3PJZ

Crystal Structure of the Potassium Transporter TrkH from Vibrio parahaemolyticus


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.506 Å
  • R-Value Free: 0.299 
  • R-Value Work: 0.249 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Crystal structure of a potassium ion transporter, TrkH.

Cao, Y.Jin, X.Huang, H.Derebe, M.G.Levin, E.J.Kabaleeswaran, V.Pan, Y.Punta, M.Love, J.Weng, J.Quick, M.Ye, S.Kloss, B.Bruni, R.Martinez-Hackert, E.Hendrickson, W.A.Rost, B.Javitch, J.A.Rajashankar, K.R.Jiang, Y.Zhou, M.

(2011) Nature 471: 336-340

  • DOI: 10.1038/nature09731

  • PubMed Abstract: 
  • The TrkH/TrkG/KtrB proteins mediate K(+) uptake in bacteria and probably evolved from simple K(+) channels by multiple gene duplications or fusions. Here we present the crystal structure of a TrkH from Vibrio parahaemolyticus. TrkH is a homodimer, an ...

    The TrkH/TrkG/KtrB proteins mediate K(+) uptake in bacteria and probably evolved from simple K(+) channels by multiple gene duplications or fusions. Here we present the crystal structure of a TrkH from Vibrio parahaemolyticus. TrkH is a homodimer, and each protomer contains an ion permeation pathway. A selectivity filter, similar in architecture to those of K(+) channels but significantly shorter, is lined by backbone and side-chain oxygen atoms. Functional studies showed that TrkH is selective for permeation of K(+) and Rb(+) over smaller ions such as Na(+) or Li(+). Immediately intracellular to the selectivity filter are an intramembrane loop and an arginine residue, both highly conserved, which constrict the permeation pathway. Substituting the arginine with an alanine significantly increases the rate of K(+) flux. These results reveal the molecular basis of K(+) selectivity and suggest a novel gating mechanism for this large and important family of membrane transport proteins.


    Organizational Affiliation

    Department of Physiology & Cellular Biophysics, College of Physicians and Surgeons, Columbia University, 630 West 168th Street, New York, New York 10032, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Potassium uptake protein TrkH
A, B
494Vibrio parahaemolyticus serotype O3:K6 (strain RIMD 2210633)Mutation(s): 0 
Gene Names: trkH
Membrane protein
mpstruct
Group: 
TRANSMEMBRANE PROTEINS: ALPHA-HELICAL
Sub Group: 
Superfamily of K+ Transporters (SKT proteins)
Protein: 
TrkH potassium ion transporter
Find proteins for Q87TN7 (Vibrio parahaemolyticus serotype O3:K6 (strain RIMD 2210633))
Go to UniProtKB:  Q87TN7
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
K
Query on K

Download SDF File 
Download CCD File 
A, B
POTASSIUM ION
K
NPYPAHLBTDXSSS-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.506 Å
  • R-Value Free: 0.299 
  • R-Value Work: 0.249 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 91.489α = 90.00
b = 97.406β = 90.00
c = 195.653γ = 90.00
Software Package:
Software NamePurpose
ADSCdata collection
PDB_EXTRACTdata extraction
DENZOdata reduction
DMphasing
SCALEPACKdata scaling
PHENIXrefinement
PHENIXphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2011-01-19
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance
  • Version 1.2: 2017-11-08
    Type: Refinement description