Click here to close Hello! We notice that you are using Internet Explorer, which is not supported by Echinobase and may cause the site to display incorrectly. We suggest using a current version of Chrome, FireFox, or Safari.
Echinobase
ECB-ART-37471
Biophys J 2000 Jul 01;791:584-94. doi: 10.1016/S0006-3495(00)76318-1.
Show Gene links Show Anatomy links

Salt-dependent compaction of di- and trinucleosomes studied by small-angle neutron scattering.

Hammermann M , Tóth K , Rodemer C , Waldeck W , May RP , Langowski J .


???displayArticle.abstract???
Using small-angle neutron scattering (SANS), we have measured the salt-dependent static structure factor of di- and trinucleosomes from chicken erythrocytes and from COS-7 cells. We also determined the sedimentation coefficients of these dinucleosomes and dinucleosomes reconstituted on a 416-bp DNA containing two nucleosome positioning sequences of the 5S rDNA of Lytechinus variegatus at low and high salt concentrations. The internucleosomal distance d was calculated by simulation as well as Fourier back-transformation of the SANS curves and by hydrodynamic simulation of sedimentation coefficients. Nucleosome dimers from chicken erythrocyte chromatin show a decrease in d from approximately 220 A at 5 mM NaCl to 150 A at 100 mM NaCl. For dinucleosomes from COS-7 chromatin, d decreases from 180 A at 5 mM to 140 A at 100 mM NaCl concentration. Our measurements on trinucleosomes are compatible with a compaction through two different mechanisms, depending on the salt concentration. Between 0 and 20 mM NaCl, the internucleosomal distance between adjacent nucleosomes remains constant, whereas the angle of the DNA strands entering and leaving the central nucleosome decreases. Above 20 mM NaCl, the adjacent nucleosomes approach each other, similar to the compaction of dinucleosomes. The internucleosomal distance of 140-150 A at 100 mM NaCl is in agreement with distances measured by scanning force microscopy and electron microscopy on long chromatin filaments.

???displayArticle.pubmedLink??? 10866982
???displayArticle.pmcLink??? PMC1300960
???displayArticle.link??? Biophys J


Genes referenced: LOC579984

References [+] :
Bednar, Chromatin conformation and salt-induced compaction: three-dimensional structural information from cryoelectron microscopy. 1995, Pubmed