A disorder-to-order transition coupled to DNA binding in the essential zinc-finger DNA-binding domain of yeast ADR1.
A disorder-to-order transition coupled to DNA binding in the essential zinc-finger DNA-binding domain of yeast ADR1.
复制标题
酵母 ADR1 必需锌指 DNA 结合域中与 DNA 结合耦合的无序到有序转变。
DOI：
10.1006/jmbi.1998.1811
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发表时间：
1998
影响因子：
5.6
通讯作者：
Klevit,RE
中科院分区：
文献类型：
--
作者：
Hyre,DE;Klevit,RE
利用核磁共振技术研究了酵母转录因子ADR 1的最小锌指DNA结合结构域（ADR 1-DBD）的自由态和DNA结合态的运动动力学和溶剂交换行为。测量的参数包括1H-15 N杂原子NOE、15 N和1H T1弛豫速率、15 N T2弛豫速率和溶剂交换速率。自旋弛豫参数，光谱密度图，和溶剂交换行为表明，除了N和C末端，三个不同的区域的自由ADR 1-DBD表现出不同的运动在多个时间尺度上。N-末端近端或附件区域似乎是非结构化的和高度灵活的：它在皮秒时间尺度上表现出大幅度的运动，很少或没有保护溶剂交换和随机线圈质子化学位移。两个锌指翻转各向异性折叠域，与翻滚的个别手指只有部分相互关联，并适度保护溶剂交换，除了附近的手指的尖端和连接它们的接头。游离ADR 1-DBD在近端区域、手指1的尖端和整个手指2中表现出P97周围的交换增宽。结合后，大部分的近端区域和两个锌指翻转作为一个单一的域，并表现出显着减少皮秒时间尺度的运动。该区域变得更受保护免于溶剂交换。建议近端区域的结合部分暴露在DNA的表面上。交换加宽保持在P97附近，但对于与DNA直接接触的残基和接头中的残基也变得明显。我们的结论是，该地区的ADR 1-DBD高亲和力结合必不可少的经历了无序到有序的过渡后，结合到其同源DNA，并与锌指，形成一个有凝聚力的分子复合物的核酸。
The motional dynamics and solvent-exchange behavior of free and DNA-bound forms of the minimal zinc-finger DNA-binding domain of the yeast transcription factor ADR1 (ADR1-DBD) are investigated using NMR. The parameters measured include the1H-15N heteronuclear NOE,15N and1H T1relaxation rates,15N T2relaxation rates, and solvent-exchange rates. The spin relaxation parameters, spectral density maps, and solvent-exchange behavior show that, exclusive of the N and C termini, three distinct regions of free ADR1-DBD exhibit different motions on multiple timescales. The N-terminal proximal, or accessory, region appears to be unstructured and highly flexible: it exhibits large amplitude motions on a picosecond timescale, little or no protection from solvent exchange, and random-coil proton chemical shifts. The two zinc fingers tumble anisotropically as folded domains, with the tumbling of the individual fingers being only partly correlated to each other, and are modestly protected from solvent exchange except near the tips of the fingers and in the linker joining them. Free ADR1-DBD exhibits exchange broadening around P97 in the proximal region, at the tip of finger 1, and throughout finger 2. Upon binding, most of the proximal region and both zinc fingers tumble as a single domain and exhibit significantly reduced picosecond timescale motions. This region becomes more protected from solvent exchange. The bound portion of the proximal region is proposed to lie exposed on the surface of the DNA. Exchange broadening remains around P97 but also becomes evident for residues in direct contact with the DNA and in the linker. We conclude that the region of ADR1-DBD essential for high-affinity binding undergoes a disorder-to-order transition upon binding to its cognate DNA and, together with the zinc fingers, forms a cohesive molecular complex with the nucleic acid.