1GBV

(ALPHA-OXY, BETA-(C112G)DEOXY) T-STATE HUMAN HEMOGLOBIN


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.00 Å
  • R-Value Work: 0.184 

wwPDB Validation   3D Report Full Report


This is version 1.5 of the entry. See complete history


Literature

Cysteines beta93 and beta112 as probes of conformational and functional events at the human hemoglobin subunit interfaces.

Vasquez, G.B.Karavitis, M.Ji, X.Pechik, I.Brinigar, W.S.Gilliland, G.L.Fronticelli, C.

(1999) Biophys J 76: 88-97

  • DOI: https://doi.org/10.1016/S0006-3495(99)77180-8
  • Primary Citation of Related Structures:  
    1GBU, 1GBV

  • PubMed Abstract: 

    Three variants of tetrameric human hemoglobin, with changes at the alpha1beta2/alpha2beta1-interface, at the alpha1beta1/alpha2beta2-interface, and at both interfaces, have been constructed. At alpha1beta2/alpha2beta1-interface the beta93 cysteine was replaced by alanine (betaC93A), and at the alpha1beta1/alpha2beta2-interface the beta112 cysteine was replaced by glycine (betaC112G). The alpha1beta2 interface variant, betaC93A, and the alpha1beta1/alpha1beta2 double mutant, beta(C93A+C112G), were crystallized in the T-state, and the structures determined at 2. 0 and 1.8 A resolution, respectively. A comparison of the structures with that of natural hemoglobin A shows the absence of detectable changes in the tertiary folding of the protein or in the T-state quaternary assembly. At the beta112 site, the void left by the removal of the cysteine side chain is filled by a water molecule, and the functional characteristics of betaC112G are essentially those of human hemoglobin A. At the beta93 site, water molecules do not replace the cysteine side chain, and the alanine substitution increases the conformational freedom of beta146His, weakening the important interaction of this residue with beta94Asp. As a result, when Cl- is present in the solution, at a concentration 100 mM, the Bohr effect of the two mutants carrying the beta93Cys-->Ala substitution, betaC93A and beta(C93A+C112G), is significantly modified being practically absent below pH 7.4. Based on the crystallographic data, we attribute these effects to the competition between beta94Asp and Cl- in the salt link with beta146His in T-state hemoglobin. These results point to an interplay between the betaHis146-betaAsp94 salt bridge and the Cl- in solution regulated by the Cys present at position beta93, indicating yet another role of beta93 Cys in the regulation of hemoglobin function.


  • Organizational Affiliation

    Center for Advanced Research in Biotechnology of the University of Maryland Biotechnology Institute and National Institute of Standards and Technology, Rockville, Maryland 20850, USA.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
HEMOGLOBIN
A, C
141Homo sapiensMutation(s): 0 
UniProt & NIH Common Fund Data Resources
Find proteins for P69905 (Homo sapiens)
Explore P69905 
Go to UniProtKB:  P69905
PHAROS:  P69905
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP69905
Sequence Annotations
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
HEMOGLOBIN
B, D
146Homo sapiensMutation(s): 1 
UniProt & NIH Common Fund Data Resources
Find proteins for P68871 (Homo sapiens)
Explore P68871 
Go to UniProtKB:  P68871
PHAROS:  P68871
GTEx:  ENSG00000244734 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP68871
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.00 Å
  • R-Value Work: 0.184 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 63.18α = 90
b = 83.56β = 99.6
c = 53.73γ = 90
Software Package:
Software NamePurpose
PROLSQrefinement
GPRLSArefinement
XENGENdata reduction

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 1997-01-11
    Type: Initial release
  • Version 1.1: 2008-03-24
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2019-07-17
    Changes: Data collection, Other, Refinement description
  • Version 1.4: 2021-11-03
    Changes: Database references, Derived calculations
  • Version 1.5: 2023-08-30
    Changes: Data collection, Database references, Structure summary