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Generation and Purification of Human INO80 Chromatin Remodeling Complexes and Subcomplexes
Published on: October 23, 2014
Structural studies of the human PBAF chromatin-remodeling complex
Andres E Leschziner1, Bryan Lemon, Robert Tjian
1Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
Structure (London, England : 1993)
|February 9, 2005
Summary
The human PBAF chromatin remodeling complex has a C-shaped structure that surrounds a central cavity. This cavity is where the nucleosome binds, according to electron microscopy and image analysis.
Area of Science:
- Molecular Biology
- Structural Biology
- Epigenetics
Background:
- ATP-dependent chromatin remodeling is crucial for regulating DNA transactions by altering chromatin structure.
- The precise mechanisms by which remodeling complexes modify nucleosome structure remain largely unknown.
- Structural insights are vital for interpreting biochemical and genetic data on chromatin remodelers.
Purpose of the Study:
- To determine the structure of the human PBAF ATP-dependent chromatin-remodeling complex.
- To map the nucleosome binding site of the PBAF complex.
- To elucidate the structural basis of PBAF-mediated chromatin remodeling.
Main Methods:
- Negative stain electron microscopy was used to determine the structure of the human PBAF complex.
- Two-dimensional (2D) image analysis was employed to map the nucleosome binding site.
- PBAF:nucleosome complexes were analyzed to understand their interaction.
Main Results:
- The human PBAF complex exhibits a C-shaped architecture with a central cavity.
- Two smaller knobs are attached to the larger density, with one knob showing flexibility.
- 2D image analysis revealed that the nucleosome binds within the central cavity of the PBAF complex.
Conclusions:
- The determined structure of the human PBAF complex provides a framework for understanding its function.
- The nucleosome binding site is located in the central cavity, suggesting a mechanism for DNA transaction regulation.
- Further structural and biochemical studies are warranted to fully elucidate PBAF's role in chromatin remodeling.
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