Linked Life Data

20858435

Source:http://linkedlifedata.com/resource/pubmed/id/20858435

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2010-9-22
pubmed:abstractText
The physical mechanism of the folding and unfolding of chromatin is fundamentally related to transcription but is incompletely characterized and not fully understood. We experimentally and theoretically studied chromatin compaction by investigating the salt-mediated folding of an array made of 12 positioning nucleosomes with 177 bp repeat length. Sedimentation velocity measurements were performed to monitor the folding provoked by addition of cations Na(+), K(+), Mg(2+), Ca(2+), spermidine(3+), Co(NH(3))(6)(3+), and spermine(4+). We found typical polyelectrolyte behavior, with the critical concentration of cation needed to bring about maximal folding covering a range of almost five orders of magnitude (from 2 ?M for spermine(4+) to 100 mM for Na(+)). A coarse-grained model of the nucleosome array based on a continuum dielectric description and including the explicit presence of mobile ions and charged flexible histone tails was used in computer simulations to investigate the cation-mediated compaction. The results of the simulations with explicit ions are in general agreement with the experimental data, whereas simple Debye-Hückel models are intrinsically incapable of describing chromatin array folding by multivalent cations. We conclude that the theoretical description of the salt-induced chromatin folding must incorporate explicit mobile ions that include ion correlation and ion competition effects.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
1542-0086
pubmed:author
pubmed:copyrightInfo
Copyright © 2010 Biophysical Society. Published by Elsevier Inc. All rights reserved.
pubmed:issnType
Electronic
pubmed:day
22
pubmed:volume
99
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1896-905
pubmed:dateRevised
2011-9-23
pubmed:meshHeading
pubmed:year
2010
pubmed:articleTitle
Electrostatic origin of salt-induced nucleosome array compaction.
pubmed:affiliation
School of Biological Sciences, Nanyang Technological University, Singapore.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't