Topology of zigzag chromatin.
An enormous length of DNA is packaged in the nuclei of eukaryotic cells. This is achieved through several intermediate levels of compaction, ranging from the double helix to the chromosome. The nucleosome is now firmly established as the first level of chromatin structure. Next it appears that the nucleosomes are themselves stacked in a two-track array, with a dinucleosome repeat. Several winding patterns of DNA are compatible with such a structure. It is shown here that, compared to other feasible DNA paths, the observed winding pattern has remarkable topological properties. The possible biological significance of this peculiarity is discussed.
D002843:Chromatin / Q000648:ultrastructure*; D004247:DNA; D008961:Models, Structural; D009690:Nucleic Acid Conformation; D009707:Nucleosomes / Q000648:ultrastructure
D002843:Chromatin; D009707:Nucleosomes; D004247:DNA