Cheng Zhihong, Liu Yuying, Wang Chernhoe, Parker Roy, Song Haiwei
Laboratory of Macromolecular Structure, Institute of Molecular and Cell Biology, 30 Medical Drive, Singapore 117609.
Protein Sci. 2004 Oct;13(10):2673-84. doi: 10.1110/ps.04856504. Epub 2004 Aug 31.
Ski8p is a WD-repeat protein with an essential role for the Ski complex assembly in an exosome-dependent 3'-to-5' mRNA decay. In addition, Ski8p is involved in meiotic recombination by interacting with Spo11p protein. We have determined the crystal structure of Ski8p from Saccharomyces cerevisiae at 2.2 A resolution. The structure reveals that Ski8p folds into a seven-bladed beta propeller. Mapping sequence conservation and hydrophobicities of amino acids on the molecular surface of Ski8p reveals a prominent site on the top surface of the beta propeller, which is most likely involved in mediating interactions of Ski8p with Ski3p and Spo11p. Mutagenesis combined with yeast two-hybrid and GST pull-down assays identified the top surface of the beta propeller as being required for Ski8p binding to Ski3p and Spo11p. The functional implications for Ski8p function in both mRNA decay and meiotic recombination are discussed.
Ski8p是一种WD重复蛋白,在依赖外泌体的3'至5'mRNA衰变中对Ski复合体的组装起着至关重要的作用。此外,Ski8p通过与Spo11p蛋白相互作用参与减数分裂重组。我们已经确定了酿酒酵母中Ski8p的晶体结构,分辨率为2.2埃。该结构表明,Ski8p折叠成一个七叶β螺旋桨。在Ski8p分子表面绘制氨基酸的序列保守性和疏水性,揭示了β螺旋桨顶表面的一个突出位点,该位点很可能参与介导Ski8p与Ski3p和Spo11p的相互作用。诱变结合酵母双杂交和GST下拉试验确定,β螺旋桨的顶表面是Ski8p与Ski3p和Spo11p结合所必需的。文中还讨论了Ski8p在mRNA衰变和减数分裂重组中的功能意义。