4JC6

Mercury activation of the plant aquaporin SoPIP2;1 - structural and functional characterization


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.152 Å
  • R-Value Free: 0.227 
  • R-Value Work: 0.197 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Mercury increases water permeability of a plant aquaporin through a non-cysteine-related mechanism.

Frick, A.Jarva, M.Ekvall, M.Uzdavinys, P.Nyblom, M.Tornroth-Horsefield, S.

(2013) Biochem.J. 454: 491-499

  • DOI: 10.1042/BJ20130377

  • PubMed Abstract: 
  • Water transport across cellular membranes is mediated by a family of membrane proteins known as AQPs (aquaporins). AQPs were first discovered on the basis of their ability to be inhibited by mercurial compounds, an experiment which has followed the A ...

    Water transport across cellular membranes is mediated by a family of membrane proteins known as AQPs (aquaporins). AQPs were first discovered on the basis of their ability to be inhibited by mercurial compounds, an experiment which has followed the AQP field ever since. Although mercury inhibition is most common, many AQPs are mercury insensitive. In plants, regulation of AQPs is important in order to cope with environmental changes. Plant plasma membrane AQPs are known to be gated by phosphorylation, pH and Ca²⁺. We have previously solved the structure of the spinach AQP SoPIP2;1 (Spinacia oleracea plasma membrane intrinsic protein 2;1) in closed and open conformations and proposed a mechanism for how this gating can be achieved. To study the effect of mercury on SoPIP2;1 we solved the structure of the SoPIP2;1-mercury complex and characterized the water transport ability using proteoliposomes. The structure revealed mercury binding to three out of four cysteine residues. In contrast to what is normally seen for AQPs, mercury increased the water transport rate of SoPIP2;1, an effect which could not be attributed to any of the cysteine residues. This indicates that other factors might influence the effect of mercury on SoPIP2;1, one of which could be the properties of the lipid bilayer.


    Organizational Affiliation

    Department of Chemistry and Molecular Biology, University of Gothenburg, PO Box 462, SE-405 30 Gothenburg, Sweden.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Aquaporin
A, B, C, D, H, J, L, N
281Spinacia oleraceaMutation(s): 0 
Find proteins for Q41372 (Spinacia oleracea)
Go to UniProtKB:  Q41372
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
BOG
Query on BOG

Download SDF File 
Download CCD File 
A, C, D, H, J, L, N
B-OCTYLGLUCOSIDE
C14 H28 O6
HEGSGKPQLMEBJL-RKQHYHRCSA-N
 Ligand Interaction
HG
Query on HG

Download SDF File 
Download CCD File 
A, B, C, D, H, J, L, N
MERCURY (II) ION
Hg
BQPIGGFYSBELGY-UHFFFAOYSA-N
 Ligand Interaction
CD
Query on CD

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

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.152 Å
  • R-Value Free: 0.227 
  • R-Value Work: 0.197 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 123.546α = 90.00
b = 141.818β = 90.00
c = 186.515γ = 90.00
Software Package:
Software NamePurpose
PDB_EXTRACTdata extraction
SCALEPACKdata scaling
DENZOdata reduction
REFMACrefinement
MOLREPphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2013-09-11
    Type: Initial release
  • Version 1.1: 2015-02-04
    Type: Structure summary
  • Version 1.2: 2017-11-15
    Type: Refinement description