Properties of two discrete classes of chromatin fiber structure

Range [1] diameter 33nm: ≈11 nucleosomes per 11 nm [2] diameter ≈44nm: ≈15 nucleosomes per 11 nm
Organism Eukaryotes
Reference Robinson PJ, Fairall L, Huynh VA, Rhodes D. EM measurements define the dimensions of the "30-nm" chromatin fiber: evidence for a compact, interdigitated structure. Proc Natl Acad Sci U S A. 2006 Apr 25 103(17):6506-11. p.6508 right column 2nd paragraphPubMed ID16617109
Comments "The production of very homogeneous and tightly folded 30-nm chromatin fibers from long nucleosome arrays with different nucleosome repeat lengths has permitted [researchers] to obtain accurate measurements of fiber dimensions and hence nucleosome packing ratios. Importantly, unlike previous chromatin reconstitution experiments (35, 38, 44), [their] nucleosome arrays contain a native-like complement of linker histone (11), which is critical for obtaining correct folding and maximal compaction (15, 32, 45). [Researchers] find that over the range of nucleosome repeat lengths analyzed, there are two discrete classes of fiber structure, one 33 nm in diameter and with ˜11 nucleosomes per 11 nm, and the other ˜44 nm in diameter and with ˜15 nucleosomes per 11 nm. This finding resolves the controversy in the literature, showing that the fiber diameter does not increase linearly with linker length."
Entered by Uri M
ID 111136