核蛋白颗粒的HMG 14/17结合亲和力及DNA酶I敏感性

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

作者信息

Stein A, Townsend T

出版信息

Nucleic Acids Res. 1983 Oct 11;11(19):6803-19. doi: 10.1093/nar/11.19.6803.

DOI:10.1093/nar/11.19.6803

PMID:6226937

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC326415/

Abstract

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.

摘要

我们发现，普通（整体）鸡红细胞核小体与高迁移率族（HMG）蛋白14/17结合时，被DNA酶I消化得更快。在对照核小体中的DNA被消化至酸溶性为10%至20%的条件下，HMG 14/17-核小体复合物的消化导致长度大于80个核苷酸的单链DNA片段相对于对照核小体产生的DNA片段有特定程度的减少。此外，我们表明，H1/H5缺失染色质经葡萄球菌核酸酶消化后，含有一类丰富的核小体亚类，而天然染色质消化产物中不存在大量此类核小体。这些核小体含有更长的DNA片段，并且电泳迁移率比核心颗粒低。HMG 14/17高度优先地与这些核小体结合，并使其对DNA酶I敏感，这与活性核小体的情况类似。