1Y01

Crystal structure of AHSP bound to Fe(II) alpha-hemoglobin


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.8 Å
  • R-Value Free: 0.292 
  • R-Value Work: 0.273 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Molecular mechanism of AHSP-mediated stabilization of alpha-hemoglobin.

Feng, L.Gell, D.A.Zhou, S.Gu, L.Kong, Y.Li, J.Hu, M.Yan, N.Lee, C.Rich, A.M.Armstrong, R.S.Lay, P.A.Gow, A.J.Weiss, M.J.Mackay, J.P.Shi, Y.

(2004) Cell 119: 629-640

  • DOI: 10.1016/j.cell.2004.11.025
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Hemoglobin A (HbA), the oxygen delivery system in humans, comprises two alpha and two beta subunits. Free alpha-hemoglobin (alphaHb) is unstable, and its precipitation contributes to the pathophysiology of beta thalassemia. In erythrocytes, the alpha ...

    Hemoglobin A (HbA), the oxygen delivery system in humans, comprises two alpha and two beta subunits. Free alpha-hemoglobin (alphaHb) is unstable, and its precipitation contributes to the pathophysiology of beta thalassemia. In erythrocytes, the alpha-hemoglobin stabilizing protein (AHSP) binds alphaHb and inhibits its precipitation. The crystal structure of AHSP bound to Fe(II)-alphaHb reveals that AHSP specifically recognizes the G and H helices of alphaHb through a hydrophobic interface that largely recapitulates the alpha1-beta1 interface of hemoglobin. The AHSP-alphaHb interactions are extensive but suboptimal, explaining why beta-hemoglobin can competitively displace AHSP to form HbA. Remarkably, the Fe(II)-heme group in AHSP bound alphaHb is coordinated by the distal but not the proximal histidine. Importantly, binding to AHSP facilitates the conversion of oxy-alphaHb to a deoxygenated, oxidized [Fe(III)], nonreactive form in which all six coordinate positions are occupied. These observations reveal the molecular mechanisms by which AHSP stabilizes free alphaHb.


    Organizational Affiliation

    Department of Molecular Biology, Lewis Thomas Laboratory, Princeton University, Princeton, NJ 08544, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Alpha-hemoglobin stabilizing protein
A
102Homo sapiensMutations: P30A
Gene Names: AHSP (EDRF, ERAF)
Find proteins for Q9NZD4 (Homo sapiens)
Go to Gene View: AHSP
Go to UniProtKB:  Q9NZD4
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Hemoglobin alpha chain
B
142Homo sapiensGene Names: HBA1, HBA2
Find proteins for P69905 (Homo sapiens)
Go to Gene View: HBA1 HBA2
Go to UniProtKB:  P69905
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
OXY
Query on OXY

Download SDF File 
Download CCD File 
B
OXYGEN MOLECULE
O2
MYMOFIZGZYHOMD-UHFFFAOYSA-N
 Ligand Interaction
HEM
Query on HEM

Download SDF File 
Download CCD File 
B
PROTOPORPHYRIN IX CONTAINING FE
HEME
C34 H32 Fe N4 O4
KABFMIBPWCXCRK-RGGAHWMASA-L
 Ligand Interaction
CHK
Query on CHK

Download SDF File 
Download CCD File 
B
6-[(CYCLOHEXYLACETYL)(2-HYDROXYETHYL)AMINO]-6-DEOXY-D-XYLO-HEXITOL
C-HEGA-8, CYCLOHEXYLETHANOYL-N-HYDROXYETHYLGLUCOAMIDE
C16 H31 N O7
DIWWAIOQKLBBRJ-CLWVCHIJSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.8 Å
  • R-Value Free: 0.292 
  • R-Value Work: 0.273 
  • Space Group: P 41 21 2
Unit Cell:
Length (Å)Angle (°)
a = 69.630α = 90.00
b = 69.630β = 90.00
c = 140.466γ = 90.00
Software Package:
Software NamePurpose
CNSrefinement
DENZOdata reduction
SOLVEphasing
SCALEPACKdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2004-12-21
    Type: Initial release
  • Version 1.1: 2008-04-30
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance