1CBL

THE 1.9 ANGSTROM STRUCTURE OF DEOXY-BETA4 HEMOGLOBIN: ANALYSIS OF THE PARTITIONING OF QUATERNARY-ASSOCIATED AND LIGAND-INDUCED CHANGES IN TERTIARY STRUCTURE


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.8 Å

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

The 1.9 A structure of deoxy beta 4 hemoglobin. Analysis of the partitioning of quaternary-associated and ligand-induced changes in tertiary structure.

Borgstahl, G.E.Rogers, P.H.Arnone, A.

(1994) J.Mol.Biol. 236: 831-843

  • DOI: 10.1006/jmbi.1994.1192

  • PubMed Abstract: 
  • The crystal structure of the deoxygenated form of the human hemoglobin beta 4 tetramer (deoxy beta 4) has been determined and refined at a resolution of 1.9 A. A detailed comparison of the quaternary structures of carbonmonoxy-beta 4 (CO beta 4) and ...

    The crystal structure of the deoxygenated form of the human hemoglobin beta 4 tetramer (deoxy beta 4) has been determined and refined at a resolution of 1.9 A. A detailed comparison of the quaternary structures of carbonmonoxy-beta 4 (CO beta 4) and deoxy beta 4 shows that ligand binding to the beta 4 tetramer produces only slight movements of the subunits relative to each other. Therefore, unlike the hemoglobin alpha 2 beta 2 tetramer, where the transition from an unliganded T state tetramer to a liganded R state tetramer results in a large change in quaternary structure, beta 4 is locked in a quaternary structure that very closely resembles the R state. By comparing the high-resolution structures of T state deoxy alpha 2 beta 2, R state deoxy beta 4 and R state CO beta 4, it is possible to partition the changes in beta subunit tertiary structure into those that arise from changes in quaternary structure and those that result solely from ligand binding. Specifically, when viewed from the heme reference frame, comparison of the structures of T state deoxy alpha 2 beta 2 and R state deoxy beta 4 shows that the T-to-R quaternary structure transition induces changes in beta subunit tertiary structure that are approximately halfway toward the tertiary structure observed in liganded beta 4 and liganded alpha 2 beta 2. When viewed from the reference frame of the globin backbone atoms, the T-to-R quaternary structure transition induces a small rotation of the heme group and a shift of the "allosteric core" (the end of the F helix, the FG corner, the beginning of the G helix, and the heme group) away from the E helix. These movements open the ligand binding pocket and place the heme in a more symmetric position relative to the proximal histidine residue. Together, these effects work in unison to give the subunits of deoxy beta 4 a tertiary structure that has high ligand affinity.


    Organizational Affiliation

    Department of Biochemistry, University of Iowa, Iowa City 52242.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
HEMOGLOBIN BETA 4 (DEOXY)
A, B, C, D
146Homo sapiensGene 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
SO4
Query on SO4

Download SDF File 
Download CCD File 
A, B, C, D
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
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
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 63.000α = 90.00
b = 81.800β = 89.70
c = 54.400γ = 90.00
Software Package:
Software NamePurpose
PROLSQrefinement
TNTrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1994-07-31
    Type: Initial release
  • Version 1.1: 2008-03-24
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Advisory, Version format compliance