The RGG domain of Npl3p recruits Sky1p through docking interactions
The RGG domain of Npl3p recruits Sky1p through docking interactions
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DOI：
10.1016/j.jmb.2006.12.031
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发表时间：
2007-03-16
影响因子：
5.6
通讯作者：
Ghosh, Gourisankar
中科院分区：
文献类型：
--
作者：
Lukasiewicz, Randall;Nolen, Bradley;Ghosh, Gourisankar
酵母中的SR蛋白激酶Sky 1 p在位于其C末端的单个丝氨酸残基处磷酸化酵母SR样蛋白Npl 3 p。我们在这里报告的X-射线晶体结构的Sky 1 p绑定到底物肽和ADP。令人惊讶的是，Npl 3 p衍生的底物肽占据了距离激酶活性位点20 A的凹槽。体外研究支持该沟的基底对接作用。突变和结合研究表明，位于Npl 3 p的RGG结构域内的多个简并短肽基序充当底物对接基序。然而，单个对接基序足以使其与激酶稳定相互作用。对接基序的甲基化消除了Npl 3 p的激酶结合和磷酸化。值得注意的是，去除激酶中的对接槽或底物的对接基序不会以任何显著的方式降低磷酸化反应的总催化效率。我们认为，对接之间的相互作用Sky 1 p和Npl 3 p是必不可少的底物招聘和结合特异性。(c)2007年由Elsevier Ltd.出版
The SR protein kinase in yeast, Sky1p, phosphorylates yeast SR-like protein, Npl3p, at a single serine residue located at its C terminus. We report here the X-ray crystal structure of Sky1p bound to a substrate peptide and ADP. Surprisingly, an Npl3p-derived substrate peptide occupies a groove 20 A away from the kinase active site. In vitro studies support the substrate-docking role of this groove. Mutagenesis and binding studies reveal that multiple degenerate short peptide motifs located within the RGG domain of Npl3p serve as the substrate docking motifs. However, a single docking motif is sufficient for its stable interaction with the kinase. Methylation of the docking motifs abolishes kinase binding and phosphorylation of Npl3p. Remarkably, removal of the docking groove in the kinase or the docking motifs of the substrate does not reduce the overall catalytic efficiency of the phosphorylation reaction in any significant manner. We suggest that docking interaction between Sky1p and Npl3p is essential for substrate recruitment and binding specificity. (c) 2007 Published by Elsevier Ltd.