Nucleosome core particles suppress the thermal untwisting of core DNA and adjacent linker DNA.
Covalently closed circular DNA is known to undergo a temperature-dependent change in helical twist. We have reconstituted nucleosome core particles onto closed circular DNA and measured the thermal untwisting of the DNA as a function of nucleosome density. The results demonstrate that the DNA associated with the nucleosome core particle does not alter its twist when the temperature is varied between 4 degrees C and 37 degrees C, and that the length of DNA prevented from thermal untwisting includes the linker as well as the core DNA.
D000818:Animals; D002645:Chickens; D004247:DNA / Q000097:blood*; D004591:Electrophoresis, Polyacrylamide Gel; D004912:Erythrocytes / Q000378:metabolism; D009690:Nucleic Acid Conformation; D009707:Nucleosomes / Q000378:metabolism* / Q000648:ultrastructure; D010957:Plasmids; D013696:Temperature; D013816:Thermodynamics
D009707:Nucleosomes; D004247:DNA