1EGE

STRUCTURE OF T255E, E376G MUTANT OF HUMAN MEDIUM CHAIN ACYL-COA DEHYDROGENASE


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.75 Å
  • R-Value Work: 0.221 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Crystal structures of the wild type and the Glu376Gly/Thr255Glu mutant of human medium-chain acyl-CoA dehydrogenase: influence of the location of the catalytic base on substrate specificity.

Lee, H.J.Wang, M.Paschke, R.Nandy, A.Ghisla, S.Kim, J.J.

(1996) Biochemistry 35: 12412-12420

  • DOI: 10.1021/bi9607867
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Crystal structures of the wild type human medium-chain acyl-CoA dehydrogenase (MCADH) and a double mutant in which its active center base-arrangement has been altered to that of long chain acyl-CoA dehydrogenase (LCADH), Glu376Gly/Thr255Glu, have bee ...

    Crystal structures of the wild type human medium-chain acyl-CoA dehydrogenase (MCADH) and a double mutant in which its active center base-arrangement has been altered to that of long chain acyl-CoA dehydrogenase (LCADH), Glu376Gly/Thr255Glu, have been determined by X-ray crystallography at 2.75 and 2.4 A resolution, respectively. The catalytic base responsible for the alpha-proton abstraction from the thioester substrate is Glu376 in MCADH, while that in LCADH is Glu255 (MCADH numbering), located over 100 residues away in its primary amino acid sequence. The structures of the mutant complexed with C8-, C12, and C14-CoA have also been determined. The human enzyme structure is essentially the same as that of the pig enzyme. The structure of the mutant is unchanged upon ligand binding except for the conformations of a few side chains in the active site cavity. The substrate with chain length longer than C12 binds to the enzyme in multiple conformations at its omega-end. Glu255 has two conformations, "active" and "resting" forms, with the latter apparently stabilized by forming a hydrogen bond with Glu99. Both the direction in which Glu255 approaches the C alpha atom of the substrate and the distance between the Glu255 carboxylate and the C alpha atom are different from those of Glu376; these factors are responsible for the intrinsic differences in the kinetic properties as well as the substrate specificity. Solvent accessible space at the "midsection" of the active site cavity, where the C alpha-C beta bond of the thioester substrate and the isoalloxazine ring of the FAD are located, is larger in the mutant than in the wild type enzyme, implying greater O2 accessibility in the mutant which might account for the higher oxygen reactivity.


    Organizational Affiliation

    Department of Biochemistry, Medical College of Wisconsin, Milwaukee 53226, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
MEDIUM CHAIN ACYL-COA DEHYDROGENASE
A, B, C, D
396Homo sapiensMutation(s): 0 
Gene Names: ACADM
EC: 1.3.8.7
Find proteins for P11310 (Homo sapiens)
Go to Gene View: ACADM
Go to UniProtKB:  P11310
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
FAD
Query on FAD

Download SDF File 
Download CCD File 
A, B, C, D
FLAVIN-ADENINE DINUCLEOTIDE
C27 H33 N9 O15 P2
VWWQXMAJTJZDQX-UYBVJOGSSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.75 Å
  • R-Value Work: 0.221 
  • Space Group: P 43 21 2
Unit Cell:
Length (Å)Angle (°)
a = 169.590α = 90.00
b = 169.590β = 90.00
c = 151.100γ = 90.00
Software Package:
Software NamePurpose
X-PLORmodel building
R-AXISdata reduction
X-PLORphasing
X-PLORrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1997-06-16
    Type: Initial release
  • Version 1.1: 2008-03-24
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance