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Updated: May 24, 2026
10:40
Assembly of Nucleosomal Arrays from Recombinant Core Histones and Nucleosome Positioning DNA
Published on: September 10, 2013
Chromatin organization - the 30 nm fiber
Sergei A Grigoryev1, Christopher L Woodcock
1Department of Biochemistry and Molecular Biology, Penn State University College of Medicine, Hershey, PA 17033, USA.
Experimental Cell Research
|March 8, 2012
Summary
Eukaryotic chromatin structure is complex, but recent advances reveal unifying principles. The
Area of Science:
- Molecular Biology
- Genetics
- Biophysics
Background:
- The fundamental structure of eukaryotic chromatin has been debated for over 30 years.
- Discrepancies arise from studies using different chromatin preparations (in nuclei, isolated, or reconstituted).
Purpose of the Study:
- To review the historical controversy surrounding chromatin structure.
- To identify unifying principles in chromatin fiber architecture based on recent advances.
Main Methods:
- Review of existing literature.
- Analysis of data from imaging and modeling studies.
- Comparison of results from various chromatin study approaches.
Main Results:
- Recent advances clarify the structure of the '30 nm' chromatin fiber.
- Fiber architecture involves both zigzag and bent linker motifs, explaining high packing ratios.
- Interactions between fibers in compact chromatin lead to nucleosome interdigitation and loss of individual fiber resolution in situ.
Conclusions:
- Unifying principles are emerging for chromatin fiber architecture.
- Heteromorphic fiber structures are key to achieving high DNA packaging.
- Further research is needed to fully understand in vivo chromatin organization.
Related Concept Videos
02:21Chromatin Packaging
Each human somatic cell contains 6 billion base-pairs of DNA. Each base-pair is 0.34 nm long, which means that each diploid cell contains a staggering 2 meters of DNA. How is such a long DNA strand packed inside a nucleus measuring only 10 - 20 microns in diameter?
The chromatin
In combination with specialized DNA binding protein called Histones, the DNA double helix forms a compact DNA: protein complex called chromatin. The chromatin itself is further compacted into higher-order structures.
The chromatin
In combination with specialized DNA binding protein called Histones, the DNA double helix forms a compact DNA: protein complex called chromatin. The chromatin itself is further compacted into higher-order structures.
01:32Chromatin Packaging
Each human somatic cell contains 6 billion base pairs of DNA. Each base pair is 0.34 nm long, meaning each diploid cell contains a staggering 2 meters of DNA. This long DNA strand is packed inside a nucleus measuring only 10-20 microns in diameter with the help of specialized DNA-binding proteins called histones. Together they form a compact DNA-protein complex called chromatin. The chromatin is further compacted into higher-order structures. The highest level of compaction is achieved during...
02:21Chromatin Packaging
Each human somatic cell contains 6 billion base-pairs of DNA. Each base-pair is 0.34 nm long, which means that each diploid cell contains a staggering 2 meters of DNA. How is such a long DNA strand packed inside a nucleus measuring only 10 - 20 microns in diameter?
The chromatin
In combination with specialized DNA binding protein called Histones, the DNA double helix forms a compact DNA: protein complex called chromatin. The chromatin itself is further compacted into higher-order structures.
The chromatin
In combination with specialized DNA binding protein called Histones, the DNA double helix forms a compact DNA: protein complex called chromatin. The chromatin itself is further compacted into higher-order structures.
01:19The Nucleosome
Human DNA is almost two meters long. However, it is compressed inside a tiny nucleus measuring only a few microns in diameter. To make this degree of compaction possible, DNA is organized into several sequential levels so that it can fit into such a tiny space. The most compact form of DNA is a chromosome that can be seen under a microscope in a dividing cell.
In a chromosome, DNA is wound twice around a protein complex called a histone octamer core, which consists of 8 histone proteins. This...
In a chromosome, DNA is wound twice around a protein complex called a histone octamer core, which consists of 8 histone proteins. This...
02:33The Nucleosome
DNA in a human cell is almost 2m long and it is packed inside a tiny nucleus that is only a few microns in diameter. The level of compaction of DNA inside the nucleus is astonishing. It is organized into several sequentially higher levels of compaction to fit into such a tiny space. The most compact form of DNA is a chromosome that can be seen under a microscope in a dividing cell.
DNA is wound twice around a protein complex called histone core, that consist of 8 histone proteins. This complex...
DNA is wound twice around a protein complex called histone core, that consist of 8 histone proteins. This complex...
02:33The Nucleosome
DNA in a human cell is almost 2m long and it is packed inside a tiny nucleus that is only a few microns in diameter. The level of compaction of DNA inside the nucleus is astonishing. It is organized into several sequentially higher levels of compaction to fit into such a tiny space. The most compact form of DNA is a chromosome that can be seen under a microscope in a dividing cell.
DNA is wound twice around a protein complex called histone core, that consist of 8 histone proteins. This complex...
DNA is wound twice around a protein complex called histone core, that consist of 8 histone proteins. This complex...