Regulatory Roles of the N-Terminal Domain Based on Crystal Structures of Human Pyruvate Dehydrogenase Kinase 2 Containing Physiological and Synthetic Ligands.Knoechel, T.R., Tucker, A.D., Robinson, C.M., Phillips, C., Taylor, W., Bungay, P.J., Kasten, S.A., Roche, T.E., Brown, D.G.
(2006) Biochemistry 45: 402
- PubMed: 16401071
- DOI: 10.1021/bi051402s
- Primary Citation of Related Structures:
2BTZ, 2BU8, 2BU7, 2BU6, 2BU5, 2BU2
- PubMed Abstract:
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 P ...
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.
PGRD Sandwich, Pfizer Ltd, Sandwich, Kent CT139NJ, United Kingdom.