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|1y8n, resolution 2.60Å ()|
|Gene:||PDK3 (Homo sapiens), DLAT, DLTA (Homo sapiens)|
Crystal structure of the PDK3-L2 complex
The human pyruvate dehydrogenase complex (PDC) is regulated by reversible phosphorylation by four isoforms of pyruvate dehydrogenase kinase (PDK). PDKs phosphorylate serine residues in the dehydrogenase (E1p) component of PDC, but their amino-acid sequences are unrelated to eukaryotic Ser/Thr/Tyr protein kinases. PDK3 binds to the inner lipoyl domains (L2) from the 60-meric transacetylase (E2p) core of PDC, with concomitant stimulated kinase activity. Here, we present crystal structures of the PDK3-L2 complex with and without bound ADP or ATP. These structures disclose that the C-terminal tail from one subunit of PDK3 dimer constitutes an integral part of the lipoyl-binding pocket in the N-terminal domain of the opposing subunit. The two swapped C-terminal tails promote conformational changes in active-site clefts of both PDK3 subunits, resulting in largely disordered ATP lids in the ADP-bound form. Our structural and biochemical data suggest that L2 binding stimulates PDK3 activity by disrupting the ATP lid, which otherwise traps ADP, to remove product inhibition exerted by this nucleotide. We hypothesize that this allosteric mechanism accounts, in part, for E2p-augmented PDK3 activity.
Crystal structure of pyruvate dehydrogenase kinase 3 bound to lipoyl domain 2 of human pyruvate dehydrogenase complex., Kato M, Chuang JL, Tso SC, Wynn RM, Chuang DT, EMBO J. 2005 May 18;24(10):1763-74. Epub 2005 Apr 28. PMID:15861126
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
[ODP2_HUMAN] Note=Primary biliary cirrhosis is a chronic, progressive cholestatic liver disease characterized by the presence of antimitochondrial autoantibodies in patients' serum. It manifests with inflammatory obliteration of intra-hepatic bile duct, leading to liver cell damage and cirrhosis. Patients with primary biliary cirrhosis show autoantibodies against the E2 component of pyruvate dehydrogenase complex. Defects in DLAT are the cause of pyruvate dehydrogenase E2 deficiency (PDHE2 deficiency) [MIM:245348]; also known as lactic acidemia due to defect of E2 lipoyl transacetylase of the pyruvate dehydrogenase complex. Pyruvate dehydrogenase (PDH) deficiency is a major cause of primary lactic acidosis and neurological dysfunction in infancy and early childhood. In this form of PDH deficiency episodic dystonia is the major neurological manifestation, with other more common features of pyruvate dehydrogenase deficiency, such as hypotonia and ataxia, being less prominent.
[PDK3_HUMAN] Inhibits pyruvate dehydrogenase activity by phosphorylation of the E1 subunit PDHA1, and thereby regulates glucose metabolism and aerobic respiration. Can also phosphorylate PDHA2. Decreases glucose utilization and increases fat metabolism in response to prolonged fasting, and as adaptation to a high-fat diet. Plays a role in glucose homeostasis and in maintaining normal blood glucose levels in function of nutrient levels and under starvation. Plays a role in the generation of reactive oxygen species. [ODP2_HUMAN] The pyruvate dehydrogenase complex catalyzes the overall conversion of pyruvate to acetyl-CoA and CO(2), and thereby links the glycolytic pathway to the tricarboxylic cycle.
About this Structure
- Kato M, Chuang JL, Tso SC, Wynn RM, Chuang DT. Crystal structure of pyruvate dehydrogenase kinase 3 bound to lipoyl domain 2 of human pyruvate dehydrogenase complex. EMBO J. 2005 May 18;24(10):1763-74. Epub 2005 Apr 28. PMID:15861126
- ↑ Baker JC, Yan X, Peng T, Kasten S, Roche TE. Marked differences between two isoforms of human pyruvate dehydrogenase kinase. J Biol Chem. 2000 May 26;275(21):15773-81. PMID:10748134 doi:10.1074/jbc.M909488199
- ↑ Korotchkina LG, Patel MS. Site specificity of four pyruvate dehydrogenase kinase isoenzymes toward the three phosphorylation sites of human pyruvate dehydrogenase. J Biol Chem. 2001 Oct 5;276(40):37223-9. Epub 2001 Aug 2. PMID:11486000 doi:10.1074/jbc.M103069200
- ↑ Korotchkina LG, Sidhu S, Patel MS. Characterization of testis-specific isoenzyme of human pyruvate dehydrogenase. J Biol Chem. 2006 Apr 7;281(14):9688-96. Epub 2006 Jan 25. PMID:16436377 doi:10.1074/jbc.M511481200
- ↑ Lu CW, Lin SC, Chen KF, Lai YY, Tsai SJ. Induction of pyruvate dehydrogenase kinase-3 by hypoxia-inducible factor-1 promotes metabolic switch and drug resistance. J Biol Chem. 2008 Oct 17;283(42):28106-14. doi: 10.1074/jbc.M803508200. Epub 2008, Aug 21. PMID:18718909 doi:10.1074/jbc.M803508200
- ↑ Kluza J, Corazao-Rozas P, Touil Y, Jendoubi M, Maire C, Guerreschi P, Jonneaux A, Ballot C, Balayssac S, Valable S, Corroyer-Dulmont A, Bernaudin M, Malet-Martino M, de Lassalle EM, Maboudou P, Formstecher P, Polakowska R, Mortier L, Marchetti P. Inactivation of the HIF-1alpha/PDK3 signaling axis drives melanoma toward mitochondrial oxidative metabolism and potentiates the therapeutic activity of pro-oxidants. Cancer Res. 2012 Oct 1;72(19):5035-47. doi: 10.1158/0008-5472.CAN-12-0979. Epub, 2012 Aug 3. PMID:22865452 doi:10.1158/0008-5472.CAN-12-0979
- ↑ Kato M, Chuang JL, Tso SC, Wynn RM, Chuang DT. Crystal structure of pyruvate dehydrogenase kinase 3 bound to lipoyl domain 2 of human pyruvate dehydrogenase complex. EMBO J. 2005 May 18;24(10):1763-74. Epub 2005 Apr 28. PMID:15861126
- ↑ Kato M, Li J, Chuang JL, Chuang DT. Distinct structural mechanisms for inhibition of pyruvate dehydrogenase kinase isoforms by AZD7545, dichloroacetate, and radicicol. Structure. 2007 Aug;15(8):992-1004. Epub 2007 Aug 2. PMID:17683942 doi:10.1016/j.str.2007.07.001