HMG 14/17 binding affinities and DNAase I sensitivities of nucleoprotein particles.

AUTOR(ES)

Stein, A

RESUMO

We show that ordinary (bulk) chicken erythrocyte nucleosomes are digested more rapidly by DNAase I when they are associated with high mobility group (HMG) proteins 14/17. Digestion of HMG 14/17-nucleosome complexes, under conditions where the DNA in control nucleosomes is digested to 10 to 20% acid solubility, results in a particular depletion of single-strand DNA fragments greater than 80 nucleotides in length, relative to the DNA fragments produced from control nucleosomes. Additionally, we show that staphylococcal nuclease digests of H1/H5-depleted chromatin contain an abundant subclass of nucleosomes that are not present in appreciable amounts in digests of native chromatin. These nucleosomes contain longer lengths of DNA and have lower electrophoretic mobilities than core particles. HMG 14/17 associates highly preferentially with these nucleosomes and renders them sensitive to DNAase I, similar to what has been found for active nucleosomes.

Documentos Relacionados

• Histone H1 and HMG 14/17 are deposited nonrandomly in the nucleus.
• Partitioning of zinc and copper within subnuclear nucleoprotein particles.
• Distribution of high mobility group proteins 1/2, E and 14/17 and linker histones H1 and H5 on transcribed and non-transcribed regions of chicken erythrocyte chromatin.
• Recombinant human chromosomal proteins HMG-14 and HMG-17.
• The characterisation of 1SF monomer nucleosomes from hen oviduct and the partial characterisation of a third HMG14/17-like in such nucleosomes.