Solution structure of the second RNA recognition motif (RRM) domain of murine T cell intracellular antigen-1 (TIA-1) and its RNA recognition mode
Solution structure of the second RNA recognition motif (RRM) domain of murine T cell intracellular antigen-1 (TIA-1) and its RNA recognition mode
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DOI：
10.1021/bi7024723
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发表时间：
2008-06-17
期刊：
影响因子：
2.9
通讯作者：
Yokoyama, Shigeyuki
中科院分区：
文献类型：
--
作者：
Kuwasako, Kanako;Takahashi, Mari;Yokoyama, Shigeyuki
T细胞胞内抗原-1（TIA-1）是一种细胞凋亡促进因子，可作为Fas前体mRNA的剪接调节因子发挥作用。TIA-1具有三个RNA识别基序（RRM）和一个富含谷氨酰胺的结构域。第二个RRM（RRM 2）是必要的，足以紧密，序列特异性结合的尿苷丰富的序列周围的5'剪接位点。在本研究中，我们解决了小鼠TIA-1 RRM 2的溶液结构的异核核磁共振光谱。TIA-1 RRM 2采用RRM折叠（β α β α β），并在β 2和β 3之间拥有额外的β链，其与β 2的C末端部分形成额外的β折叠。我们把这种结构称为β 2-β 2'β环。有趣的是，这种特征性的β环结构在许多RRM中是保守的，包括U2 AF 65 RRM 2和性致死RRM 1和RRM 2，它们也与富含尿苷的RNA结合。此外，我们在β 2-β 2'β环中鉴定了一个新的序列基序，即DxxT基序。结合到尿苷五聚体RNA后的主链和侧链的化学位移扰动分析显示，大多数β-折叠表面，包括β 2-β 2'β-环，参与RNA结合。化学位移扰动的研究揭示了TIA-1和U2 AF 65 RRM之间的RNA识别模式的相似性。
T cell intracellular antigen-1 (TIA-1), an apoptosis promoting factor, functions as a splicing regulator for the Fas pre-mRNA. TIA-1 possesses three RNA recognition motifs (RRMs) and a glutamine-rich domain. The second RRM (RRM2) is necessary and sufficient for tight, sequence-specific binding to the uridine-rich sequences buried around the 5' splice sites. In the present study, we solved the solution structure of the murine TIA-1 RRM2 by heteronuclear-nuclear magnetic resonance spectroscopy. The TIA-1 RRM2 adopts the RRM fold (beta alpha beta beta alpha beta) and possesses an extra beta-strand between beta 2 and beta 3, which forms an additional beta-sheet with the C-terminal part of beta 2. We refer to this structure as the beta 2-beta 2' beta-loop. Interestingly, this characteristic beta-loop structure is conserved among a number of RRMs, including the U2AF65 RRM2 and the Sex-lethal RRM1 and RRM2, which also bind to uridine-rich RNAs. Furthermore, we identified a new sequence motif in the beta 2-beta 2' beta-loop, the DxxT motif. Chemical shift perturbation analyses of both the main and side chains upon binding to the uridine pentamer RNA revealed that most of the beta-sheet surface, including the beta 2-beta 2' beta-loop, is involved in the RNA binding. An investigation of the chemical shift perturbation revealed similarity in the RNA recognition modes between the TIA-1 and U2AF65 RRMs.