1QI8

DEOXYGENATED STRUCTURE OF A DISTAL POCKET HEMOGLOBIN MUTANT


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.8 Å
  • R-Value Free: 0.222 
  • R-Value Work: 0.169 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Modulation of ligand binding in engineered human hemoglobin distal pocket.

Miele, A.E.Santanche, S.Travaglini-Allocatelli, C.Vallone, B.Brunori, M.Bellelli, A.

(1999) J.Mol.Biol. 290: 515-524

  • DOI: 10.1006/jmbi.1999.2869

  • PubMed Abstract: 
  • Functional and structural studies on hemoglobin and myoglobin from different animals and engineered variants have enlightened the great importance of the physico-chemical properties of the side-chains at topological position B10 and E7. These residue ...

    Functional and structural studies on hemoglobin and myoglobin from different animals and engineered variants have enlightened the great importance of the physico-chemical properties of the side-chains at topological position B10 and E7. These residues proved to be crucial to the discrimination and stabilisation of gaseous ligands. In view of the data obtained on the high oxygen affinity hemoglobin from Ascaris worms and a new mutant of sperm whale myoglobin, we selected the two mutations Leu B10-->Tyr and His E7-->Gln as potentially relevant to control ligand binding parameters in the alpha and beta-chains of human hemoglobin. Here, we present an investigation of three new mutants: HbalphaYQ (alpha2YQbeta2A), HbbetaYQ (alpha2Abeta2YQ) and HbalphabetaYQ (alpha2YQbeta2YQ). They are characterised by a very low reactivity for NO, O2 and CO, and a reduced cooperativity. Their functional properties are not inconsistent with the behaviour expected for a two-state allosteric model. Proteins with these substitutions may be considered as candidates for the synthesis of a possible "blood substitute", which should yield an O2 adduct stable to autoxidation and slowly reacting with NO. The mutant HbalphabetaYQ is particularly interesting because the rate of reaction of NO with the oxy and deoxy derivatives is reduced. A structural interpretation of our data is presented based on the 3D structure of deoxy HbalphabetaYQ determined by crystallography at 1.8 A resolution.


    Organizational Affiliation

    Department of Biochemical Sciences and C.N.R. Centre of Molecular Biology, University of Rome "La Sapienza", P.le A. Moro, 5, Rome, 00185, Italy.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
HEMOGLOBIN
A, C
141Homo sapiensMutation(s): 0 
Gene 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 sapiensMutation(s): 0 
Gene 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: 1.8 Å
  • R-Value Free: 0.222 
  • R-Value Work: 0.169 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 63.360α = 90.00
b = 94.320β = 99.43
c = 54.000γ = 90.00
Software Package:
Software NamePurpose
SCALEPACKdata scaling
REFMACrefinement
DENZOdata reduction
AMoREphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1999-07-11
    Type: Initial release
  • Version 1.1: 2008-04-26
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance