1X7Z

Crystal structure of the human mitochondrial branched-chain alpha-ketoacid dehydrogenase


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.72 Å
  • R-Value Free: 0.189 
  • R-Value Work: 0.153 
  • R-Value Observed: 0.154 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Molecular mechanism for regulation of the human mitochondrial branched-chain alpha-ketoacid dehydrogenase complex by phosphorylation

Wynn, R.M.Kato, M.Machius, M.Chuang, J.L.Li, J.Tomchick, D.R.Chuang, D.T.

(2004) Structure 12: 2185-2196

  • DOI: 10.1016/j.str.2004.09.013
  • Primary Citation of Related Structures:  
    1U5B, 1X80, 1X7W, 1X7Z, 1X7Y, 1X7X

  • PubMed Abstract: 
  • The human mitochondrial branched-chain alpha-ketoacid dehydrogenase complex (BCKDC) is a 4 MDa macromolecular machine comprising three catalytic components (E1b, E2b, and E3), a kinase, and a phosphatase. The BCKDC overall activity is tightly regulat ...

    The human mitochondrial branched-chain alpha-ketoacid dehydrogenase complex (BCKDC) is a 4 MDa macromolecular machine comprising three catalytic components (E1b, E2b, and E3), a kinase, and a phosphatase. The BCKDC overall activity is tightly regulated by phosphorylation in response to hormonal and dietary stimuli. We report that phosphorylation of Ser292-alpha in the E1b active site channel results in an order-to-disorder transition of the conserved phosphorylation loop carrying the phosphoryl serine. The conformational change is triggered by steric clashes of the phosphoryl group with invariant His291-alpha that serves as an indispensable anchor for the phosphorylation loop through bound thiamin diphosphate. Phosphorylation of Ser292-alpha does not severely impede the E1b-dependent decarboxylation of alpha-ketoacids. However, the disordered loop conformation prevents phosphorylated E1b from binding the E2b lipoyl-bearing domain, which effectively shuts off the E1b-catalyzed reductive acylation reaction and therefore completely inactivates BCKDC. This mechanism provides a paradigm for regulation of mitochondrial alpha-ketoacid dehydrogenase complexes by phosphorylation.


    Related Citations: 
    • Crosstalk between Thiamin Diphosphate Binding and Phosphorylation Loop Conformation in Human Branched-Chain A-Ketoacid Decarboxylase/Dehydrogenase
      Li, J., Wynn, R.M., Machius, M., Chuang, J.L., Karthikeyan, S., Tomchick, D.R., Chuang, D.T.
      (2004) J Biol Chem 279: 32968
    • Roles of His291-Alpha and His146-Beta in the Reductive Acylation Reaction Catalyzed by Human Branched-Chain Alpha-Ketoacid Dehydrogenase: Refined Phosphorylation Loop Structure in the Active Site
      Wynn, R.M., Machius, M., Chuang, J.L., Li, J., Tomchick, D.R., Chuang, D.T.
      (2003) J Biol Chem 278: 43402

    Organizational Affiliation

    Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
2-oxoisovalerate dehydrogenase alpha subunitA400Homo sapiensMutation(s): 1 
Gene Names: BCKDHA
EC: 1.2.4.4
Find proteins for P12694 (Homo sapiens)
Explore P12694 
Go to UniProtKB:  P12694
NIH Common Fund Data Resources
PHAROS  P12694
Protein Feature View
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
2-oxoisovalerate dehydrogenase beta subunitB342Homo sapiensMutation(s): 0 
Gene Names: BCKDHB
EC: 1.2.4.4
Find proteins for P21953 (Homo sapiens)
Explore P21953 
Go to UniProtKB:  P21953
NIH Common Fund Data Resources
PHAROS  P21953
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 5 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
TDP
Query on TDP

Download CCD File 
A
THIAMIN DIPHOSPHATE
C12 H18 N4 O7 P2 S
AYEKOFBPNLCAJY-UHFFFAOYSA-N
 Ligand Interaction
GOL
Query on GOL

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B
GLYCEROL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
 Ligand Interaction
MN
Query on MN

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A
MANGANESE (II) ION
Mn
WAEMQWOKJMHJLA-UHFFFAOYSA-N
 Ligand Interaction
K
Query on K

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A, B
POTASSIUM ION
K
NPYPAHLBTDXSSS-UHFFFAOYSA-N
 Ligand Interaction
CL
Query on CL

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A
CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
TDPKd:  40300   nM  Binding MOAD
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.72 Å
  • R-Value Free: 0.189 
  • R-Value Work: 0.153 
  • R-Value Observed: 0.154 
  • Space Group: P 31 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 145.31α = 90
b = 145.31β = 90
c = 69.322γ = 120
Software Package:
Software NamePurpose
HKL-2000data collection
HKL-2000data reduction
AMoREphasing
REFMACrefinement
HKL-2000data scaling

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2004-11-23
    Type: Initial release
  • Version 1.1: 2008-04-30
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Derived calculations, Version format compliance