Basic RGB

来自美国加州大学伯克利分校的Carlos Bustamante实验室发现-同效环ATPase中亚基的高度协作和分工,这篇文章刊登在最新一期《CELL》杂志上。

-2012年11月21日《细胞》


中文翻译


【题目】同效环ATPase中亚基的高度协作和分工

【译文】ASCE超家族的环NTPases展现了细胞功能的多样性。但是关于这些分子机制的操作还存在一个重要的问题:这个环亚基是如何协调这些化学和机械转变的。本研究证明了同效环ATPase的综合机械化学特点——噬菌体φ29的“组装马达”作为一种同型五聚体在交替的静息和爆发循环中转移双链DNA。我们利用高分辨率的光学镊子验证这一循环中核苷酸类似物的影响。我们发现在突发期间ATP水解作用连续发生并且在停留期间ADP的释放与ATP的结合交替发生,这反应了在环亚基中高度的协同作用。此外,我们发现了这个“马达”具有意想不到的分工作用:尽管五聚体的所有亚基在每个循环期间都结合在水解ATP上,但仅有4个参与到易位过程,剩余的1个亚基具有ATP依赖性的调节作用。

英文原稿


[Title]High Degree of Coordination and Division of Labor among Subunits in a Homomeric Ring ATPase

[author]Gheorghe Chistol, Shixin Liu, Craig L. Hetherington, Jeffrey R. Moffitt, Shelley Grimes, Paul J. Jardine, Carlos Bustamante

[Abstract]Ring NTPases of the ASCE superfamily perform a variety of cellular functions. An important question about the operation of these molecular machines is how the ring subunits coordinate their chemical and mechanical transitions. Here, we present a comprehensive mechanochemical characterization of a homomeric ring ATPase—the bacteriophage φ29 packaging motor—a homopentamer that translocates double-stranded DNA in cycles composed of alternating dwells and bursts. We use high-resolution optical tweezers to determine the effect of nucleotide analogs on the cycle. We find that ATP hydrolysis occurs sequentially during the burst and that ADP release is interlaced with ATP binding during the dwell, revealing a high degree of coordination among ring subunits. Moreover, we show that the motor displays an unexpected division of labor: although all subunits of the homopentamer bind and hydrolyze ATP during each cycle, only four participate in translocation, whereas the remaining subunit plays an ATP-dependent regulatory role.

原文地址

http://www.cell.com/abstract/S0092-8674(12)01292-5

本站声明: 生物文库所有文章欢迎转载,所有文章未说明,均属于原创,转载均请注明出处。
本文链接: http://www.bioku.cn/201301/cell-superfamily-translocation-homopentamer/
版权所有: 生物文库 - 生物医学、生物技术核心期刊文摘

留言


六 + = 7


沪ICP备12028140号
点击这里给我发消息   点击这里给我发消息