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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- 作者：Thorsten R. Knoechel ; Alec D. Tucker ; Colin M. Robinson ; Chris Phillips ; Wendy Taylor ; Peter J. Bungay ; Shane A. Kasten ; Thomas E. Roche ; and David G. Brown
- 刊名：Biochemistry
- 出版年：2006
- 出版时间：January 17, 2006
- 年：2006
- 卷：45
- 期：2
- 页码：402 - 415
- 全文大小：1156K
- 年卷期：v.45,no.2(January 17, 2006)
- ISSN：1520-4995
文摘
Pyruvate dehydrogenase kinase (PDHK) regulates the activity of the pyruvate dehydrogenasemultienzyme complex. PDHK inhibition provides a route for therapeutic intervention in diabetes andcardiovascular disorders. We report crystal structures of human PDHK isozyme 2 complexed withphysiological and synthetic ligands. Several of the PDHK2 structures disclosed have C-terminal crossarms 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 activesite lid, residues 316-321, which enclose the nucleotide 
and 
phosphates at the active site in theC-terminal catalytic domain. We have identified three novel ligand binding sites located in the R domainof 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 bindat 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 ofPDHK has a key regulatory function and propose that the different inhibitor classes act by discretemechanisms. The structures we describe provide insights that can be used for structure-based design ofPDHK inhibitors.
and phosphates at the active site in theC-terminal catalytic domain. We have identified three novel ligand binding sites located in the R domainof 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 bindat 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 ofPDHK has a key regulatory function and propose that the different inhibitor classes act by discretemechanisms. The structures we describe provide insights that can be used for structure-based design ofPDHK inhibitors.