Shape of ocr, the gene 0.3 protein of bacteriophage T7: Modeling based on light scattering experiments
Shape of ocr, the gene 0.3 protein of bacteriophage T7: Modeling based on light scattering experiments
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DOI：
10.1021/bi010587
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发表时间：
2001-08-21
期刊：
影响因子：
2.9
通讯作者：
Poon, WCK
中科院分区：
文献类型：
--
作者：
Blackstock, JJ;Egelhaaf, SU;Poon, WCK
Ocr是T7噬菌体表达的第一种蛋白质，通过阻止I型DNA限制酶与DNA结合来抑制它们。这种抑制作用使噬菌体能够成功感染宿主。光致变色的形状是建立在静态和动态光散射测量的基础上的。静态光散射数据证实了以前的观察，ocr存在于溶液中的二聚体。动态光散射测定的扩散常数表明ocr二聚体的非球形形状。提出了椭球体的流体动力学模型，并认为ocr最好用一个尺寸为10.4 × 2.6 mn的长椭球体来描述。该模型预测的大小和形状与ocr作为I型限制性内切酶结合的DNA结构的模拟物是一致的。
Ocr, the first protein expressed by bacteriophage T7, inhibits type I DNA restriction enzymes by preventing them from binding to DNA. This inhibition allows the phage to successfully infect the host. The shape of ocr is modeled on the basis of static and dynamic light scattering measurements. The static light scattering data confirm previous observations that ocr exists in solution as a dimer. The diffusion constant determined by dynamic light scattering indicates a nonspherical shape of the ocr dimer. Hydrodynamic models of ellipsoids are presented, and it is argued that ocr is best described by a prolate ellipsoid with dimensions of 10.4 run by 2.6 mn. The size and shape predicted by this model are consistent with ocr acting as a mimic of the DNA structure bound by type I restriction enzymes.