Structure of Ocr from bacteriophage T7, a protein that mimics B-form DNA
Structure of Ocr from bacteriophage T7, a protein that mimics B-form DNA
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DOI：
10.1016/s1097-2765(02)00435-5
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发表时间：
2002-01-01
期刊：
影响因子：
16
通讯作者：
Dryden, DTF
中科院分区：
文献类型：
--
作者：
Walkinshaw, MD;Taylor, P;Dryden, DTF
我们已经解决了，通过X射线晶体学的分辨率为1.8埃，蛋白质的结构能够模仿大约20个碱基对的B型DNA。这种ocr蛋白由噬菌体T7的基因0.3编码，模拟弯曲DNA分子的大小和形状，以及沿B型DNA磷酸骨架沿着的负电荷排列。我们还表明，ocr是一种有效的抑制剂，在体内的所有已知的家庭复杂的I型DNA限制酶。使用原子力显微镜，我们还观察到I型酶诱导DNA的弯曲，其幅度与ocr分子的弯曲相似。抗限制性蛋白的第一个结构证明了B型DNA长片段的结构模拟物的构建。
We have solved, by X-ray crystallography to a resolution of 1.8 Angstrom, the structure of a protein capable of mimicking approximately 20 base pairs of B-form DNA. This ocr protein, encoded by gene 0.3 of bacteriophage T7, mimics the size and shape of a bent DNA molecule and the arrangement of negative charges along the phosphate backbone of B-form DNA. We also demonstrate that ocr is an efficient inhibitor in vivo of all known families of the complex type I DNA restriction enzymes. Using atomic force microscopy, we have also observed that type I enzymes induce a bend in DNA of similar magnitude to the bend in the ocr molecule. This first structure of an antirestriction protein demonstrates the construction of structural mimetics of long segments of B-form DNA.