Single-molecule studies of repressor-DNA interactions show long-range interactions
Single-molecule studies of repressor-DNA interactions show long-range interactions
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DOI：
10.1073/pnas.0502917102
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发表时间：
2005-07-12
影响因子：
11.1
通讯作者：
Austin, RH
中科院分区：
文献类型：
--
作者：
Wang, YM;Tegenfeldt, JO;Austin, RH
我们进行了GFP-Lacl抑制蛋白与噬菌体A DNA结合的单分子研究，其中含有256个串联lac操作符插入，限制在纳米通道中。开发了一种集成光子分子计数方法来测定与DNA结合的蛋白质数量。通过使用该方法，我们确定256家串联lac运营商的饱和平均占用率为13，仅占可用站点的2.5%。这种低占用率表明，即使阻遏物相隔很远，相距200纳米或几个DNA持续长度，它们也会相互影响。
We have performed single-molecule studies of GFP-Lacl repressor proteins bound to bacteriophage A DNA containing a 256 tandem lac operator insertion confined in nanochannels. An integrated photon molecular counting method was developed to determine the number of proteins bound to DNA. By using this method, we determined the saturated mean occupancy of the 256 tandem lac operators to be 13, which constitutes only 2.5% of the available sites. This low occupancy level suggests that the repressors influence each other even when they are widely separated, at distances on the order of 200 nm, or several DNA persistence lengths.