2VPN

High-resolution structure of the periplasmic ectoine-binding protein from TeaABC TRAP-transporter of Halomonas elongata


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.55 Å
  • R-Value Free: 0.204 
  • R-Value Work: 0.158 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

1.55 A Structure of the Ectoine Binding Protein Teaa of the Osmoregulated Trap-Transporter Teaabc from Halomonas Elongata.

Kuhlmann, S.I.Terwisscha Van Scheltinga, A.C.Bienert, R.Kunte, H.J.Ziegler, C.

(2008) Biochemistry 47: 9475

  • DOI: 10.1021/bi8006719
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • TeaABC from the moderate halophilic bacterium Halomonas elongata belongs to the tripartite ATP-independent periplasmic transporters (TRAP-T), a family of secondary transporters functioning in conjunction with periplasmic substrate binding proteins. T ...

    TeaABC from the moderate halophilic bacterium Halomonas elongata belongs to the tripartite ATP-independent periplasmic transporters (TRAP-T), a family of secondary transporters functioning in conjunction with periplasmic substrate binding proteins. TeaABC facilitates the uptake of the compatible solutes ectoine and hydroxyectoine that are accumulated in the cytoplasm under hyperosmotic stress to protect the cell from dehydration. TeaABC is the only known TRAP-T activated by osmotic stress. Currently, our knowledge on the osmoregulated compatible solute transporter is limited to ABC transporters or conventional secondary transporters. Therefore, this study presents the first detailed analysis of the molecular mechanisms underlying substrate recognition of the substrate binding protein of an osmoregulated TRAP-T. In the present study we were able to demonstrate by isothermal titration calorimetry measurements that TeaA is a high-affinity ectoine binding protein ( K d = 0.19 microM) that also has a significant but somewhat lower affinity to hydroxyectoine ( K d = 3.8 microM). Furthermore, we present the structure of TeaA in complex with ectoine at a resolution of 1.55 A and hydroxyectoine at a resolution of 1.80 A. Analysis of the TeaA binding pocket and comparison of its structure to other compatible solute binding proteins from ABC transporters reveal common principles in compatible solute binding but also significant differences like the solvent-mediated specific binding of ectoine to TeaA.


    Organizational Affiliation

    Department of Structural Biology, Max-Planck-Institute of Biophysics, Max-von-Laue-Strasse 3, 60438 Frankfurt am Main, Germany.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
PERIPLASMIC SUBSTRATE BINDING PROTEIN
A, B
316Halomonas elongata (strain ATCC 33173 / DSM 2581 / NBRC 15536 / NCIMB 2198 / 1H9)Mutation(s): 0 
Gene Names: teaA
Find proteins for E1VBK1 (Halomonas elongata (strain ATCC 33173 / DSM 2581 / NBRC 15536 / NCIMB 2198 / 1H9))
Go to UniProtKB:  E1VBK1
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
4CS
Query on 4CS

Download SDF File 
Download CCD File 
A, B
(4S)-2-METHYL-1,4,5,6-TETRAHYDROPYRIMIDINE-4-CARBOXYLIC ACID
ECTOINE
C6 H10 N2 O2
WQXNXVUDBPYKBA-YFKPBYRVSA-N
 Ligand Interaction
MG
Query on MG

Download SDF File 
Download CCD File 
A, B
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
4CSKd: 190 nM BINDINGMOAD
4CSKd: 190 nM PDBBIND
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.55 Å
  • R-Value Free: 0.204 
  • R-Value Work: 0.158 
  • Space Group: P 1
Unit Cell:
Length (Å)Angle (°)
a = 48.300α = 80.80
b = 52.200β = 85.80
c = 63.500γ = 77.90
Software Package:
Software NamePurpose
autoSHARPphasing
REFMACrefinement
XSCALEdata scaling
XDSdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2008-08-26
    Type: Initial release
  • Version 1.1: 2011-05-08
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance