High resolution crystal structure of the human PDK1 catalytic domain defines the regulatory phosphopeptide docking site
High resolution crystal structure of the human PDK1 catalytic domain defines the regulatory phosphopeptide docking site
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DOI：
10.1093/emboj/cdf437
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发表时间：
2002-08-15
期刊：
影响因子：
11.4
通讯作者：
van Aalten, DMF
中科院分区：
文献类型：
--
作者：
Biondi, RM;Komander, D;van Aalten, DMF
3-磷酸肌醇依赖性蛋白激酶-1（PDK 1）通过激活AGC激酶如PKB/Akt和S6 K在调节信号传导途径中起关键作用。在这里，我们描述了与ATP复合的PDK 1激酶结构域的2.0埃晶体结构。该结构定义了称为“PIF口袋”的疏水口袋，其在介导某些底物如S6 K1的相互作用和磷酸化中起关键作用。S6 K1在其C-末端PIF-口袋相互作用基序处的磷酸化促进S6 K1与PDK 1的结合。在PDK 1结构中，这个口袋被与另一个PDK 1分子的晶体接触占据。有趣的是，在PDK 1的PIF口袋附近，有一个有序的硫酸根离子，与周围的四个侧链紧密相互作用。这些残基的作用进行了研究，通过结合定点诱变和动力学研究，其结果证实，PDK 1的这一区域代表磷酸依赖性对接位点。我们讨论的可能性，一个类似的磷酸盐结合调节基序可能参与其他AGC激酶的激活。此外，PDK 1的结构为设计特异性PDK 1抑制剂提供了支架。
3-phosphoinositide dependent protein kinase-1 (PDK1) plays a key role in regulating signalling pathways by activating AGC kinases such as PKB/Akt and S6K. Here we describe the 2.0 Angstrom crystal structure of the PDK1 kinase domain in complex with ATP. The structure defines the hydrophobic pocket termed the 'PIF-pocket', which plays a key role in mediating the interaction and phosphorylation of certain substrates such as S6K1. Phosphorylation of S6K1 at its C-terminal PIF-pocket-interacting motif promotes the binding of S6K1 with PDK1. In the PDK1 structure, this pocket is occupied by a crystallographic contact with another molecule of PDK1. Interestingly, close to the PIF-pocket in PDK1, there is an ordered sulfate ion, interacting tightly with four surrounding side chains. The roles of these residues were investigated through a combination of site-directed mutagenesis and kinetic studies, the results of which confirm that this region of PDK1 represents a phosphate-dependent docking site. We discuss the possibility that an analogous phosphate-binding regulatory motif may participate in the activation of other AGC kinases. Furthermore, the structure of PDK1 provides a scaffold for the design of specific PDK1 inhibitors.