1YEU

T-To-T(High) quaternary transitions in human hemoglobin: betaW37G OXY (10 test sets)


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.12 Å
  • R-Value Free: 0.254 
  • R-Value Work: 0.201 
  • R-Value Observed: 0.206 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Crystallographic evidence for a new ensemble of ligand-induced allosteric transitions in hemoglobin: the T-to-T(high) quaternary transitions.

Kavanaugh, J.S.Rogers, P.H.Arnone, A.

(2005) Biochemistry 44: 6101-6121

  • DOI: 10.1021/bi047813a
  • Structures With Same Primary Citation

  • PubMed Abstract: 
  • A detailed description of hemoglobin cooperativity requires knowledge of the dimer-dimer interactions responsible for the low ligand affinity of the quaternary-T tetramer, the "quaternary-T constraints", along with stereochemical pathways that specif ...

    A detailed description of hemoglobin cooperativity requires knowledge of the dimer-dimer interactions responsible for the low ligand affinity of the quaternary-T tetramer, the "quaternary-T constraints", along with stereochemical pathways that specify how ligand binding disrupts these quaternary constraints. The recent mutagenic screen of Noble et al. [Noble, R. W., et al. (2001) Biochemistry 40, 12357-12368] has identified the major region of quaternary constraint to be a cluster of residues at the alpha1beta2 interface that is centered at Trp37beta. In this paper, crystallographic studies are presented for most of the mutant hemoglobins studied by Noble et al. These crystallographic experiments identify structural transitions-referred to as T-to-T(High) transitions-between the quaternary-T structure of wild-type deoxyhemoglobin and an ensemble of related T-like quaternary structures that are induced by some mutations in the Trp37beta cluster and/or by exposing crystals of wild-type or mutant deoxyhemoglobins to oxygen. The T-to-T(High) quaternary transitions consist of a rotation of the alpha1beta1 dimer relative to the alpha2beta2 dimer as well as a coupled alphabeta dimer bending component that consists of a small rotation of the alpha1 subunit relative to the beta1 subunit (and a symmetry related rotation of the alpha2 subunit relative to the beta2 subunit). In addition, differences in subunit tertiary structure associated with the T-to-T(High) transitions suggest two stereochemical pathways (one associated with the alpha subunits and one associated with the betasubunits) by which ligand binding specifically disrupts quaternary constraints in the Trp37beta cluster. In the alpha subunits, ligand binding induces a shift of the heme iron producing tension in a chain of covalent bonds that extends from the Fe-N(epsilon)(2)His(F8)alpha1 bond to the peptide backbone bonds of residues His87(F8)alpha1 and Ala88(F9)alpha1. This tension induces an alpha-to-pi transition in the COOH-terminal end of the F-helix that shifts the beta-carbon of Ala88alpha1 by approximately 1.5 A directly into the side chain of Tyr140alpha1 (a key residue in the Trp37beta2 cluster). Collectively these structural changes constitute a relatively short pathway by which ligand binding forces Tyr140alpha1 into the alpha1beta2 interface disrupting quaternary constraints associated with the Trp37beta2 cluster. In the beta subunits, our analysis suggests a more extended energy transduction pathway in which ligand-induced beta1-heme movement triggers tertiary changes in the beta1 subunit that promote alpha1beta1 dimer bending that disrupts quaternary constraints in the Trp37beta2 cluster at the alpha1beta2 interface.


    Organizational Affiliation

    Department of Biochemistry, Roy J. and Lucille A. Carver College of Medicine, The University of Iowa, Iowa City, Iowa 52242, USA.



Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Hemoglobin alpha chainA, C141Homo sapiensMutation(s): 0 
Gene Names: HBA1HBA2
Find proteins for P69905 (Homo sapiens)
Explore P69905 
Go to UniProtKB:  P69905
NIH Common Fund Data Resources
PHAROS  P69905
Protein Feature View
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  • Reference Sequence

Find similar proteins by: Sequence  |  Structure

Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Hemoglobin beta chainB, D146Homo sapiensMutation(s): 2 
Gene Names: HBB
Find proteins for P68871 (Homo sapiens)
Explore P68871 
Go to UniProtKB:  P68871
NIH Common Fund Data Resources
PHAROS  P68871
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
HEM
Query on HEM

Download CCD File 
A, B, C, D
PROTOPORPHYRIN IX CONTAINING FE
C34 H32 Fe N4 O4
KABFMIBPWCXCRK-RGGAHWMASA-L
 Ligand Interaction
OXY
Query on OXY

Download CCD File 
A, B, C, D
OXYGEN MOLECULE
O2
MYMOFIZGZYHOMD-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.12 Å
  • R-Value Free: 0.254 
  • R-Value Work: 0.201 
  • R-Value Observed: 0.206 
  • Space Group: P 21 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 96.25α = 90
b = 99.22β = 90
c = 66.89γ = 90
Software Package:
Software NamePurpose
SDMSdata collection
SDMSdata reduction
X-PLORmodel building
REFMACrefinement
SDMSdata scaling
X-PLORphasing

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2005-01-11
    Type: Initial release
  • Version 1.1: 2008-04-30
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance