Structural insights into the interaction of the crenarchaeal chromatin protein Cren7 with DNA
Structural insights into the interaction of the crenarchaeal chromatin protein Cren7 with DNA
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洞口染色质蛋白 Cren7 与 DNA 相互作用的结构见解
DOI：
10.1111/j.1365-2958.2010.07136.x
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发表时间：
2010-05-01
影响因子：
3.6
通讯作者：
Huang, Li
中科院分区：
文献类型：
--
作者：
Zhang, Zhenfeng;Gong, Yong;Huang, Li
Cren 7是一种新发现的染色质蛋白，在泉古菌中高度保守。该蛋白对双链DNA的亲和力高于对单链DNA的亲和力，在体外抑制负DNA超螺旋，在体内与基因组DNA相关。在这里，我们报告的晶体结构的Cren 7蛋白从硫磺硫化叶菌在复杂的两个DNA序列。Cren 7结合在DNA的小沟中，并通过插入Leu 28的疏水侧链在DNA中引起单步尖锐扭结（类似于53度）。Cren 7的β 3-β 4环在蛋白质与DNA结合后发生显着的构象变化，表明其在蛋白质-DNA复合物的稳定中发挥着关键作用。DNA接触氨基酸残基在稳定Cren 7-DNA相互作用中的作用通过突变分析来检查。Cren 7-DNA复合物与Sac 7 d-DNA复合物的结构比较揭示了两种蛋白质在DNA结合表面上的显着差异，表明Cren 7和Sul 7 d在染色体组织中具有不同的功能。
P>Cren7, a newly found chromatin protein, is highly conserved in the Crenarchaeota. The protein shows higher affinity for double-stranded DNA than for single-stranded DNA, constrains negative DNA supercoils in vitro and is associated with genomic DNA in vivo. Here we report the crystal structures of the Cren7 protein from Sulfolobus solfataricus in complex with two DNA sequences. Cren7 binds in the minor groove of DNA and causes a single-step sharp kink in DNA (similar to 53 degrees) through the intercalation of the hydrophobic side chain of Leu28. Loop beta 3-beta 4 of Cren7 undergoes a significant conformational change upon binding of the protein to DNA, suggesting its critical role in the stabilization of the protein-DNA complex. The roles of DNA-contacting amino acid residues in stabilizing the Cren7-DNA interaction were examined by mutational analysis. Structural comparison of Cren7-DNA complexes with Sac7d-DNA complexes reveals significant differences between the two proteins in DNA binding surface, suggesting that Cren7 and Sul7d serve distinct functions in chromosomal organization.