Fast Kinetics of Chromatin Assembly Revealed by Single-Molecule Videomicroscopy and Scanning Force Microscopy

Fluorescence videomicroscopy and scanning force microscopy were used to follow, in real time, chromatin assembly on individual DNA molecules immersed in cell-free systems competent for physiological chromatin assembly. Within a few seconds, molecules are already compacted into a form exhibiting stro...

Full description

Saved in:
Bibliographic Details
Published in:Proceedings of the National Academy of Sciences - PNAS 2000-12, Vol.97 (26), p.14251-14256
Main Authors: Ladoux, B, Quivy, J P, Doyle, P, du Roure, O, Almouzni, G, Viovy, J L
Format: Article
Language:English
Subjects:
Animals
Bacteriophage lambda - genetics
Biological Sciences
Biology
Cell Extracts
Chromatin
Chromatin - metabolism
Deoxyribonucleic acid
Dimers
DNA
DNA, Viral - metabolism
Drosophila
Eggs
Flow velocity
Fluorescence
Histones
Kinetics
Microscopy
Microscopy, Atomic Force - methods
Microscopy, Video - methods
Models, Molecular
Molecules
Nucleosomes
Nucleosomes - metabolism
Physics
Scientific imaging
Time Factors
Video
Xenopus
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Fluorescence videomicroscopy and scanning force microscopy were used to follow, in real time, chromatin assembly on individual DNA molecules immersed in cell-free systems competent for physiological chromatin assembly. Within a few seconds, molecules are already compacted into a form exhibiting strong similarities to native chromatin fibers. In these extracts, the compaction rate is more than 100 times faster than expected from standard biochemical assays. Our data provide definite information on the forces involved (a few piconewtons) and on the reaction path. DNA compaction as a function of time revealed unique features of the assembly reaction in these extracts. They imply a sequential process with at least three steps, involving DNA wrapping as the final event. An absolute and quantitative measure of the kinetic parameters of the early steps in chromatin assembly under physiological conditions could thus be obtained.
ISSN:0027-8424
1091-6490
DOI:10.1073/pnas.250471597