2O5Q

Manganese horse heart myoglobin, nitric oxide modified


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.9 Å
  • R-Value Free: 0.235 
  • R-Value Work: 0.177 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Crystal structures of manganese- and cobalt-substituted myoglobin in complex with NO and nitrite reveal unusual ligand conformations.

Zahran, Z.N.Chooback, L.Copeland, D.M.West, A.H.Richter-Addo, G.B.

(2008) J.Inorg.Biochem. 102: 216-233

  • DOI: 10.1016/j.jinorgbio.2007.08.002
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Nitrite is now recognized as a storage pool of bioactive nitric oxide (NO). Hemoglobin (Hb) and myoglobin (Mb) convert, under certain conditions, nitrite to NO. This newly discovered nitrite reductase activity of Hb and Mb provides an attractive alte ...

    Nitrite is now recognized as a storage pool of bioactive nitric oxide (NO). Hemoglobin (Hb) and myoglobin (Mb) convert, under certain conditions, nitrite to NO. This newly discovered nitrite reductase activity of Hb and Mb provides an attractive alternative to mammalian NO synthesis from the NO synthase pathway that requires dioxygen. We recently reported the X-ray crystal structure of the nitrite adduct of ferric horse heart Mb, and showed that the nitrite ligand binds in an unprecedented O-binding (nitrito) mode to the d(5) ferric center in Mb(III)(ONO) [D.M. Copeland, A. Soares, A.H. West, G.B. Richter-Addo, J. Inorg. Biochem. 100 (2006) 1413-1425]. We also showed that the distal pocket in Mb allows for different conformations of the NO ligand (120 degrees and 144 degrees ) in Mb(II)NO depending on the mode of preparation of the compound. In this article, we report the crystal structures of the nitrite and NO adducts of manganese-substituted hh Mb (a d(4) system) and of the nitrite adduct of cobalt-substituted hh Mb (a d(6) system). We show that the distal His64 residue directs the nitrite ligand towards the rare nitrito O-binding mode in Mn(III)Mb and Co(III)Mb. We also report that the distal pocket residues allow a stabilization of an unprecendented bent MnNO moiety in Mn(II)MbNO. These crystal structural data, when combined with the data for the aquo, methanol, and azide MnMb derivatives, provide information on the role of distal pocket residues in the observed binding modes of nitrite and NO ligands to wild-type and metal-substituted Mb.


    Organizational Affiliation

    The Department of Chemistry and Biochemistry, University of Oklahoma, 620 Parrington Oval, Norman, OK 73019, United States.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Myoglobin
X
153Equus caballusMutation(s): 0 
Gene Names: MB
Find proteins for P68082 (Equus caballus)
Go to Gene View: MB
Go to UniProtKB:  P68082
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SO4
Query on SO4

Download SDF File 
Download CCD File 
X
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
MNH
Query on MNH

Download SDF File 
Download CCD File 
X
MANGANESE PROTOPORPHYRIN IX
C34 H32 Mn N4 O4
UIBYYPDLEONCGQ-RGGAHWMASA-L
 Ligand Interaction
NO
Query on NO

Download SDF File 
Download CCD File 
X
NITRIC OXIDE
Nitrogen monoxide
N O
ODUCDPQEXGNKDN-UHFFFAOYAM
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.9 Å
  • R-Value Free: 0.235 
  • R-Value Work: 0.177 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 35.468α = 90.00
b = 28.637β = 105.70
c = 63.193γ = 90.00
Software Package:
Software NamePurpose
CrystalCleardata collection
MOLREPphasing
REFMACrefinement
d*TREKdata reduction
d*TREKdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2007-10-16
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance