1J7S

Crystal Structure of deoxy HbalphaYQ, a mutant of HbA


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.210 
  • R-Value Work: 0.160 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Control of heme reactivity by diffusion: structural basis and functional characterization in hemoglobin mutants.

Miele, A.E.Draghi, F.Arcovito, A.Bellelli, A.Brunori, M.Travaglini-Allocatelli, C.Vallone, B.

(2001) Biochemistry 40: 14449-14458

  • Primary Citation of Related Structures:  1J7W, 1J7Y

  • PubMed Abstract: 
  • The effect of mutagenesis on O(2), CO, and NO binding to mutants of human hemoglobin, designed to modify some features of the reactivity that hinder use of hemoglobin solutions as blood substitute, has been extensively investigated. The kinetics may ...

    The effect of mutagenesis on O(2), CO, and NO binding to mutants of human hemoglobin, designed to modify some features of the reactivity that hinder use of hemoglobin solutions as blood substitute, has been extensively investigated. The kinetics may be interpreted in the framework of the Monod-Wyman-Changeux two-state allosteric model, based on the high-resolution crystallographic structures of the mutants and taking into account the control of heme reactivity by the distal side mutations. The mutations involve residues at topological position B10 and E7, i.e., Leu (B10) to Tyr and His (E7) to Gln, on either the alpha chains alone (yielding the hybrid tetramer Hbalpha(YQ)), the beta chains alone (hybrid tetramer Hbbeta(YQ)), or both types of chains (Hb(YQ)). Our data indicate that the two mutations affect ligand diffusion into the pocket, leading to proteins with low affinity for O(2) and CO, and especially with reduced reactivity toward NO, a difficult goal to achieve. The observed kinetic heterogeneity between the alpha(YQ) and beta(YQ) chains in Hb(YQ) has been rationalized on the basis of the three-dimensional structure of the active site. Furthermore, we report for the first time an experiment of partial CO binding, selective for the beta chains, to high salt crystals of the mutant Hb(YQ) in the T-state; these crystallographic data may be interpreted as "snapshots" of the initial events possibly occurring on ligand binding to the T-allosteric state of this peculiar mutant Hb.


    Organizational Affiliation

    Department of Biochemical Sciences "A. Rossi Fanelli" and CNR Centre for Molecular Biology, University of Rome "La Sapienza", P.le A. Moro 5, 00185 Rome, Italy.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Hemoglobin
A, C
141Homo sapiensGene Names: HBA1, HBA2
Find proteins for P69905 (Homo sapiens)
Go to Gene View: HBA1 HBA2
Go to UniProtKB:  P69905
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Hemoglobin
B, D
146Homo sapiensGene Names: HBB
Find proteins for P68871 (Homo sapiens)
Go to Gene View: HBB
Go to UniProtKB:  P68871
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
HEM
Query on HEM

Download SDF File 
Download CCD File 
A, B, C, 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: 2.2 Å
  • R-Value Free: 0.210 
  • R-Value Work: 0.160 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 63.360α = 90.00
b = 84.320β = 99.43
c = 54.000γ = 90.00
Software Package:
Software NamePurpose
SCALEPACKdata scaling
DENZOdata reduction
REFMACrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2002-02-27
    Type: Initial release
  • Version 1.1: 2008-04-27
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2017-10-04
    Type: Advisory, Refinement description