1D2U

1.15 A CRYSTAL STRUCTURE OF NITROPHORIN 4 FROM RHODNIUS PROLIXUS


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.15 Å
  • R-Value Free: 0.190 
  • R-Value Work: 0.130 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Ligand-induced heme ruffling and bent no geometry in ultra-high-resolution structures of nitrophorin 4.

Roberts, S.A.Weichsel, A.Qiu, Y.Shelnutt, J.A.Walker, F.A.Montfort, W.R.

(2001) Biochemistry 40: 11327-11337

  • Primary Citation of Related Structures:  1IKE, 1IKJ, 1KOI
  • Also Cited By: 1T68, 3FLL

  • PubMed Abstract: 
  • The nitrophorins are a family of proteins that use ferric heme to transport nitric oxide (NO) from the salivary glands of blood-sucking insects to their victims, resulting in vasodilation and reduced blood coagulation. We have refined atomic resoluti ...

    The nitrophorins are a family of proteins that use ferric heme to transport nitric oxide (NO) from the salivary glands of blood-sucking insects to their victims, resulting in vasodilation and reduced blood coagulation. We have refined atomic resolution structures of nitrophorin 4 (NP4) from Rhodnius prolixus complexed with NO (1.08 A) and NH(3) (1.15 A), yielding a highly detailed picture of the iron coordination sphere. In NP4-NO, the NO nitrogen is coordinated to iron (Fe-N distance = 1.66 A) and is somewhat bent (Fe-N-O angle = 156 degrees ), with bending occurring in the same plane as the proximal histidine ring. The Fe(NO)(heme)(His) coordination geometry is unusual but consistent with an Fe(III) oxidation state that is stabilized by a highly ruffled heme. Heme ruffling occurs in both structures, apparently due to close contacts between the heme and leucines 123 and 133, but increases on binding NO even though the steric contacts have not changed. We also report the structure of NP4 in complexes with histamine (1.50 A) and imidazole (1.27 A). Unexpectedly, two mobile loops that rearrange to pack against the bound NO in NP4-NO, also rearrange in the NP4-imidazole complex. This conformational change is apparently driven by the nonpolar nature of the NO and imidazole (as bound) ligands. Taken together, the desolvation of the NO binding pocket through a change in protein conformation, and the bending of the NO moiety, possibly through protein-assisted heme ruffling, may lead to a nitrosyl-heme complex that is unusually resistant to autoreduction.


    Organizational Affiliation

    Department of Biochemistry and Molecular Biophysics, University of Arizona, Tucson, Arizona 85721, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
NITROPHORIN 4
A
184Rhodnius prolixusEC: 1.7.6.1
Find proteins for Q94734 (Rhodnius prolixus)
Go to UniProtKB:  Q94734
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
HEM
Query on HEM

Download SDF File 
Download CCD File 
A
PROTOPORPHYRIN IX CONTAINING FE
HEME
C34 H32 Fe N4 O4
KABFMIBPWCXCRK-RGGAHWMASA-L
 Ligand Interaction
NH3
Query on NH3

Download SDF File 
Download CCD File 
A
AMMONIA
H3 N
QGZKDVFQNNGYKY-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.15 Å
  • R-Value Free: 0.190 
  • R-Value Work: 0.130 
  • Space Group: C 1 2 1
Unit Cell:
Length (Å)Angle (°)
a = 69.920α = 90.00
b = 42.690β = 93.82
c = 52.750γ = 90.00
Software Package:
Software NamePurpose
SCALEPACKdata scaling
SHELXL-97refinement
DENZOdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2001-10-03
    Type: Initial release
  • Version 1.1: 2008-04-27
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance