Differential association of HMG1 and linker histones B4 and H1 with dinucleosomal DNA: structural transitions and transcriptional repression.
Differential association of HMG1 and linker histones B4 and H1 with dinucleosomal DNA: structural transitions and transcriptional repression.
复制标题
HMG1 和接头组蛋白 B4 和 H1 与双核小体 DNA 的差异关联：结构转变和转录抑制。
作者：
Kiyoe Ura;Karl Nightingale;Alan P. Wolffe
我们研究了将组蛋白H1、组蛋白B4或HMG1掺入含有两个5S rRNA基因的合成二核小体的结构和功能后果。我们发现这三种蛋白质都与连接物DNA结合，从微球菌核酸酶消化中稳定了额外的20bp，并限制了核小体的移动。组蛋白H1与二核小体的亲和力最高；组蛋白B4和HMG1的亲和力显著降低。我们发现，组蛋白H1与二核小体模板结合的解离常数(Kd)为7.4 nM，而组蛋白B4和HMG1的解离常数分别为45 nM和300 nM。这些蛋白质与裸露DNA相互作用的Kds分别为：H1 18 nM，B4 80 nM，HMG1 300 nM。这些蛋白质与二核小体结合的差异反映在不同蛋白质抑制5S rRNA基因转录的效率上。因此，虽然这三种蛋白质都有助于染色质的组织，但它们组装的结构的稳定性会有所不同。我们的结果为非洲爪哇早期胚胎染色质的转录混乱提供了分子解释，它富含HMG1和连接子组蛋白B4，但缺乏组蛋白H1。
We examined the structural and functional consequences of incorporating either histone H1, histone B4 or HMG1 into a synthetic dinucleosome containing two 5S rRNA genes. We found that all three proteins bind to linker DNA, stabilizing an additional 20 bp from micrococcal nuclease digestion and restrict nucleosome mobility. Histone H1 has the highest‐affinity interaction with the dinucleosome; histone B4 and HMG1 associate with significantly reduced affinities. We found that histone H1 binds to the dinucleosome template with a dissociation constant (KD) of 7.4 nM, whereas the KD is 45 nM for histone B4 and 300 nM for HMG1. The KDs for the interaction of these proteins with naked DNA are 18 nM for H1, 80 nM for B4 and 300 nM for HMG1. The differences in association of these proteins with the dinucleosome are reflected in the efficiency with which the different proteins repress transcription from the 5S rRNA genes. Thus, although all three proteins can contribute to the organization of chromatin, the stability of the structures they assemble will vary. Our results provide a molecular explanation for the transcriptional promiscuity of Xenopus early embryonic chromatin, which is enriched in HMG1 and linker histone B4, but deficient in histone H1.
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影响因子：
10.5
作者：
PAULL, TT;HAYKINSON, MJ;JOHNSON, RC
通讯作者：
JOHNSON, RC
组蛋白 H1 和 H5 及其球状结构域与四路连接 DNA 的结合。
DOI：
10.1073/pnas.91.9.3525
发表时间：
1994
影响因子：
11.1
作者：
Varga-Weisz,P;Zlatanova,J;Leuba,SH;Schroth,GP;vanHolde,K
通讯作者：
vanHolde,K
影响因子：
10.5
作者：
SHYKIND, BM;KIM, J;SHARP, PA
通讯作者：
SHARP, PA
高富集高迁移率基团蛋白 HMG 1 和 HMG 2 的核小体的圆二色性、热变性和脱氧核糖核酸酶 I 消化研究。
影响因子：
2.9
作者：
Jackson,JB;Rill,RL
通讯作者：
Rill,RL