Crystal structure of murine CsfF-77: Dimeric Association and implications for polyadenylation of mRNA precursors
Crystal structure of murine CsfF-77: Dimeric Association and implications for polyadenylation of mRNA precursors
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DOI：
10.1016/j.molcel.2007.01.034
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发表时间：
2007-03-23
期刊：
影响因子：
16
通讯作者：
Tong, Liang
中科院分区：
文献类型：
--
作者：
Bai, Yun;Auperin, Thierry C.;Tong, Liang
切割刺激因子（CstF）是mRNA前体的多聚腺苷酸化所必需的异源三聚体蛋白复合物。已知77 kDa亚基CstF-77介导与CstF的其他两个亚基以及与多聚腺苷酸化机制的其他组分的相互作用。我们在这里报告的晶体结构的HAT（半TPR）结构域的小鼠CstF-77，以及其C-末端亚结构域。结构和生物化学研究表明，HAT结构域由两个亚结构域，HAT-N和HAT-C结构域，其螺旋基序的方向截然不同。该结构揭示了高度伸长的二聚体，跨越165 A，具有由HAT-C结构域介导的二聚化。光散射研究，酵母双杂交测定，和分析ultracenthegation测量证实了这一selfassociation。二聚化模式和HAT-N和HAT-C结构域的相对排列是CstF-77所独有的。我们的数据支持CstF二聚化在pre-mRNA 3'末端加工中的作用。
Cleavage stimulation factor (CstF) is a heterotrimeric protein complex essential for polyadenylation of mRNA precursors. The 77 kDa subunit, CstF-77, is known to mediate interactions with the other two subunits of CstF as well as with other components of the polyadenylation machinery. We report here the crystal structure of the HAT (half a TPR) domain of murine CstF-77, as well as its C-terminal subdomain. Structural and biochemical studies show that the HAT domain consists of two subdomains, HAT-N and HAT-C domains, with drastically different orientations of their helical motifs. The structures reveal a highly elongated dimer, spanning 165 A, with the dimerization mediated by the HAT-C domain. Light-scattering studies, yeast two-hybrid assays, and analytical ultracentrifugation measurements confirm this selfassociation. The mode of dimerization and the relative arrangement of the HAT-N and HAT-C domains are unique to CstF-77. Our data support a role for CstF dimerization in pre-mRNA 3' end processing.