Assembly of single chromatin fibers depends on the tension in the DNA molecule: magnetic tweezers study.
We have used magnetic tweezers to study in real time chaperone-mediated chromatin assembly/disassembly at the level of single chromatin fibers. We find a strong dependence of the rate of assembly on the exerted force, with strong inhibition of assembly at forces exceeding 10 pN. During assembly, and especially at higher forces, occasional abrupt increases in the length of the fiber were observed, giving a clear indication of reversibility of the assembly process. This result is a clear demonstration of the dynamic equilibrium between nucleosome assembly and disassembly at the single chromatin fiber level.
Leuba
Sanford H
SH
Department of Cell Biology and Physiology, School of Medicine, Hillman Cancer Center, University of Pittsburgh Cancer Institute Research Pavilion, Pittsburgh, PA 15213, USA. leuba@pitt.edu
Karymov
Mikhail A
MA
Tomschik
Miroslav
M
Ramjit
Ravi
R
Smith
Paul
P
Zlatanova
Jordanka
J
D002843:Chromatin / Q000737:chemistry*; D004247:DNA / Q000737:chemistry*; D008280:Magnetics; D018625:Microscopy, Atomic Force; D009707:Nucleosomes / Q000737:chemistry
D002843:Chromatin; D009707:Nucleosomes; D004247:DNA