3IA3

A cis-proline in alpha-hemoglobin stabilizing Protein directs the structural reorganization of alpha-hemoglobin


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.2 Å
  • R-Value Free: 0.293 
  • R-Value Work: 0.230 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

A cis-proline in alpha-hemoglobin stabilizing protein directs the structural reorganization of alpha-hemoglobin.

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

(2009) J.Biol.Chem. 284: 29462-29469

  • DOI: 10.1074/jbc.M109.027045

  • PubMed Abstract: 
  • alpha-Hemoglobin (alphaHb) stabilizing protein (AHSP) is expressed in erythropoietic tissues as an accessory factor in hemoglobin synthesis. AHSP forms a specific complex with alphaHb and suppresses the heme-catalyzed evolution of reactive oxygen spe ...

    alpha-Hemoglobin (alphaHb) stabilizing protein (AHSP) is expressed in erythropoietic tissues as an accessory factor in hemoglobin synthesis. AHSP forms a specific complex with alphaHb and suppresses the heme-catalyzed evolution of reactive oxygen species by converting alphaHb to a conformation in which the heme is coordinated at both axial positions by histidine side chains (bis-histidyl coordination). Currently, the detailed mechanism by which AHSP induces structural changes in alphaHb has not been determined. Here, we present x-ray crystallography, NMR spectroscopy, and mutagenesis data that identify, for the first time, the importance of an evolutionarily conserved proline, Pro(30), in loop 1 of AHSP. Mutation of Pro(30) to a variety of residue types results in reduced ability to convert alphaHb. In complex with alphaHb, AHSP Pro(30) adopts a cis-peptidyl conformation and makes contact with the N terminus of helix G in alphaHb. Mutations that stabilize the cis-peptidyl conformation of free AHSP, also enhance the alphaHb conversion activity. These findings suggest that AHSP loop 1 can transmit structural changes to the heme pocket of alphaHb, and, more generally, highlight the importance of cis-peptidyl prolyl residues in defining the conformation of regulatory protein loops.


    Organizational Affiliation

    School of Molecular and Microbial Biosciences, University of Sydney, New South Wales 2006, Australia. dagell@mail.usyd.edu.au




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Alpha-hemoglobin-stabilizing protein
A, C
91Homo sapiensMutation(s): 0 
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 subunit alpha
B, D
145Homo 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: 3.2 Å
  • R-Value Free: 0.293 
  • R-Value Work: 0.230 
  • Space Group: P 61 2 2
Unit Cell:
Length (Å)Angle (°)
a = 65.230α = 90.00
b = 65.230β = 90.00
c = 439.660γ = 120.00
Software Package:
Software NamePurpose
CBASSdata collection
PHASERphasing
DENZOdata reduction
SCALEPACKdata scaling
CNSrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2009-07-28
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance