Chemical evidence that chromatin DNA exists as 160 base pair beads interspersed with 40 base pair bridges
- 1 January 1976
- journal article
- Published by Oxford University Press (OUP) in Nucleic Acids Research
- Vol. 3 (1) , 117-128
- https://doi.org/10.1093/nar/3.1.117
Abstract
Digestion of rat liver nuclei by an endogenous endonuclease generates double-stranded DNA fragments which are initially about 205 base pairs long, as reported previously by Hewish and Burgoyne. As digestion proceeds, the average size of these fragments is reduced to about 160 base pairs. Electrophoresis under denaturing conditions shows that these DNA fragments contain single strand nicks at ten base intervals. Fifteen bands, 10-150 bases, are clearly resolvable. DNA Fragments of 160 to 200 nucleotides are not resolved as distinct species. The results suggest that the chromosomal subunit contains both a 160 base-pair DNA segment, in a conformation susceptible to single strand nicking at ten base intervals, and a forty base-pair DNA segment in a conformation more uniformly susceptible to endogenous endonuclease activity. This chemical evidence agrees with morphological observations suggesting that chromatin has a "bead and bridge" structure.Keywords
This publication has 18 references indexed in Scilit:
- Chromatin sub-structure. The digestion of chromatin DNA at regularly spaced sites by a nuclear deoxyribonucleasePublished by Elsevier ,2004
- Comparison of the digestion of nuclei and chromatin by staphylococcal nucleaseBiochemistry, 1975
- Electron microscopic and biochemical evidence that chromatin structure is a repeating unitCell, 1975
- Preparation of Native Chromatin and Damage Caused by ShearingScience, 1975
- Chromatin Structure: Deduced from a MinichromosomeScience, 1975
- Electron microscopy of chromatin subunit particlesBiochemical and Biophysical Research Communications, 1974
- Subunit structure of chromatinNature, 1974
- Hemophilus aegyptius restriction endonuclease cleavage map of the simian virus 40 genome and its colinear relation with the Hemophilus influenzae cleavage map of SV40Journal of Molecular Biology, 1974
- Spheroid Chromatin Units (ν Bodies)Science, 1974
- ISOLATION OF NUCLEI FROM MAMMALIAN TISSUES THROUGH THE USE OF TRITON X-100Journal of Histochemistry & Cytochemistry, 1964