1EUO

Crystal structure of nitrophorin 2 (prolixin-S)


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Free: 0.246 
  • R-Value Work: 0.195 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

The crystal structure of nitrophorin 2. A trifunctional antihemostatic protein from the saliva of Rhodnius prolixus

Andersen, J.F.Montfort, W.R.

(2000) J.Biol.Chem. 275: 30496-30503

  • DOI: 10.1074/jbc.M002857200
  • Also Cited By: 1T68, 2A3F, 2ACP, 2AH7, 2AL0, 2ALL, 2AMM, 2ASN, 2EU7, 2GTF, 2HYS

  • PubMed Abstract: 
  • Nitrophorin 2 (NP2) (also known as prolixin-S) is a salivary protein that transports nitric oxide, binds histamine, and acts as an anticoagulant during blood feeding by the insect Rhodnius prolixus. The 2.0-A crystal structure of NP2 reveals an eight ...

    Nitrophorin 2 (NP2) (also known as prolixin-S) is a salivary protein that transports nitric oxide, binds histamine, and acts as an anticoagulant during blood feeding by the insect Rhodnius prolixus. The 2.0-A crystal structure of NP2 reveals an eight-stranded antiparallel beta-barrel containing a ferric heme coordinated through His(57), similar to the structures of NP1 and NP4. All four Rhodnius nitrophorins transport NO and sequester histamine through heme binding, but only NP2 acts as an anticoagulant. Here, we demonstrate that recombinant NP2, but not recombinant NP1 or NP4, is a potent anticoagulant; recombinant NP3 also displays minor activity. Comparison of the nitrophorin structures suggests that a surface region near the C terminus and the loops between beta strands B-C and E-F is responsible for the anticoagulant activity. NP2 also displays larger NO association rates and smaller dissociation rates than NP1 and NP4, which may result from a more open and more hydrophobic distal pocket, allowing more rapid solvent reorganization on ligand binding. The NP2 protein core differs from NP1 and NP4 in that buried Glu(53), which allows for larger NO release rates when deprotonated, hydrogen bonds to invariant Tyr(81). Surprisingly, this tyrosine lies on the protein surface in NP1 and NP4.


    Organizational Affiliation

    Department of Biochemistry, University of Arizona, Tucson, Arizona 85721, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
NITROPHORIN 2
A
180Rhodnius prolixusN/A
Find proteins for Q26241 (Rhodnius prolixus)
Go to UniProtKB:  Q26241
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: 2 Å
  • R-Value Free: 0.246 
  • R-Value Work: 0.195 
  • Space Group: P 21 21 2
Unit Cell:
Length (Å)Angle (°)
a = 40.340α = 90.00
b = 127.960β = 90.00
c = 33.720γ = 90.00
Software Package:
Software NamePurpose
MADNESSdata collection
X-PLORmodel building
SCALAdata scaling
X-PLORphasing
MADNESSdata reduction
CNSrefinement
CCP4data scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2000-05-10
    Type: Initial release
  • Version 1.1: 2008-04-27
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2017-10-04
    Type: Refinement description