Related Experiment Videos
Dinucleosomes show compaction by ionic strength, consistent with bending of linker DNA
1MRC Laboratory of Molecular Biology, Hills Road, Cambridge, CB2 2QH, UK.
Journal of Molecular Biology
|August 12, 1998
Summary
Nucleosome dimers and trimers from chicken erythrocytes exhibit compaction at low ionic strengths. This suggests linker DNA may bend or kink, rather than remain straight.
Area of Science:
- Biochemistry
- Molecular Biology
- Genetics
Background:
- Nucleosomes are the basic units of DNA packaging in eukaryotes.
- The structure of chromatin, including linker DNA, influences gene regulation.
- Understanding nucleosome interactions is crucial for comprehending DNA organization.
Purpose of the Study:
- To investigate the structural behavior of nucleosome dimers and trimers from chicken erythrocytes.
- To determine the role of linker DNA in nucleosome compaction under varying ionic strengths.
Main Methods:
- Sedimentation coefficient analysis of nucleosome dimers and trimers.
- Ionic strength manipulation to observe structural changes.
Main Results:
- Nucleosome dimers showed ionic strength-dependent sedimentation coefficients similar to trimers.
- Evidence of compaction was observed within a specific range of low ionic strengths.
- The observed compaction is inconsistent with a straight linker DNA model.
Conclusions:
- The linker DNA between nucleosomes likely bends or kinks.
- This bending or kinking contributes to nucleosome compaction at low ionic strengths.
- Findings provide insights into the dynamic nature of DNA packaging in chromatin.