2WSW

Crystal Structure of Carnitine Transporter from Proteus mirabilis


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.29 Å
  • R-Value Free: 0.234 
  • R-Value Work: 0.209 
  • R-Value Observed: 0.210 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Structural Basis of Na(+)-Independent and Cooperative Substrate/Product Antiport in Cait.

Schulze, S.Koster, S.Geldmacher, U.Terwisscha Van Scheltinga, A.C.Kuhlbrandt, W.

(2010) Nature 467: 233

  • DOI: 10.1038/nature09310
  • Primary Citation of Related Structures:  
    2WSW, 2WSX

  • PubMed Abstract: 
  • Transport of solutes across biological membranes is performed by specialized secondary transport proteins in the lipid bilayer, and is essential for life. Here we report the structures of the sodium-independent carnitine/butyrobetaine antiporter CaiT from Proteus mirabilis (PmCaiT) at 2 ...

    Transport of solutes across biological membranes is performed by specialized secondary transport proteins in the lipid bilayer, and is essential for life. Here we report the structures of the sodium-independent carnitine/butyrobetaine antiporter CaiT from Proteus mirabilis (PmCaiT) at 2.3-A and from Escherichia coli (EcCaiT) at 3.5-A resolution. CaiT belongs to the family of betaine/carnitine/choline transporters (BCCT), which are mostly Na(+) or H(+) dependent, whereas EcCaiT is Na(+) and H(+) independent. The three-dimensional architecture of CaiT resembles that of the Na(+)-dependent transporters LeuT and BetP, but in CaiT a methionine sulphur takes the place of the Na(+) ion to coordinate the substrate in the central transport site, accounting for Na(+)-independent transport. Both CaiT structures show the fully open, inward-facing conformation, and thus complete the set of functional states that describe the alternating access mechanism. EcCaiT contains two bound butyrobetaine substrate molecules, one in the central transport site, the other in an extracellular binding pocket. In the structure of PmCaiT, a tryptophan side chain occupies the transport site, and access to the extracellular site is blocked. Binding of both substrates to CaiT reconstituted into proteoliposomes is cooperative, with Hill coefficients up to 1.7, indicating that the extracellular site is regulatory. We propose a mechanism whereby the occupied regulatory site increases the binding affinity of the transport site and initiates substrate translocation.


    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:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
BCCT FAMILY BETAINE/CARNITINE/CHOLINE TRANSPORTERA509Proteus mirabilisMutation(s): 0 
Find proteins for B4EY22 (Proteus mirabilis (strain HI4320))
Explore B4EY22 
Go to UniProtKB:  B4EY22
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CM5
Query on CM5

Download Ideal Coordinates CCD File 
C [auth A]5-CYCLOHEXYL-1-PENTYL-BETA-D-MALTOSIDE
C23 H42 O11
RVTGFZGNOSKUDA-ZNGNCRBCSA-N
 Ligand Interaction
1PE
Query on 1PE

Download Ideal Coordinates CCD File 
D [auth A]PENTAETHYLENE GLYCOL
C10 H22 O6
JLFNLZLINWHATN-UHFFFAOYSA-N
 Ligand Interaction
GOL
Query on GOL

Download Ideal Coordinates CCD File 
B [auth A]GLYCEROL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.29 Å
  • R-Value Free: 0.234 
  • R-Value Work: 0.209 
  • R-Value Observed: 0.210 
  • Space Group: H 3
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 129.198α = 90
b = 129.198β = 90
c = 160.264γ = 120
Software Package:
Software NamePurpose
PHENIXrefinement
XDSdata reduction
SCALAdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2010-09-08
    Type: Initial release
  • Version 1.1: 2011-05-08
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance