1NI6

Comparisions of the Heme-Free and-Bound Crystal Structures of Human Heme Oxygenase-1


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.1 Å
  • R-Value Free: 0.267 
  • R-Value Work: 0.217 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Comparison of the heme-free and -bound crystal structures of human heme oxygenase-1

Lad, L.Schuller, D.J.Shimizu, H.Friedman, J.Li, H.Ortiz de Montellano, P.R.Poulos, T.L.

(2003) J.Biol.Chem. 278: 7834-7843

  • DOI: 10.1074/jbc.M211450200
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Heme oxygenase (HO) catalyzes the degradation of heme to biliverdin. The crystal structure of human HO-1 in complex with heme reveals a novel helical structure with conserved glycines in the distal helix, providing flexibility to accommodate substrat ...

    Heme oxygenase (HO) catalyzes the degradation of heme to biliverdin. The crystal structure of human HO-1 in complex with heme reveals a novel helical structure with conserved glycines in the distal helix, providing flexibility to accommodate substrate binding and product release (Schuller, D. J., Wilks, A., Ortiz de Montellano, P. R., and Poulos, T. L. (1999) Nat. Struct. Biol. 6, 860-867). To structurally understand the HO catalytic pathway in more detail, we have determined the crystal structure of human apo-HO-1 at 2.1 A and a higher resolution structure of human HO-1 in complex with heme at 1.5 A. Although the 1.5-A heme.HO-1 model confirms our initial analysis based on the 2.08-A model, the higher resolution structure has revealed important new details such as a solvent H-bonded network in the active site that may be important for catalysis. Because of the absence of the heme, the distal and proximal helices that bracket the heme plane in the holo structure move farther apart in the apo structure, thus increasing the size of the active-site pocket. Nevertheless, the relative positioning and conformation of critical catalytic residues remain unchanged in the apo structure compared with the holo structure, but an important solvent H-bonded network is missing in the apoenzyme. It thus appears that the binding of heme and a tightening of the structure around the heme stabilize the solvent H-bonded network required for proper catalysis.


    Organizational Affiliation

    Department of Molecular Biology and Biochemistry, Program in Macromolecular Structure, University of California, Irvine 92697, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Heme oxygenase 1
A, B, C, D
224Homo sapiensMutation(s): 0 
Gene Names: HMOX1 (HO, HO1)
EC: 1.14.14.18
Find proteins for P09601 (Homo sapiens)
Go to Gene View: HMOX1
Go to UniProtKB:  P09601
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
TRE
Query on TRE

Download SDF File 
Download CCD File 
C
TREHALOSE
ALPHA-D-GLUCOPYRANOSYL-ALPHA-D-GLUCOPYRANOSIDE
C12 H22 O11
HDTRYLNUVZCQOY-LIZSDCNHSA-N
 Ligand Interaction
CL
Query on CL

Download SDF File 
Download CCD File 
C
CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.1 Å
  • R-Value Free: 0.267 
  • R-Value Work: 0.217 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 76.211α = 90.00
b = 55.507β = 98.88
c = 108.001γ = 90.00
Software Package:
Software NamePurpose
SCALEPACKdata scaling
MOLREPphasing
HKL-2000data reduction
HKL-2000data collection
CNSrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2003-04-01
    Type: Initial release
  • Version 1.1: 2008-04-29
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance