1URV

Crystal structure of cytoglobin: the fourth globin type discovered in man displays heme hexa-coordination

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Free: 0.265 
  • R-Value Work: 0.219 

wwPDB Validation 3D Report Full Report


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

Literature

Crystal Structure of Cytoglobin: The Fourth Globin Type Discovered in Man Displays Heme Hexa-Coordination.

De Sanctis, D., Dewilde, S., Pesce, A., Moens, L., Ascenzi, P., Hankeln, T., Burmester, T., Bolognesi, M.

(2004) J.Mol.Biol. 336: 917

  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    • Cytoglobin is a recently discovered hemeprotein belonging to the globin superfamily together with hemoglobin, myoglobin and neuroglobin. Although distributed in almost all human tissues, cytoglobin has not been ascribed a specific function. Human cyt ...

    Cytoglobin is a recently discovered hemeprotein belonging to the globin superfamily together with hemoglobin, myoglobin and neuroglobin. Although distributed in almost all human tissues, cytoglobin has not been ascribed a specific function. Human cytoglobin is composed of 190 amino acid residues. Sequence alignments show that a protein core region (about 150 residues) is structurally related to hemoglobin and myoglobin, being complemented by about 20 extra residues both on the N and C termini. In the absence of exogenous ligands (e.g. O2), the cytoglobin distal HisE7 residue is coordinated to the heme Fe atom, thus decreasing the ligand affinity. The crystal structure of human cytoglobin (2.1 A resolution, 21.3% R-factor) highlights a three-over-three alpha-helical globin fold, covering residues 18-171; the 1-17 N-terminal, and the 172-190 C-terminal residue segments are disordered in both molecules of the crystal asymmetric unit. Heme hexa-coordination is evident in one of the two cytoglobin chains, whereas alternate conformation for the heme distal region, achieving partial heme penta-coordination, is observed in the other. Human cytoglobin displays a large apolar protein matrix cavity, next to the heme, not related to the myoglobin cavities recognized as temporary ligand docking stations. The cavity, which may provide a heme ligand diffusion pathway, is connected to the external space through a narrow tunnel nestled between the globin G and H helices.

    Organizational Affiliation: 

    Department of Physics-INFM, Centre for Excellence in Biomedical Research, University of Genova, Via Dodecaneso 33, 1-16146 Genova, Italy.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
CYTOGLOBIN
A, B
190Homo sapiensMutations: S83C, S38C
Gene Names: CYGB (STAP)
Find proteins for Q8WWM9 (Homo sapiens)
Go to Gene View: CYGB
Go to UniProtKB:  Q8WWM9
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
FC6
Query on FC6
Download SDF File 
Download CCD File 
A, B
HEXACYANOFERRATE(3-)
FERRI(III)HEXACYANIDE
C6 Fe N6
HCMVSLMENOCDCK-UHFFFAOYSA-N
 Ligand Interaction
HEM
Query on HEM
Download SDF File 
Download CCD File 
A, B
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: 2 Å
  • R-Value Free: 0.265 
  • R-Value Work: 0.219 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 48.940α = 90.00
b = 70.429β = 90.00
c = 100.913γ = 90.00
Software Package:
Software NamePurpose
REFMACrefinement
SCALAdata scaling
MOSFLMdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots


View more in-depth experimental data

Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2004-12-15
    Type: Initial release
  • Version 1.1: 2011-05-08
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance