Regulatory roles of the N-terminal domain based on crystal structures of human pyruvate dehydrogenase kinase 2 containing physiological and synthetic ligands
Regulatory roles of the N-terminal domain based on crystal structures of human pyruvate dehydrogenase kinase 2 containing physiological and synthetic ligands
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DOI：
10.1021/bi051402s
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发表时间：
2006-01-17
期刊：
影响因子：
2.9
通讯作者：
Brown, DG
中科院分区：
文献类型：
--
作者：
Knoechel, TR;Tucker, AD;Brown, DG
丙酮酸脱氢酶激酶（PDHK）调节丙酮酸脱氢酶多酶复合物的活性。PDHK抑制为糖尿病和心血管疾病的治疗干预提供了途径。我们报告了人PDHK同工酶2与生理和合成配体复合的晶体结构。所公开的几种PDHK2结构具有跨越PDHK2二聚体的N-末端调节（R）结构域之间的大的谷区的C-末端横臂。含有结合ATP和ADP的结构表明活性位点lid（残基316 - 321）构象的变化，其在C-末端催化结构域的活性位点处包围核苷酸β和γ磷酸。我们已经确定了三个新的配体结合位点位于PDHK2的R结构域。二氯乙酸（DCA）结合在R结构域中心的丙酮酸结合位点，其与ADP一起诱导活性位点的显著变化。Nov3r和AZ12抑制剂在位于R结构域一端的硫辛酰胺结合位点处结合。Pfz3（一种变构抑制剂）结合在R结构域另一端的延伸位点。我们的结论是，N-末端结构域的PDHK具有关键的调节功能，并提出不同的抑制剂类的作用离散的机制。我们描述的结构提供了可用于PDHK抑制剂的基于结构的设计的见解。
Pyruvate dehydrogenase kinase (PDHK) regulates the activity of the pyruvate dehydrogenase multienzyme complex. PDHK inhibition provides a route for therapeutic intervention in diabetes and cardiovascular disorders. We report crystal structures of human PDHK isozyme 2 complexed with physiological and synthetic ligands. Several of the PDHK2 structures disclosed have C-terminal cross arms that span a large trough region between the N-terminal regulatory (R) domains of the PDHK2 dimers. The structures containing bound ATP and ADP demonstrate variation in the conformation of the active site lid, residues 316-321, which enclose the nucleotide beta and gamma phosphates at the active site in the C-terminal catalytic domain. We have identified three novel ligand binding sites located in the R domain of PDHK2. Dichloroacetate (DCA) binds at the pyruvate binding site in the center of the R domain, which together with ADP, induces significant changes at the active site. Nov3r and AZ12 inhibitors bind at the lipoamide binding site that is located at one end of the R domain. Pfz3 (an allosteric inhibitor) binds in an extended site at the other end of the R domain. We conclude that the N-terminal domain of PDHK has a key regulatory function and propose that the different inhibitor classes act by discrete mechanisms. The structures we describe provide insights that can be used for structure-based design of PDHK inhibitors.