当前位置: X-MOL 学术bioRxiv. Biophys. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
A viral genome packaging motor transitions between cyclic and helical symmetry to translocate dsDNA
bioRxiv - Biophysics Pub Date : 2020-06-06 , DOI: 10.1101/2020.05.23.112524
Michael Woodson , Joshua Pajak , Wei Zhao , Wei Zhang , Gaurav Arya , Mark A. White , Paul. J. Jardine , Marc C. Morais

Molecular segregation and biopolymer manipulation require the action of molecular motors to do work by applying directional forces to macromolecules. The additional strand conserved E (ASCE) ring motors are an ancient family of molecular motors responsible for diverse tasks ranging from biological polymer manipulation (e.g. protein degradation and chromosome segregation) to establishing and maintaining proton gradients across mitochondrial membranes. Viruses also utilize ASCE segregation motors to package their genomes into their protein capsids and serve as accessible experimental systems due to their relative simplicity. We show by CryoEM focused image reconstruction that ASCE ATPases in viral dsDNA packaging motors adopt helical symmetry complementary to their dsDNA substrates. Together with previous data, including structural results showing these ATPases in planar ring conformations, our results suggest that these motors cycle between helical and planar cyclical symmetry, providing a possible mechanism for directional translocation of DNA. We further note that similar changes in quaternary structure have been observed for proteasome and helicase motors, suggesting an ancient and common mechanism of force generation that has been adapted for specific tasks over the course of evolution.

中文翻译:

病毒基因组包装运动在周期性和螺旋对称性之间过渡,从而使dsDNA易位

分子分离和生物聚合物的操纵需要分子马达的作用来通过向大分子施加方向力来起作用。附加的链保守E(ASCE)环马达是古老的分子马达家族,负责各种任务,从生物聚合物操纵(例如蛋白质降解和染色体分离)到建立和维持跨线粒体膜的质子梯度。病毒还利用ASCE分离引擎将其基因组包装到它们的蛋白质衣壳中,并且由于其相对简单性而可以作为可访问的实验系统。我们通过CryoEM聚焦图像重建显示,病毒dsDNA包装电机中的ASCE ATPase采用与其dsDNA底物互补的螺旋对称性。连同以前的数据,包括显示这些ATP酶呈平面环构型的结构结果,我们的结果表明这些电机在螺旋和平面循环对称性之间循环,为DNA的方向转移提供了可能的机制。我们进一步注意到,对于蛋白酶体和解旋酶马达,四级结构也发生了类似的变化,这表明古老而又常见的力生成机制已经适应了进化过程中的特定任务。
更新日期:2020-06-06
down
wechat
bug