Archaeal Chromatin Proteins Cren7 and Sul7d Compact DNA by Bending and Bridging
Archaeal Chromatin Proteins Cren7 and Sul7d Compact DNA by Bending and Bridging
复制标题
通过弯曲和桥接古细菌染色质蛋白 Cren7 和 Sul7d 紧凑 DNA
作者：
Zhang Zhenfeng;Zhan Zhengyan;Wang Bing;Chen Yuanyuan;Chen Xiuqiang;Wan Cuihong;Fu Yu;Huang Li
一个长期存在的问题是，染色体DNA是如何在古生菌的一个主要类群--克伦考古塔中包装的，它能合成大量独特的小DNA结合蛋白，但通常不包含古菌组蛋白。在目前的工作中，我们验证了我们的假设，即两个研究得很好的古生菌染色质蛋白Cren7和Sul7d通过DNA弯曲和桥接使DNA紧凑。我们证明了这两种蛋白质能够在单分子水平上压缩DNA，尽管效率不同，方式也不同。我们首次证明了这两种蛋白质，长期以来一直被认为是DNA结合剂和弯曲器，能够介导DNA桥接，而这一以前未知的蛋白质属性使DNA能够被包装成高度浓缩的结构。因此，我们的研究结果为研究裸角类染色体DNA组织的机制和动力学提供了有意义的见解。摘要古细菌染色质蛋白Cren7和Sul7d是DNA结合蛋白。为了更好地了解它们在染色体DNA组织中的结构作用，我们利用全单分子内反射荧光显微镜(SM-TIRFM)和原子力显微镜(AFM)在单分子水平上分析了Sulfolobus Island andicus的Cren7和Sis7d家族成员的DNA紧凑作用。我们发现，Cren7和Sis7d都能够在三步过程中将单链的λDNA压缩成高度浓缩的结构，并且在DNA压缩方面，Cren7的效率比Sis7d高一个数量级。这两种蛋白质在DNA弯曲动力学上相似，但在DNA缩合模式上不同。在饱和浓度下，Sis7d形成随机分布的簇，而Cren7在质粒DNA上形成单一的高度浓缩的核心。这一观察结果与Cren7比Sis7d更强的连接DNA的能力是一致的。我们的结果为深入了解新古菌染色体DNA组织的机制和动力学提供了有意义的见解。重要性一个长期存在的问题是，染色体DNA是如何在克伦考古塔中包装的，克伦考古塔是古生菌的一个主要群体，它合成大量独特的小DNA结合蛋白，但通常不包含古生物组蛋白。在目前的工作中，我们验证了我们的假设，即两个研究得很好的古生菌染色质蛋白Cren7和Sul7d通过DNA弯曲和桥接使DNA紧凑。我们证明了这两种蛋白质能够在单分子水平上压缩DNA，尽管效率不同，方式也不同。我们首次证明了这两种蛋白质，长期以来一直被认为是DNA结合剂和弯曲器，能够介导DNA桥接，而这一以前未知的蛋白质属性使DNA能够被包装成高度浓缩的结构。因此，我们的研究结果为研究裸角类染色体DNA组织的机制和动力学提供了有意义的见解。
A long-standing question is how chromosomal DNA is packaged in Crenarchaeota, a major group of archaea, which synthesize large amounts of unique small DNA-binding proteins but in general contain no archaeal histones. In the present work, we tested our hypothesis that the two well-studied crenarchaeal chromatin proteins Cren7 and Sul7d compact DNA by both DNA bending and bridging. We show that the two proteins are capable of compacting DNA, albeit with different efficiencies and in different manners, at the single molecule level. We demonstrate for the first time that the two proteins, which have long been regarded as DNA binders and benders, are able to mediate DNA bridging, and this previously unknown property of the proteins allows DNA to be packaged into highly condensed structures. Therefore, our results provide significant insights into the mechanism and kinetics of chromosomal DNA organization in Crenarchaeota. ABSTRACT Archaeal chromatin proteins Cren7 and Sul7d from Sulfolobus are DNA benders. To better understand their architectural roles in chromosomal DNA organization, we analyzed DNA compaction by Cren7 and Sis7d, a Sul7d family member, from Sulfolobus islandicus at the single-molecule (SM) level by total single-molecule internal reflection fluorescence microscopy (SM-TIRFM) and atomic force microscopy (AFM). We show that both Cren7 and Sis7d were able to compact singly tethered λ DNA into a highly condensed structure in a three-step process and that Cren7 was over an order of magnitude more efficient than Sis7d in DNA compaction. The two proteins were similar in DNA bending kinetics but different in DNA condensation patterns. At saturating concentrations, Sis7d formed randomly distributed clusters whereas Cren7 generated a single and highly condensed core on plasmid DNA. This observation is consistent with the greater ability of Cren7 than of Sis7d to bridge DNA. Our results offer significant insights into the mechanism and kinetics of chromosomal DNA organization in Crenarchaea. IMPORTANCE A long-standing question is how chromosomal DNA is packaged in Crenarchaeota, a major group of archaea, which synthesize large amounts of unique small DNA-binding proteins but in general contain no archaeal histones. In the present work, we tested our hypothesis that the two well-studied crenarchaeal chromatin proteins Cren7 and Sul7d compact DNA by both DNA bending and bridging. We show that the two proteins are capable of compacting DNA, albeit with different efficiencies and in different manners, at the single molecule level. We demonstrate for the first time that the two proteins, which have long been regarded as DNA binders and benders, are able to mediate DNA bridging, and this previously unknown property of the proteins allows DNA to be packaged into highly condensed structures. Therefore, our results provide significant insights into the mechanism and kinetics of chromosomal DNA organization in Crenarchaeota.
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影响因子：
10.5
作者：
Graham TG;Wang X;Song D;Etson CM;van Oijen AM;Rudner DZ;Loparo JJ
通讯作者：
Loparo JJ
DOI：
10.1101/065664
发表时间：
2016-07
期刊：
bioRxiv
影响因子：
--
作者：
C. Brackley;B. Liebchen;D. Michieletto;Francois Mouvet;P. Cook;D. Marenduzzo
通讯作者：
C. Brackley;B. Liebchen;D. Michieletto;Francois Mouvet;P. Cook;D. Marenduzzo
影响因子：
4.8
作者：
Lou, HQ;Duan, ZH;Huang, L
通讯作者：
Huang, L
影响因子：
3.4
作者：
Tafvizi, Anahita;Huang, Fang;van Oijen, Antoine M.
通讯作者：
van Oijen, Antoine M.
DOI：
10.1073/pnas.181029198
发表时间：
2001-09-11
影响因子：
11.1
作者：
Ali, BMJ;Amit, R;Stavans, J
通讯作者：
Stavans, J