DNase I digestion reveals alternating asymmetrical protection of the nucleosome by the higher order chromatin structure.

ABSTRACT: DNase I was used to probe the higher order chromatin structure in whole nuclei. The digestion profiles obtained were the result of single-stranded cuts and were independent of pH, type of divalent ion and chromatin repeat length. Furthermore, the protection from digestion of the DNA at the entry/exit points on the nucleosome was found to be caused not by the H1/H5 histone tails, but by the compact structure that these proteins support. In order to resolve symmetry ambiguities, DNase I digestion fragments over several nucleosome repeat lengths were analysed quantitatively and compared with computer simulations using combinations of the experimentally obtained rate constants (some of which were converted to 0 to simulate steric protection from DNase I digestion). A clear picture of precisely

SUBMITTER: Staynov DZ 

PROVIDER: S-EPMC108430 | biostudies-literature | 2000 Aug

REPOSITORIES: biostudies-literature