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Critical Reviews™ in Eukaryotic Gene Expression
Impact-faktor: 1.841 5-jähriger Impact-Faktor: 1.927 SJR: 0.649 SNIP: 0.516 CiteScore™: 1.96

ISSN Druckformat: 1045-4403
ISSN Online: 2162-6502

Critical Reviews™ in Eukaryotic Gene Expression

DOI: 10.1615/CritRevEukarGeneExpr.v9.i3-4.90
pages 245-255

Chromatin Structure Revisited

Jordanka Zlatanova
Biochip Technology Center, Argonne National Laboratory, Argonne, IL 60439-4833
Sanford H. Leuba
Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD, 20896-5055
Kensal van Holde
Department of Biochemistry and Biophysics, Oregon State University, Corvallis, OR 97331-7305

ABSTRAKT

Independently of the enormous progress in our understanding of the structure of the core particle, there remain a multitude of structural questions still to be answered. The main points discussed here can be summarized as follows: (1) The meaning of the term 'core particle' should be widened to reflect the fact that the actual length of DNA wrapped around the histone octamer in the context of the chromatin fiber may vary between ≈100 and ≈170 bp. (2) In the chromatosome, the linker histone forms a bridge between one terminus of the chromatosomal DNA and a point close to the dyad axis. (3) The particle that contains one molecule of HMG1 may be classified as a bona fide chromatosome. (4) In the extended fiber, the partition of the nucleosomal DNA into core and linker is a dynamic feature, responding to environmental influences; fiber structure-related constraints demand that linker length be beyond a certain minimal value. (5) The compact fiber structure seems to be rather irregular; the precise nature of this structure is still to be determined. Finally, the term 30-nm fiber should be dropped as a designator of the compact or condensed chromatin fiber structure.