reduction in the electrophoretic mobility of the nucleic acid. Binding affinity, stoichiometry, and kinetics can be obtained from such assays; however, it is often desirable to image the various species in the gel bands using TEM. Present methods for isolation of nucleoproteins from gel bands are inefficient and often destroy the native structure of the complexes. We have developed a technique, called “snapshot blotting,” by which nucleic acids and nucleoprotein complexes in electrophoresis gels can be electrophoretically transferred directly onto carbon-coated grids for TEM imaging.

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Electron Microscopy of Protein-Nucleic Acid Complexes: Uniform Spreading of Flexible Complexes, Staining with a Uniform Thin Layer of Uranyl Acetate, and Determining Helix Handedness

DNA-Protein Interactions ◽

10.1385/1-59259-208-2:579 ◽

2003 ◽

pp. 579-587

Author(s):

Carla W. Gray

Keyword(s):

Electron Microscopy ◽

Nucleic Acid ◽

Thin Layer ◽

Uranyl Acetate ◽

Protein Nucleic Acid

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Schematic diagrams of nucleic acids and protein–nucleic acid complexes

Journal of Applied Crystallography ◽

10.1107/s0021889889008265 ◽

1989 ◽

Vol 22 (6) ◽

pp. 569-571 ◽

Cited By ~ 2

Author(s):

V. I. Lesk ◽

A. M. Lesk

Keyword(s):

Nucleic Acid ◽

Nucleic Acids ◽

Complex Structures ◽

Acid Complex ◽

Protein Nucleic Acid ◽

Schematic Diagrams

Simplified representations of components of nucleic acids have been designed and implemented as programs integrated with other software that draws schematic diagrams of proteins. Examples illustrating the structures of oligonucleotides, tRNA and a protein–nucleic acid complex indicate the utility of these representations for making intelligible illustrations of complex structures containing nucleic acids.

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