RT Journal Article ID 2eadd5ac74b4eb7b A1 Zlatanova, Jordanka A1 Leuba, Sanford H. A1 van Holde, Kensal T1 Chromatin Structure Revisited JF Critical Reviews™ in Eukaryotic Gene Expression JO CRE YR 1999 FD 1999-12-20 VO 9 IS 3-4 SP 245 OP 255 K1 core particle K1 chromatosome K1 linker histone K1 HMG1 K1 extended chromatin fiber K1 condensed chromatin fiber. AB 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. PB Begell House LK https://www.dl.begellhouse.com/journals/6dbf508d3b17c437,7831059776a36f5d,2eadd5ac74b4eb7b.html