Function of a viral genome packaging motor from bacteriophage T4 is insensitive to DNA sequence.
Function of a viral genome packaging motor from bacteriophage T4 is insensitive to DNA sequence.
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DOI：
10.1093/nar/gkaa875
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发表时间：
2020-11-18
影响因子：
14.9
通讯作者：
Smith DE
中科院分区：
文献类型：
--
作者：
Mo Y;Keller N;delToro D;Ananthaswamy N;Harvey SC;Rao VB;Smith DE
许多病毒在组装过程中使用ATP驱动的马达将DNA转移到原衣壳壳中。之前的报道提出了运动功能是否受底物DNA序列调节的问题：（i）噬菌体T4运动表现出较大的移位率波动、暂停和滑动;（ii）证据表明噬菌体phi 29运动在移位过程中接触DNA碱基;以及（iii）一种理论模型，“B-A scrunchworm”，预测更容易转变为A型的“A-嗜性”序列将改变运动功能。在这里，我们使用单分子光镊测量比较易位的噬菌体，质粒，和合成的A-嗜，GC丰富的序列的T4电机。我们没有观察到运动速度的显着差异，即使与嗜A序列预测显示较高的易位率在高施加的力。我们还观察到运动暂停没有显著变化，而滑动只有适度的变化。为了更普遍地测试序列依赖性，我们对成对的包装事件进行了相关性分析。包装率，暂停或滑动与序列位置之间没有显着的相关性，检测到在几个不同的DNA序列的重复测量。这些研究表明，病毒基因组包装是不敏感的DNA序列和包装电机速度的波动，暂停和滑动主要是随机的时间事件。
Many viruses employ ATP-powered motors during assembly to translocate DNA into procapsid shells. Previous reports raise the question if motor function is modulated by substrate DNA sequence: (i) the phage T4 motor exhibits large translocation rate fluctuations and pauses and slips; (ii) evidence suggests that the phage phi29 motor contacts DNA bases during translocation; and (iii) one theoretical model, the ‘B-A scrunchworm’, predicts that ‘A-philic’ sequences that transition more easily to A-form would alter motor function. Here, we use single-molecule optical tweezers measurements to compare translocation of phage, plasmid, and synthetic A-philic, GC rich sequences by the T4 motor. We observed no significant differences in motor velocities, even with A-philic sequences predicted to show higher translocation rate at high applied force. We also observed no significant changes in motor pausing and only modest changes in slipping. To more generally test for sequence dependence, we conducted correlation analyses across pairs of packaging events. No significant correlations in packaging rate, pausing or slipping versus sequence position were detected across repeated measurements with several different DNA sequences. These studies suggest that viral genome packaging is insensitive to DNA sequence and fluctuations in packaging motor velocity, pausing and slipping are primarily stochastic temporal events.
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影响因子：
4
作者：
delToro, Damian;Smith, Douglas E.
通讯作者：
Smith, Douglas E.
影响因子：
14.9
作者：
Fuller, DN;Gemmen, GJ;Smith, DE
通讯作者：
Smith, DE
影响因子：
3.4
作者：
Berndsen, Zachary T.;Keller, Nicholas;Smith, Douglas E.
通讯作者：
Smith, Douglas E.
DOI：
10.1073/pnas.0704008104
发表时间：
2007-10-23
影响因子：
11.1
作者：
Fuller, Derek N.;Raymer, Dorian M.;Smith, Douglas E.
通讯作者：
Smith, Douglas E.
DOI：
10.1007/978-1-4614-0980-9_24
发表时间：
2012-01-01
期刊：
VIRAL MOLECULAR MACHINES
影响因子：
--
作者：
Chemla, Yann R.;Smith, Douglas E.
通讯作者：
Smith, Douglas E.