Abstract
In concentrated solution and in the presence of high concentrations of monovalent cations, nucleosome core particles order into a discotic columnar mesophase. This phase is limited to finite-sized hexagonal germs that further divide into six coiled branches, following an iterative process. We show how the structure of the germs comes from the competition between hexagonal packing and chirality with a combination of dendritic facetting and double-twist configurations. Geometrical considerations lead us to suspect that the chirality of the eukaryotic chromosomes may originate from the same competition.
Full Text
The Full Text of this article is available as a PDF (738.0 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Bohrmann B., Haider M., Kellenberger E. Concentration evaluation of chromatin in unstained resin-embedded sections by means of low-dose ratio-contrast imaging in STEM. Ultramicroscopy. 1993 Feb;49(1-4):235–251. doi: 10.1016/0304-3991(93)90230-u. [DOI] [PubMed] [Google Scholar]
- Boy de la Tour E., Laemmli U. K. The metaphase scaffold is helically folded: sister chromatids have predominantly opposite helical handedness. Cell. 1988 Dec 23;55(6):937–944. doi: 10.1016/0092-8674(88)90239-5. [DOI] [PubMed] [Google Scholar]
- Houchmandzadeh B., Marko J. F., Chatenay D., Libchaber A. Elasticity and structure of eukaryote chromosomes studied by micromanipulation and micropipette aspiration. J Cell Biol. 1997 Oct 6;139(1):1–12. doi: 10.1083/jcb.139.1.1. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kamien RD, Nelson DR. Defects in chiral columnar phases: Tilt-grain boundaries and iterated moiré maps. Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics. 1996 Jan;53(1):650–666. doi: 10.1103/physreve.53.650. [DOI] [PubMed] [Google Scholar]
- Kamien RD, Nelson DR. Iterated Moiré maps and braiding of chiral polymer crystals. Phys Rev Lett. 1995 Mar 27;74(13):2499–2502. doi: 10.1103/PhysRevLett.74.2499. [DOI] [PubMed] [Google Scholar]
- Leforestier A., Livolant F. Liquid crystalline ordering of nucleosome core particles under macromolecular crowding conditions: evidence for a discotic columnar hexagonal phase. Biophys J. 1997 Oct;73(4):1771–1776. doi: 10.1016/S0006-3495(97)78207-9. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Livolant F. Supramolecular organization of double-stranded DNA molecules in the columnar hexagonal liquid crystalline phase. An electron microscopic analysis using freeze-fracture methods. J Mol Biol. 1991 Mar 5;218(1):165–181. doi: 10.1016/0022-2836(91)90882-7. [DOI] [PubMed] [Google Scholar]
- Luger K., Mäder A. W., Richmond R. K., Sargent D. F., Richmond T. J. Crystal structure of the nucleosome core particle at 2.8 A resolution. Nature. 1997 Sep 18;389(6648):251–260. doi: 10.1038/38444. [DOI] [PubMed] [Google Scholar]
- Ohnuki Y. Structure of chromosomes. I. Morphological studies of the spiral structure of human somatic chromosomes. Chromosoma. 1968;25(4):402–428. doi: 10.1007/BF02327721. [DOI] [PubMed] [Google Scholar]