4OH3

Crystal structure of a nitrate transporter


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.25 Å
  • R-Value Free: 0.307 
  • R-Value Work: 0.235 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Crystal structure of the plant dual-affinity nitrate transporter NRT1.1.

Sun, J.Bankston, J.R.Payandeh, J.Hinds, T.R.Zagotta, W.N.Zheng, N.

(2014) Nature 507: 73-77

  • DOI: 10.1038/nature13074

  • PubMed Abstract: 
  • Nitrate is a primary nutrient for plant growth, but its levels in soil can fluctuate by several orders of magnitude. Previous studies have identified Arabidopsis NRT1.1 as a dual-affinity nitrate transporter that can take up nitrate over a wide range ...

    Nitrate is a primary nutrient for plant growth, but its levels in soil can fluctuate by several orders of magnitude. Previous studies have identified Arabidopsis NRT1.1 as a dual-affinity nitrate transporter that can take up nitrate over a wide range of concentrations. The mode of action of NRT1.1 is controlled by phosphorylation of a key residue, Thr 101; however, how this post-translational modification switches the transporter between two affinity states remains unclear. Here we report the crystal structure of unphosphorylated NRT1.1, which reveals an unexpected homodimer in the inward-facing conformation. In this low-affinity state, the Thr 101 phosphorylation site is embedded in a pocket immediately adjacent to the dimer interface, linking the phosphorylation status of the transporter to its oligomeric state. Using a cell-based fluorescence resonance energy transfer assay, we show that functional NRT1.1 dimerizes in the cell membrane and that the phosphomimetic mutation of Thr 101 converts the protein into a monophasic high-affinity transporter by structurally decoupling the dimer. Together with analyses of the substrate transport tunnel, our results establish a phosphorylation-controlled dimerization switch that allows NRT1.1 to uptake nitrate with two distinct affinity modes.


    Organizational Affiliation

    Department of Pharmacology, Box 357280, University of Washington, Seattle, Washington 98195, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Nitrate transporter 1.1
A, B
599Arabidopsis thalianaMutation(s): 0 
Gene Names: NPF6.3 (CHL1, NRT1, NRT1.1)
Membrane protein
mpstruct
Group: 
TRANSMEMBRANE PROTEINS: ALPHA-HELICAL
Sub Group: 
Major Facilitator Superfamily (MFS) Transporters
Protein: 
NRT1.1 nitrate transporter, apo form
Find proteins for Q05085 (Arabidopsis thaliana)
Go to UniProtKB:  Q05085
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
LMT
Query on LMT

Download SDF File 
Download CCD File 
A, B
DODECYL-BETA-D-MALTOSIDE
C24 H46 O11
NLEBIOOXCVAHBD-QKMCSOCLSA-N
 Ligand Interaction
NO3
Query on NO3

Download SDF File 
Download CCD File 
A, B
NITRATE ION
N O3
NHNBFGGVMKEFGY-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.25 Å
  • R-Value Free: 0.307 
  • R-Value Work: 0.235 
  • Space Group: C 2 2 21
Unit Cell:
Length (Å)Angle (°)
a = 84.800α = 90.00
b = 188.465β = 90.00
c = 262.848γ = 90.00
Software Package:
Software NamePurpose
HKL-2000data reduction
HKL-2000data scaling
PHENIXrefinement
PHENIXphasing
ADSCdata collection
PHENIXmodel building

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2014-03-05
    Type: Initial release
  • Version 1.1: 2014-03-12
    Type: Database references