4N7O

Capturing the haemoglobin allosteric transition in a single crystal form; Crystal structure of half-liganded human haemoglobin with phosphate at 2.5 A resolution.


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Free: 0.292 
  • R-Value Work: 0.267 

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This is version 1.1 of the entry. See complete history


Literature

Capturing the hemoglobin allosteric transition in a single crystal form

Shibayama, N.Sugiyama, K.Tame, J.R.Park, S.Y.

(2014) J Am Chem Soc 136: 5097-5105

  • DOI: 10.1021/ja500380e
  • Primary Citation of Related Structures:  
    4N7N, 4N7O, 4N7P

  • PubMed Abstract: 
  • Allostery in many oligomeric proteins has been postulated to occur via a ligand-binding-driven conformational transition from the tense (T) to relaxed (R) state, largely on the basis of the knowledge of the structure and function of hemoglobin, the most thoroughly studied of all allosteric proteins ...

    Allostery in many oligomeric proteins has been postulated to occur via a ligand-binding-driven conformational transition from the tense (T) to relaxed (R) state, largely on the basis of the knowledge of the structure and function of hemoglobin, the most thoroughly studied of all allosteric proteins. However, a growing body of evidence suggests that hemoglobin possesses a variety of intermediates between the two end states. As such intermediate forms coexist with the end states in dynamic equilibrium and cannot be individually characterized by conventional techniques, very little is known about their properties and functions. Here we present complete structural and functional snapshots of nine equilibrium conformers of human hemoglobin in the half-liganded and fully liganded states by using a novel combination of X-ray diffraction analysis and microspectrophotometric O2 equilibrium measurements on three isomorphous crystals, each capturing three distinct equilibrium conformers. Notably, the conformational set of this crystal form varies according to shifts in the allosteric equilibrium, reflecting the differences in hemoglobin ligation state and crystallization solution conditions. We find that nine snapshot structures cover the complete conformational space of hemoglobin, ranging from T to R2 (the second relaxed quaternary structure) through R, with various relaxed intermediate forms between R and R2. Moreover, we find a previously unidentified intermediate conformer, between T and R, with an intermediate O2 affinity, sought by many research groups over a period of decades. These findings reveal a comprehensive picture of the equilibrium conformers and transition pathway for human hemoglobin.


    Organizational Affiliation

    Division of Biophysics, Department of Physiology, Jichi Medical University , 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Hemoglobin subunit alphaA, C, E, G, I, K141Homo 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:  (by identity cutoff)  |  Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
Hemoglobin subunit betaB, D, F, H, J, L146Homo sapiensMutation(s): 0 
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
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Free: 0.292 
  • R-Value Work: 0.267 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 228.935α = 90
b = 54.337β = 103.22
c = 137.884γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
PHASERphasing
PHENIXrefinement
PDB_EXTRACTdata extraction
HKL-2000data collection
CNSrefinement

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2014-04-02
    Type: Initial release
  • Version 1.1: 2014-04-23
    Changes: Database references