4NEF

X-ray structure of human Aquaporin 2


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.75 Å
  • R-Value Free: 0.225 
  • R-Value Work: 0.202 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

X-ray structure of human aquaporin 2 and its implications for nephrogenic diabetes insipidus and trafficking

Frick, A.Eriksson, U.K.de Mattia, F.Oberg, F.Hedfalk, K.Neutze, R.de Grip, W.J.Deen, P.M.Tornroth-Horsefield, S.

(2014) Proc.Natl.Acad.Sci.USA 111: 6305-6310

  • DOI: 10.1073/pnas.1321406111

  • PubMed Abstract: 
  • Human aquaporin 2 (AQP2) is a water channel found in the kidney collecting duct, where it plays a key role in concentrating urine. Water reabsorption is regulated by AQP2 trafficking between intracellular storage vesicles and the apical membrane. Thi ...

    Human aquaporin 2 (AQP2) is a water channel found in the kidney collecting duct, where it plays a key role in concentrating urine. Water reabsorption is regulated by AQP2 trafficking between intracellular storage vesicles and the apical membrane. This process is tightly controlled by the pituitary hormone arginine vasopressin and defective trafficking results in nephrogenic diabetes insipidus (NDI). Here we present the X-ray structure of human AQP2 at 2.75 Å resolution. The C terminus of AQP2 displays multiple conformations with the C-terminal α-helix of one protomer interacting with the cytoplasmic surface of a symmetry-related AQP2 molecule, suggesting potential protein-protein interactions involved in cellular sorting of AQP2. Two Cd(2+)-ion binding sites are observed within the AQP2 tetramer, inducing a rearrangement of loop D, which facilitates this interaction. The locations of several NDI-causing mutations can be observed in the AQP2 structure, primarily situated within transmembrane domains and the majority of which cause misfolding and ER retention. These observations provide a framework for understanding why mutations in AQP2 cause NDI as well as structural insights into AQP2 interactions that may govern its trafficking.


    Organizational Affiliation

    Department of Chemistry and Molecular Biology, University of Gothenburg, 405 30 Gothenburg, Sweden.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Aquaporin-2
A, B, C, D
242Homo sapiensMutation(s): 0 
Gene Names: AQP2
Membrane protein
mpstruct
Group: 
TRANSMEMBRANE PROTEINS: ALPHA-HELICAL
Sub Group: 
Channels: Aquaporins and Glyceroporins
Protein: 
AQP2 Aquaporin from kidney
Find proteins for P41181 (Homo sapiens)
Go to Gene View: AQP2
Go to UniProtKB:  P41181
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ZN
Query on ZN

Download SDF File 
Download CCD File 
A
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
 Ligand Interaction
CD
Query on CD

Download SDF File 
Download CCD File 
A, D
CADMIUM ION
Cd
WLZRMCYVCSSEQC-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.75 Å
  • R-Value Free: 0.225 
  • R-Value Work: 0.202 
  • Space Group: P 42
Unit Cell:
Length (Å)Angle (°)
a = 119.110α = 90.00
b = 119.110β = 90.00
c = 90.621γ = 90.00
Software Package:
Software NamePurpose
PDB_EXTRACTdata extraction
PHASERphasing
MOSFLMdata reduction
SCALAdata scaling
BUSTERrefinement
BUSTER-TNTrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2014-04-16
    Type: Initial release
  • Version 1.1: 2014-12-10
    Type: Database references