THE FOOTPRINT OF CHROMOSOMAL-PROTEINS HMG-14 AND HMG-17 ON CHROMATIN SUBUNITS
THE FOOTPRINT OF CHROMOSOMAL-PROTEINS HMG-14 AND HMG-17 ON CHROMATIN SUBUNITS
复制标题
DOI：
10.1006/jmbi.1994.1128
复制
发表时间：
1994-02-11
影响因子：
5.6
通讯作者：
BUSTIN, M
中科院分区：
文献类型：
--
作者：
ALFONSO, PJ;CRIPPA, MP;BUSTIN, M
染色体蛋白HMG-14和HMG-17在核小体核心和缺乏连接体组蛋白的染色体中的位置已经通过羟基自由基足迹法绘制。核小体核心和H1/H5耗尽的染色体都可以特异性结合两个HMG-14/-17分子。HMG-14在染色质亚基表面上的路径与HMG-17的路径不可区分。结合的HMG保护DNA免受羟基自由基切割，所述羟基自由基切割距离位于核小体二分体轴两侧的DNA的两个大沟中的每一个中的核小体核心中的DNA末端25个碱基对。因此，在核心和H1/H5缺失的染色体中，蛋白质桥接颗粒表面上的两条相邻DNA链。HMG在染色体长度颗粒末端附近占据的位点与H1/H5接头组蛋白所占据的位点不同。在二分体轴的区域中，HMG的结合位点与接头组蛋白的结合位点重叠。HMG-14/17在核小体二分体轴附近的位置提高了组蛋白H1和HMG之间的相互作用可能影响染色质的转录潜力的可能性。
The position of chromosomal proteins HMG-14 and HMG-17 in nucleosome cores and in chromatosomes lacking linker histones has been mapped by hydroxyl radical footprinting. Both the nucleosome core and the H1/H5 depleted chromatosome can specifically bind two molecules of HMG-14/-17. The path of HMG-14 on the surface of chromatin subunits is indistinguishable from that of HMG-17. The bound HMGs protect the DNA from hydroxyl radical cleavage 25 base-pairs from the end of the DNA in nucleosome cores in each of the two major grooves of the DNA flanking the nucleosomal dyad axis. Thus, in both cores and H1/H5-depleted chromatosomes the proteins bridge two adjacent DNA strands on the surface of the particles. The sites occupied by HMG near the end of the chromatosome-length particles are distinct from those occupied by the H1/H5 linker histones. In the region of the dyad axis the binding sites of HMGs overlap those of the linker histones. The placement of HMG-14/17 near the nucleosomal dyad axis raises the possibility that interactions between histone H1 and HMGs may affect the transcriptional potential of chromatin.