DNase I footprinting of the nucleosome in whole nuclei.
DNase I was used to footprint the 147 bp DNA fragment of the nucleosome in whole chicken erythrocyte nuclei. It was found that the higher-order structure imposes an additional protection on nucleosomes at sites close to the entry and exit points of the linker DNA, around the dyad axis (site S 0). The observed protection is extended up to 20 bp on either side of S 0. It is partial (approximately 50%) and most probably reflects a full protection of different regions in alternatively oriented nucleosomes. These are the same regions which interact with linker histones. The results strongly support the findings by simulation of DNase I digests of unlabelled oligonucleosome fragments in the 30 nm fibre that in all nucleosomes sites S -5 to S -3 and S +3 to S +5 ara on the outside of the fibre exposed to DNase I.
Staynov
D Z
DZ
Imperial College London, National Heart and Lung Institute, Royal Brompton Campus, Guy Scadding Building, Dovehouse Street, London SW3 6LY, UK. d.staynov@imperial.ac.uk
D000818:Animals; D002467:Cell Nucleus / Q000737:chemistry*; D002645:Chickens; D004247:DNA / Q000737:chemistry; D018983:DNA Footprinting; D003850:Deoxyribonuclease I / Q000737:chemistry*; D004912:Erythrocytes / Q000737:chemistry / Q000648:ultrastructure; D009690:Nucleic Acid Conformation; D009707:Nucleosomes / Q000737:chemistry*
D009707:Nucleosomes; D004247:DNA; D003850:Deoxyribonuclease I