1NEJ

Crystalline Human Carbonmonoxy Hemoglobin S (Liganded Sickle Cell Hemoglobin) Exhibits The R2 Quaternary State At Neutral pH In The Presence Of Polyethylene Glycol: The 2.1 Angstrom Resolution Crystal Structure

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.1 Å
  • R-Value Free: 0.268 
  • R-Value Work: 0.235 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history. 

Literature

COHbC and COHbS crystallize in the R2 quaternary state at neutral pH in the presence of PEG 4000.

Patskovska, L.N., Patskovsky, Y.V., Almo, S.C., Hirsch, R.E.

(2005) Acta Crystallogr.,Sect.D 61: 566-573

  • DOI: 10.1107/S0907444905004622
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    • Human hemoglobin binds oxygen cooperatively and functions as a tetramer composed of two identical alphabeta heterodimers. While human hemoglobin is the best characterized allosteric protein, the quaternary R (oxygenated or liganded) to T (deoxygenate ...

    Human hemoglobin binds oxygen cooperatively and functions as a tetramer composed of two identical alphabeta heterodimers. While human hemoglobin is the best characterized allosteric protein, the quaternary R (oxygenated or liganded) to T (deoxygenated) structural transition remains controversial. The R2 state has been postulated to represent either an intermediate or final quaternary state elicited by ligand binding. However, the biological relevance of the R2 state has been questioned as it has not been observed crystallographically under physiological conditions. The high-resolution R2 quaternary structures of human COHbC (betaE6K) and COHbS (betaE6V) are reported at neutral pH and low ionic strength using PEG 4000 as a precipitant. Crystals of COHbC, COHbS and their mixtures are isomorphous, indicating that they share the same tertiary and quaternary structures. In contrast, oxyHbA or COHbA did not yield crystals at neutral pH under similar conditions. Solubility studies and modeling suggest that at neutral pH and low ionic strength the beta6 mutant hemoglobins crystallize (betaK6 > betaV6) as a result of more favorable lattice contacts.

    Organizational Affiliation: 

    Department of Medicine (Division of Hematology), Albert Einstein College of Medicine, Bronx, New York, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Hemoglobin alpha chain
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 beta chain
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 2 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
CMO
Query on CMO
Download SDF File 
Download CCD File 
A, B, C, D
CARBON MONOXIDE
C O
UGFAIRIUMAVXCW-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.1 Å
  • R-Value Free: 0.268 
  • R-Value Work: 0.235 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 58.000α = 90.00
b = 58.530β = 90.00
c = 171.840γ = 90.00
Software Package:
Software NamePurpose
DENZOdata reduction
X-PLORphasing
SCALEPACKdata scaling
X-PLORmodel building
X-PLORrefinement

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2003-12-16
    Type: Initial release
  • Version 1.1: 2008-04-28
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance