1QR6

HUMAN MITOCHONDRIAL NAD(P)-DEPENDENT MALIC ENZYME


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.1 Å
  • R-Value Free: 0.287 
  • R-Value Work: 0.228 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Crystal structure of human mitochondrial NAD(P)(+)-dependent malic enzyme: a new class of oxidative decarboxylases.

Xu, Y.Bhargava, G.Wu, H.Loeber, G.Tong, L.

(1999) Structure 7: 877-889


  • PubMed Abstract: 
  • Background: Malic enzymes catalyze the oxidative decarboxylation of malate to pyruvate and CO(2) with the concomitant reduction of NAD(P)(+) to NAD(P)H. They are widely distributed in nature and have important biological functions. Human mitochondria ...

    Background: Malic enzymes catalyze the oxidative decarboxylation of malate to pyruvate and CO(2) with the concomitant reduction of NAD(P)(+) to NAD(P)H. They are widely distributed in nature and have important biological functions. Human mitochondrial NAD(P)(+)-dependent malic enzyme (mNAD-ME) may have a crucial role in the metabolism of glutamine for energy production in rapidly dividing cells and tumors. Moreover, this isoform is unique among malic enzymes in that it is a cooperative enzyme, and its activity is controlled allosterically. Results: The crystal structure of human mNAD-ME has been determined at 2.5 Å resolution by the selenomethionyl multiwavelength anomalous diffraction method and refined to 2.1 Å resolution. The structure of the monomer can be divided into four domains; the active site of the enzyme is located in a deep cleft at the interface between three of the domains. Three acidic residues (Glu255, Asp256 and Asp279) were identified as ligands for the divalent cation that is required for catalysis by malic enzymes. Conclusions: The structure reveals that malic enzymes belong to a new class of oxidative decarboxylases. The tetramer of the enzyme appears to be a dimer of dimers. The active site of each monomer is located far from the tetramer interface. The structure also shows the binding of a second NAD(+) molecule in a pocket 35 Å away from the active site. The natural ligand for this second binding site may be ATP, an allosteric inhibitor of the enzyme.


    Organizational Affiliation

    Department of Biological Sciences Columbia University New York, NY 10027, USA




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
MALIC ENZYME 2
A, B
584Homo sapiensMutation(s): 0 
Gene Names: ME2
EC: 1.1.1.38
Find proteins for P23368 (Homo sapiens)
Go to Gene View: ME2
Go to UniProtKB:  P23368
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
NAD
Query on NAD

Download SDF File 
Download CCD File 
A, B
NICOTINAMIDE-ADENINE-DINUCLEOTIDE
C21 H27 N7 O14 P2
BAWFJGJZGIEFAR-NNYOXOHSSA-N
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
MSE
Query on MSE
A, B
L-PEPTIDE LINKINGC5 H11 N O2 SeMET
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.1 Å
  • R-Value Free: 0.287 
  • R-Value Work: 0.228 
  • Space Group: B 1 1 2
Unit Cell:
Length (Å)Angle (°)
a = 204.400α = 90.00
b = 107.000β = 90.00
c = 59.200γ = 101.90
Software Package:
Software NamePurpose
SCALEPACKdata scaling
X-PLORrefinement
DENZOdata reduction
MADSYSphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1999-07-05
    Type: Initial release
  • Version 1.1: 2008-04-27
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Derived calculations, Version format compliance