The X-ray structure of the cyanobacteria Synechocystis hemoglobin "cyanoglobin" with azide ligand

Experimental Data Snapshot

  • Resolution: 1.69 Å
  • R-Value Free: 0.219 
  • R-Value Work: 0.197 
  • R-Value Observed: 0.198 

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Crystallographic analysis of synechocystis cyanoglobin reveals the structural changes accompanying ligand binding in a hexacoordinate hemoglobin.

Trent III, J.T.Kundu, S.Hoy, J.A.Hargrove, M.S.

(2004) J Mol Biol 341: 1097-1108

  • DOI: https://doi.org/10.1016/j.jmb.2004.05.070
  • Primary Citation of Related Structures:  
    1S69, 1S6A

  • PubMed Abstract: 

    The crystal structures of cyanide and azide-bound forms of the truncated hemoglobin from Synechocystis are presented at 1.8 angstroms resolution. A comparison with the structure of the endogenously liganded protein reveals a conformational shift unprecedented in hemoglobins, and provides the first picture of a hexacoordinate hemoglobin in both the bis-histidyl and the exogenously coordinated states. The structural changes between the different conformations are confined to two regions of the protein; the B helix, and the E helix, including the EF loop. A molecular "hinge" controlling movement of the E helix is observed in the EF loop, which is composed of three principal structural elements: Arg64, the heme-d-propionate, and a three-residue extension of the F helix. Additional features of the structural transition between the two protein conformations are discussed as they relate to the complex ligand-binding behavior observed in hexacoordinate hemoglobins, and the potential physiological function of this class of proteins.

  • Organizational Affiliation

    Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA 50010, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Cyanoglobin124Synechocystis sp. PCC 6803Mutation(s): 0 
Gene Names: GLBNSLR2097
Find proteins for P73925 (Synechocystis sp. (strain PCC 6803 / Kazusa))
Explore P73925 
Go to UniProtKB:  P73925
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP73925
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 1.69 Å
  • R-Value Free: 0.219 
  • R-Value Work: 0.197 
  • R-Value Observed: 0.198 
  • Space Group: I 41
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 83.35α = 90
b = 83.35β = 90
c = 65.18γ = 90
Software Package:
Software NamePurpose
CRYSTALdata reduction
d*TREKdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2004-09-21
    Type: Initial release
  • Version 1.1: 2008-04-29
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Source and taxonomy, Version format compliance
  • Version 1.3: 2023-08-23
    Changes: Data collection, Database references, Derived calculations, Refinement description