Protein and RNA dynamics play key roles in determining the specific recognition of GU-rich polyadenylation regulatory elements by human Cstf-64 protein
Protein and RNA dynamics play key roles in determining the specific recognition of GU-rich polyadenylation regulatory elements by human Cstf-64 protein
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DOI：
10.1016/j.jmb.2005.01.046
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发表时间：
2005-04-08
影响因子：
5.6
通讯作者：
Varani, G
中科院分区：
文献类型：
--
作者：
Deka, P;Rajan, PK;Varani, G
裂解刺激因子（CstF-64）的64 kDa亚基的n端结构域识别真核mrna的3 '-非翻译区中富含gu的元件。这种相互作用对于mRNA 3 '端加工和转录终止至关重要，其强度影响不同聚腺苷化位点的利用效率。CstF-64的RNA结合n端结构域的结构显示了CstF-64的n端RNA识别基序如何识别富含gu的RNA。然而，该蛋白如何能够选择性地与富含G和U残基的rna结合，而不考虑其详细的序列组成，同时有效地区分非gu - rna，这仍然是一个困惑。我们通过核磁共振研究了CstF-64 RNA结合域的动力学，包括自由和结合两个富含gu的RNA序列，它们代表多腺苷化调节元件。虽然自由蛋白显示出典型的折叠良好的蛋白质结构域的运动特性，并且是均匀刚性的，但一旦富含gu的rna结合到蛋白质- rna界面上，它就会在微到毫秒的时间尺度上获得显著的移动性。这些运动特征，我们提出，是内在的功能要求，以结合所有富谷氨酸序列，但不歧视非富谷氨酸rna。这种行为可能是一些rna结合蛋白能够与序列类结合的一般机制，而不是明确定义的序列或共识。(c) 2005 Elsevier Ltd版权所有。
The N-terminal domain of the 64 kDa subunit of the cleavage stimulation factor (CstF-64) recognizes GU-rich elements within the 3 '-untranslated region of eukaryotic mRNAs. This interaction is essential for mRNA 3 ' end processing and transcription termination, and its strength affects the efficiency of utilization of different polyadenylation sites. The structure of the RNA-binding N-terminal domain of CstF-64 showed how the N-terminal RNA recognition motif of CstF-64 recognizes GU-rich RNAs. However, it is still perplexing how this protein can bind selectively to RNAs that are rich in G and U residues regardless of their detailed sequence composition, yet discriminate effectively against non-GU-RNAs. We investigated by NMR the dynamics of the CstF-64 RNA-binding domain, both free and bound to two GU-rich RNA sequences that represent polyadenylation regulatory elements. While the free protein displays the motional properties typical of a well-folded protein domain and is uniformly rigid, the protein-RNA interface acquires significant mobility on the micro- to millisecond time-scale once GU-rich RNAs binds to it. These motional features, we propose, are intrinsic to the functional requirement to bind all GU-rich sequences and yet to discriminate against non-GU-rich RNAs. This behavior may be a general mechanism by which some RNA-binding proteins are able to bind to classes of sequences, as opposed to a well-defined sequence or consensus. (c) 2005 Elsevier Ltd. All rights reserved.