1Y01

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


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.80 Å
  • R-Value Free: 0.292 
  • R-Value Work: 0.273 
  • R-Value Observed: 0.274 

wwPDB Validation   3D Report Full Report


This is version 1.3 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:  
    1XZY, 1Y01

  • 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 stabilizing protein (AHSP) binds alphaHb and inhibits its precipitation ...

    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:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Alpha-hemoglobin stabilizing proteinA102Homo sapiensMutation(s): 1 
Gene Names: AHSPEDRFERAF
UniProt & NIH Common Fund Data Resources
Find proteins for Q9NZD4 (Homo sapiens)
Explore Q9NZD4 
Go to UniProtKB:  Q9NZD4
PHAROS:  Q9NZD4
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ9NZD4
Protein Feature View
Expand
  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
Hemoglobin alpha chainB142Homo sapiensMutation(s): 0 
Gene Names: HBA1HBA2
UniProt & NIH Common Fund Data Resources
Find proteins for P69905 (Homo sapiens)
Explore P69905 
Go to UniProtKB:  P69905
PHAROS:  P69905
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP69905
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
HEM
Query on HEM

Download Ideal Coordinates CCD File 
C [auth B]PROTOPORPHYRIN IX CONTAINING FE
C34 H32 Fe N4 O4
KABFMIBPWCXCRK-RGGAHWMASA-L
 Ligand Interaction
CHK
Query on CHK

Download Ideal Coordinates CCD File 
E [auth B]6-[(CYCLOHEXYLACETYL)(2-HYDROXYETHYL)AMINO]-6-DEOXY-D-XYLO-HEXITOL
C16 H31 N O7
DIWWAIOQKLBBRJ-CLWVCHIJSA-N
 Ligand Interaction
OXY
Query on OXY

Download Ideal Coordinates CCD File 
D [auth B]OXYGEN MOLECULE
O2
MYMOFIZGZYHOMD-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.80 Å
  • R-Value Free: 0.292 
  • R-Value Work: 0.273 
  • R-Value Observed: 0.274 
  • Space Group: P 41 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 69.63α = 90
b = 69.63β = 90
c = 140.466γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
SOLVEphasing
CNSrefinement

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2004-12-21
    Type: Initial release
  • Version 1.1: 2008-04-30
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2021-10-20
    Changes: Database references, Derived calculations, Structure summary