1IWH

Crystal Structure of Horse Carbonmonoxyhemoglobin-Bezafibrate Complex at 1.55A Resolution: A Novel Allosteric Binding Site in R-State Hemoglobin


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.55 Å
  • R-Value Free: 0.233 
  • R-Value Observed: 0.175 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

Crystal Structure of Horse Carbonmonoxyhemoglobin-Bezafibrate Complex at 1.55A Resolution. A Novel Allosteric Binding Site in R-State Hemoglobin

Shibayama, N.Miura, S.Tame, J.R.H.Yonetani, T.Park, S.-Y.

(2002) J Biol Chem 277: 38791-38796

  • DOI: 10.1074/jbc.M205461200
  • Primary Citation of Related Structures:  
    1IWH

  • PubMed Abstract: 
  • Bezafibrate, an antilipidemic drug, is known as a potent allosteric effector of hemoglobin. The previously proposed mechanism for the allosteric potency of this drug was that it stabilizes and constrains the T-state of hemoglobin by specifically bind ...

    Bezafibrate, an antilipidemic drug, is known as a potent allosteric effector of hemoglobin. The previously proposed mechanism for the allosteric potency of this drug was that it stabilizes and constrains the T-state of hemoglobin by specifically binding to the large central cavity of the T-state. Here we report a new allosteric binding site of fully liganded R-state hemoglobin for this drug. The high resolution crystal structure of horse carbonmonoxyhemoglobin in complex with bezafibrate reveals that the bezafibrate molecule lies near the surface of the E-helix of each alpha subunit and the complex maintains the quaternary structure of the R-state. Binding is caused by the close fit of bezafibrate into the binding pocket, which is composed of some hydrophobic residues and the heme edge, suggesting the importance of hydrophobic interactions. Upon binding of bezafibrate, the distance between Fe and the N epsilon(2) of distal His E7(alpha 58) is shortened by 0.22 A in the alpha subunit, whereas no significant structural changes are transmitted to the beta subunit. Oxygen equilibrium studies of R-state-locked hemoglobin with bezafibrate in a wet porous sol-gel indicate that bezafibrate selectively lowers the oxygen affinity of one type of subunit within the R-state, consistent with the structural data. These results disclose a new allosteric mechanism of bezafibrate and offer the first demonstration of how the allosteric effector interacts with R-state hemoglobin.


    Organizational Affiliation

    Department of Physiology, Division of Biophysics, Jichi Medical School, Yakushiji 3311-1, Minamikawachi, Kawachi, Tochigi 329-0498, Japan. shibayam@jichi.ac.jp



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
Hemoglobin beta chainB146Equus caballusMutation(s): 0 
Gene Names: HBB
Find proteins for P02062 (Equus caballus)
Explore P02062 
Go to UniProtKB:  P02062
Protein Feature View
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Hemoglobin alpha chainA141Equus caballusMutation(s): 0 
Gene Names: HBA
Find proteins for P01958 (Equus caballus)
Explore P01958 
Go to UniProtKB:  P01958
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
HEM
Query on HEM

Download CCD File 
A, B
PROTOPORPHYRIN IX CONTAINING FE
C34 H32 Fe N4 O4
KABFMIBPWCXCRK-RGGAHWMASA-L
 Ligand Interaction
PEM
Query on PEM

Download CCD File 
A
2-[P-[2-P-CHLOROBENZAMIDO)ETHYL]PHENOXY]-2-METHYLPROPIONIC ACID
C19 H20 Cl N O4
IIBYAHWJQTYFKB-UHFFFAOYSA-N
 Ligand Interaction
CMO
Query on CMO

Download CCD File 
A, B
CARBON MONOXIDE
C O
UGFAIRIUMAVXCW-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.55 Å
  • R-Value Free: 0.233 
  • R-Value Observed: 0.175 
  • Space Group: C 2 2 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 62.396α = 90
b = 107.496β = 90
c = 86.745γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
AMoREphasing
SHELXL-97refinement

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2002-10-02
    Type: Initial release
  • Version 1.1: 2008-04-27
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2011-11-16
    Changes: Atomic model