The structure of the C4C4 RING finger of human NOT4 reveals features distinct from those of C3HC4 RING fingers
The structure of the C4C4 RING finger of human NOT4 reveals features distinct from those of C3HC4 RING fingers
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DOI：
10.1074/jbc.m009298200
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发表时间：
2001-03-30
影响因子：
4.8
通讯作者：
Boelens, R
中科院分区：
文献类型：
--
作者：
Hanzawa, H;de Ruwe, MJ;Boelens, R
NOT4蛋白是CCR4 - NOT复合物的一个组分，该复合物是RNA聚合酶II转录的全局调节因子。人NOT4（hNOT4）包含一个C4C4型的环指结构域。我们表达并纯化了包含环指结构域的hNOT4的N端区域（残基1 - 78），并通过异核核磁共振确定了其溶液结构。使用镉 - 113取代的hNOT4环指进行的MMR实验表明，两个金属离子通过半胱氨酸残基以交叉支撑的方式结合。hNOT4环指的三维结构经过精修，主链原子的均方根偏差值为0.58 ± 0.13埃，重原子为1.08 ± 0.12埃。hNOT4环指由一个α - 螺旋和三个由锌配位稳定的长环组成。hNOT4环指的整体折叠与C3HC4环指相似。两个锌螯合环和α - 螺旋的相对取向是非常保守的。然而，对于其他区域，二级结构元件是不同的。
The NOT4 protein is a component of the CCR4.NOT complex, a global regulator of RNA polymerase II transcription. Human NOT4 (hNOT4) contains a RING finger motif of the C4C4 type. We expressed and purified the N-terminal region of hNOT4 (residues 1-78) encompassing the RING finger motif and determined the solution structure by heteronuclear NMR. MMR experiments using a Cd-113-substituted hNOT4 RING finger showed that two metal ions are bound through cysteine residues in a cross-brace manner. The three-dimensional structure of the hNOT4 RING finger was refined with root mean square deviation values of 0.58 +/- 0.13 Angstrom for the backbone atoms and 1.08 +/- 0.12 Angstrom for heavy atoms. The hNOT4 RING finger consists of an cw-helix and three long loops that are stabilized by zinc coordination. The overall folding of the hNOT4 RING finger is similar to that of the C3HC4 RING fingers. The relative orientation of the two zinc-chelating loops and the alpha -helix is well conserved. However, for the other regions, the secondary structural elements are distinct.