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PMID: 6940168 Published · ppublish English Journal Article

Structure of chromatin and the linking number of DNA.

Proceedings of the National Academy of Sciences of the United States of America ·Vol. 78 ·No. 3 ·1981-03-00 ·Pages 1461-5

Worcel A, Strogatz S, Riley D

Abstract

Recent observations suggest that the basic supranucleosomal structure of chromatin is a zigzag helical ribbon with a repeat unit made of two nucleosomes connected by a relaxed spacer DNA. A remarkable feature of one particular ribbon is that it solves the apparent paradox between the number of DNA turns per nucleosome and the total linking number of a nucleosome-containing closed circular DNA molecule. We show here that the repeat unit of the proposed structure, which contains two nucleosomes with -1 3/4 DNA turns per nucleosome and one spacer crossover per repeat, contributes -2 to the linking number of closed circular DNA. Space-filling models show that the cylindrical 250-A chromatin fiber can be generated by twisting the ribbon.

MeSH Terms
Animals Chick Embryo Chromatin/ultrastructure DNA/analysis DNA, Circular Erythrocytes/ultrastructure Histones Mathematics Microscopy, Electron Models, Molecular Nucleic Acid Conformation Nucleosomes/ultrastructure
Chemicals
Chromatin DNA, Circular Histones Nucleosomes DNA
Authors & Affiliations
3 authors, click to expand affiliations / ORCID
Worcel A
Strogatz S
Riley D
References (41)
41 references, click to expand
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Article Info
Journal
Proceedings of the National Academy of Sciences of the United States of America
Abbr.
Proc Natl Acad Sci U S A
ISSN
0027-8424
DOI
10.1073/pnas.78.3.1461
Published
1981-03-00
Pages
1461-5
Language
English
Region
United States
NLM ID
7505876
PMCID
PMC319150
Subset
IM
External Links
PubMed source DOI: 10.1073/pnas.78.3.1461 PMC Full Text View journal details
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