1NP4

CRYSTAL STRUCTURE OF NITROPHORIN 4 FROM RHODNIUS PROLIXUS

• PDB DOI: https://doi.org/10.2210/pdb1NP4/pdb

• Classification: TRANSPORT PROTEIN
• Organism(s): Rhodnius prolixus
• Expression System: Escherichia coli BL21(DE3)
• Mutation(s): No 


• Deposited: 1998-07-29 Released: 1998-08-05 
• Deposition Author(s): Andersen, J.F., Weichsel, A., Champagne, D.E., Balfour, C.A., Montfort, W.R.

---

Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 1.50 Å
• R-Value Free: 0.262 
• R-Value Work: 0.204 
• R-Value Observed: 0.204 

Literature

The crystal structure of nitrophorin 4 at 1.5 A resolution: transport of nitric oxide by a lipocalin-based heme protein.

Andersen, J.F., Weichsel, A., Balfour, C.A., Champagne, D.E., Montfort, W.R.

(1998) Structure 6: 1315-1327

• PubMed: 9782054 
• DOI: https://doi.org/10.1016/s0969-2126(98)00131-2
• Primary Citation of Related Structures:  
  1NP4


• PubMed Abstract: 
  

  Nitrophorins are nitric oxide (NO) transport proteins from the saliva of blood-feeding insects, which act as vasodilators and anti-platelet agents. Rhodnius prolixus, an insect that carries the trypanosome that causes Chagas' disease, releases four NO-loaded nitrophorins during blood feeding, whereupon the ligand is released into the bloodstream or surrounding tissue of the host. Histamine, a signaling molecule released by the host upon tissue damage, is tightly bound by the nitrophorins; this may facilitate the release of NO and reduce inflammation in the host.

---

Organizational Affiliation: 

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

Biological Assembly 1  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Monomer - A1 

Biological assembly 1 assigned by authors.

Macromolecule Content

• Total Structure Weight: 20.93 kDa 
• Atom Count: 1,548 
• Modelled Residue Count: 184 
• Deposited Residue Count: 184 
• Unique protein chains: 1

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
PROTEIN (NITROPHORIN 4)	A	184	Rhodnius prolixus	Mutation(s): 0
UniProt
Find proteins for Q94734 (Rhodnius prolixus) Explore Q94734  Go to UniProtKB:  Q94734

Small Molecules

Ligands 2 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
HEM	B [auth A]	PROTOPORPHYRIN IX CONTAINING FE C34 H32 Fe N4 O4 KABFMIBPWCXCRK-RGGAHWMASA-L
NH3	C [auth A]	AMMONIA H3 N QGZKDVFQNNGYKY-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 1.50 Å
• R-Value Free: 0.262 
• R-Value Work: 0.204 
• R-Value Observed: 0.204 
• Space Group: C 1 2 1

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 70.54	α = 90
b = 43.65	β = 94.19
c = 53.12	γ = 90

Software Package:

Software Name	Purpose
MADNESS	data collection
ROTAVATA	data reduction
CCP4	model building
X-PLOR	refinement
MADNESS	data reduction
CCP4	data scaling
ROTAVATA	data scaling
CCP4	phasing

Structure Validation

Entry History 

Deposition Data

• Released Date: 1998-08-05 
Deposition Author(s): Andersen, J.F., Weichsel, A., Champagne, D.E., Balfour, C.A., Montfort, W.R.

Revision History  

• Version 1.0: 1998-08-05
  Type: Initial release
  
• Version 1.1: 2008-04-27
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance
• Version 1.3: 2017-10-04
  Changes: Refinement description
• Version 1.4: 2023-08-16
  Changes: Data collection, Database references, Derived calculations, Refinement description