1Z8U

Crystal structure of oxidized alpha hemoglobin bound to AHSP


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.4 Å
  • R-Value Free: 0.252 
  • R-Value Work: 0.222 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Structure of oxidized alpha-haemoglobin bound to AHSP reveals a protective mechanism for haem.

Feng, L.Zhou, S.Gu, L.Gell, D.A.Mackay, J.P.Weiss, M.J.Gow, A.J.Shi, Y.

(2005) Nature 435: 697-701

  • DOI: 10.1038/nature03609

  • PubMed Abstract: 
  • The synthesis of haemoglobin A (HbA) is exquisitely coordinated during erythrocyte development to prevent damaging effects from individual alpha- and beta-subunits. The alpha-haemoglobin-stabilizing protein (AHSP) binds alpha-haemoglobin (alphaHb), i ...

    The synthesis of haemoglobin A (HbA) is exquisitely coordinated during erythrocyte development to prevent damaging effects from individual alpha- and beta-subunits. The alpha-haemoglobin-stabilizing protein (AHSP) binds alpha-haemoglobin (alphaHb), inhibits the ability of alphaHb to generate reactive oxygen species and prevents its precipitation on exposure to oxidant stress. The structure of AHSP bound to ferrous alphaHb is thought to represent a transitional complex through which alphaHb is converted to a non-reactive, hexacoordinate ferric form. Here we report the crystal structure of this ferric alphaHb-AHSP complex at 2.4 A resolution. Our findings reveal a striking bis-histidyl configuration in which both the proximal and the distal histidines coordinate the haem iron atom. To attain this unusual conformation, segments of alphaHb undergo drastic structural rearrangements, including the repositioning of several alpha-helices. Moreover, conversion to the ferric bis-histidine configuration strongly and specifically inhibits redox chemistry catalysis and haem loss from alphaHb. The observed structural changes, which impair the chemical reactivity of haem iron, explain how AHSP stabilizes alphaHb and prevents its damaging effects in cells.


    Organizational Affiliation

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




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Alpha-hemoglobin stabilizing protein
A, C
102Homo sapiensMutation(s): 1 
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, D
142Homo sapiensMutation(s): 0 
Gene Names: HBA1, HBA2
Find proteins for P69905 (Homo sapiens)
Go to Gene View: HBA1 HBA2
Go to UniProtKB:  P69905
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
HEM
Query on HEM

Download SDF File 
Download CCD File 
B, D
PROTOPORPHYRIN IX CONTAINING FE
HEME
C34 H32 Fe N4 O4
KABFMIBPWCXCRK-RGGAHWMASA-L
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.4 Å
  • R-Value Free: 0.252 
  • R-Value Work: 0.222 
  • Space Group: C 1 2 1
Unit Cell:
Length (Å)Angle (°)
a = 65.808α = 90.00
b = 113.747β = 94.66
c = 80.098γ = 90.00
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
SOLVEphasing
CNSrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2005-06-14
    Type: Initial release
  • Version 1.1: 2008-04-30
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance