Structure of the Wilms tumor suppressor protein zinc finger domain bound to DNA
Structure of the Wilms tumor suppressor protein zinc finger domain bound to DNA
复制标题
DOI：
10.1016/j.jmb.2007.07.017
复制
发表时间：
2007-10-05
影响因子：
5.6
通讯作者：
Wright, Peter E.
中科院分区：
文献类型：
--
作者：
Stoll, Raphael;Lee, Brian M.;Wright, Peter E.
Wilms肿瘤抑制蛋白（WT 1）的锌指结构域包含四个典型的Cys（2）His（2）锌指。WT 1优先结合与EGR-1共有位点密切相关的DNA序列。我们报告的结构测定的X射线晶体学和NMR光谱的WT 1锌指结构域与DNA的复合物。确定了具有同源14个碱基对的寡核苷酸的复合物的X射线结构，并且确定了具有14个碱基对和扩展的17个碱基对的DNA的复合物的复合物的X射线/NMR结构。这种组合的方法允许明确的第一个锌指的位置，这是在晶体结构中的晶格接触的影响确定。晶体结构显示第二、第三和第四锌指结构域插入DNA的大沟深处，在那里它们进行碱基特异性相互作用。DNA双链体在第一个锌指附近发生扭曲，胞苷扭曲并倾斜出碱基堆，以挤压手指1和手指2的尖端。相比之下，复合物的X-射线/NMR结构表明，手指我继续遵循的主要槽在溶液中的配合物。然而，螺旋的方向是非规范的，并且螺旋的指尖和N末端伸出大沟;因此，通常参与碱基识别的锌指侧链不与DNA接触。我们的结论是，手指1有助于锚WT 1的DNA通过放大的结合亲和力，虽然它没有显着贡献的结合特异性。这些结构提供了对与Denys-Drash综合征和肾病综合征相关的锌指2和3突变的潜在后果的分子水平的见解。突变有两种类型，要么使锌指结构不稳定，要么取代关键的碱基接触残基。(c)2007爱思唯尔有限公司版权所有。
The zinc finger domain of the Wilms tumor suppressor protein (WT1) contains four canonical Cys(2)His(2) zinc fingers. WT1 binds preferentially to DNA sequences that are closely related to the EGR-1 consensus site. We report the structure determination by both X-ray crystallography and NMR spectroscopy of the WT1 zinc finger domain in complex with DNA. The X-ray structure was determined for the complex with a cognate 14 base-pair oligonucleotide, and composite X-ray/NMR structures were determined for complexes with both the 14 base-pair and an extended 17 base-pair DNA. This combined approach allowed unambiguous determination of the position of the first zinc finger, which is influenced by lattice contacts in the crystal structure. The crystal structure shows the second, third and fourth zinc finger domains inserted deep into the major groove of the DNA where they make base-specific interactions. The DNA duplex is distorted in the vicinity of the first zinc finger, with a cytidine twisted and tilted out of the base stack to pack against finger 1 and the tip of finger 2. By contrast, the composite X-ray/NMR structures show that finger I continues to follow the major groove in the solution complexes. However, the orientation of the helix is non-canonical, and the fingertip and the N terminus of the helix project out of the major groove; as a consequence, the zinc finger side-chains that are commonly involved in base recognition make no contact with the DNA. We conclude that finger 1 helps to anchor WT1 to the DNA by amplifying the binding affinity although it does not contribute significantly to binding specificity. The structures provide molecular level insights into the potential consequences of mutations in zinc fingers 2 and 3 that are associated with Denys-Drash syndrome and nephritic syndrome. The mutations are of two types, and either destabilize the zinc finger structure or replace key base contact residues. (c) 2007 Elsevier Ltd. All rights reserved.