1UMB

branched-chain 2-oxo acid dehydrogenase (E1) from Thermus thermophilus HB8 in holo-form


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.1 Å
  • R-Value Free: 0.194 
  • R-Value Work: 0.169 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Ligand-induced Conformational Changes and a Reaction Intermediate in Branched-chain 2-Oxo Acid Dehydrogenase (E1) from Thermus thermophilus HB8, as Revealed by X-ray Crystallography

Nakai, T.Nakagawa, N.Maoka, N.Masui, R.Kuramitsu, S.Kamiya, N.

(2004) J.Mol.Biol. 337: 1011-1033

  • DOI: 10.1016/j.jmb.2004.02.011
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • The alpha(2)beta(2) tetrameric E1 component of the branched-chain 2-oxo acid (BCOA) dehydrogenase multienzyme complex is a thiamin diphosphate (ThDP)-dependent enzyme. E1 catalyzes the decarboxylation of a BCOA concomitant with the formation of the a ...

    The alpha(2)beta(2) tetrameric E1 component of the branched-chain 2-oxo acid (BCOA) dehydrogenase multienzyme complex is a thiamin diphosphate (ThDP)-dependent enzyme. E1 catalyzes the decarboxylation of a BCOA concomitant with the formation of the alpha-carbanion/enamine intermediate, 2-(1-hydroxyalkyl)-ThDP, followed by transfer of the 1-hydroxyalkyl group to the distal sulfur atom on the lipoamide of the E2 component. In order to elucidate the catalytic mechanism of E1, the alpha- and beta-subunits of E1 from Thermus thermophilus HB8 have been co-expressed in Escherichia coli, purified and crystallized as a stable complex, and the following crystal structures have been analyzed: the apoenzyme (E1(apo)), the holoenzyme (E1(holo)), E1(holo) in complex with the substrate analogue 4-methylpentanoate (MPA) as an ES complex model, and E1(holo) in complex with 4-methyl-2-oxopentanoate (MOPA) as the alpha-carbanion/enamine intermediate (E1(ceim)). Binding of cofactors to E1(apo) induces a disorder-order transition in two loops adjacent to the active site. Furthermore, upon binding of MPA to E1(holo), the loop comprised of Gly121beta-Gln131beta moves close to the active site and interacts with MPA. The carboxylate group of MPA is recognized mainly by Tyr86beta and N4' of ThDP. The hydrophobic moiety of MPA is recognized by Phe66alpha, Tyr95alpha, Met128alpha and His131alpha. As an intermediate, MOPA is decarboxylated and covalently linked to ThDP, and the conformation of the protein loop is almost the same as in the substrate-free (holoenzyme) form. These results suggest that E1 undergoes an open-closed conformational change upon formation of the ES complex with a BCOA, and the mobile region participates in the recognition of the carboxylate group of the BCOA. ES complex models of E1(holo).MOPA and of E1(ceim).lipoamide built from the above structures suggest that His273alpha and His129beta' are potential proton donors to the carbonyl group of a BCOA and to the proximal sulfur atom on the lipoamide, respectively.


    Organizational Affiliation

    RIKEN Harima Institute/SPring-8, 1-1-1 Kouto, Mikazuki, Sayo-gun, Hyogo 679-5148, Japan. nakaix@spring8.or.jp




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
2-oxo acid dehydrogenase alpha subunit
A, C
367Thermus thermophilus (strain HB8 / ATCC 27634 / DSM 579)Mutation(s): 0 
EC: 1.2.4.4
Find proteins for Q5SLR4 (Thermus thermophilus (strain HB8 / ATCC 27634 / DSM 579))
Go to UniProtKB:  Q5SLR4
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
2-oxo acid dehydrogenase beta subunit
B, D
324Thermus thermophilus (strain HB8 / ATCC 27634 / DSM 579)Mutation(s): 0 
EC: 1.2.4.4
Find proteins for Q5SLR3 (Thermus thermophilus (strain HB8 / ATCC 27634 / DSM 579))
Go to UniProtKB:  Q5SLR3
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
TDP
Query on TDP

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

Download SDF File 
Download CCD File 
A, C
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.1 Å
  • R-Value Free: 0.194 
  • R-Value Work: 0.169 
  • Space Group: C 2 2 21
Unit Cell:
Length (Å)Angle (°)
a = 127.629α = 90.00
b = 246.180β = 90.00
c = 137.052γ = 90.00
Software Package:
Software NamePurpose
AMoREphasing
SCALEPACKdata scaling
HKL-2000data reduction
CNSrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2004-03-30
    Type: Initial release
  • Version 1.1: 2008-04-27
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance