2R5O

Crystal structure of the C-terminal domain of wzt


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.3 Å
  • R-Value Free: 0.182 
  • R-Value Work: 0.166 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Substrate binding by a bacterial ABC transporter involved in polysaccharide export.

Cuthbertson, L.Kimber, M.S.Whitfield, C.

(2007) Proc.Natl.Acad.Sci.Usa 104: 19529-19534

  • DOI: 10.1073/pnas.0705709104

  • PubMed Abstract: 
  • ATP-binding-cassette (ABC) transporters are responsible for the export of a wide variety of cell-surface glycoconjugates in both Gram-positive and Gram-negative bacteria. These include the O-antigenic polysaccharide (O-PS) portion of lipopolysacchari ...

    ATP-binding-cassette (ABC) transporters are responsible for the export of a wide variety of cell-surface glycoconjugates in both Gram-positive and Gram-negative bacteria. These include the O-antigenic polysaccharide (O-PS) portion of lipopolysaccharide, a crucial virulence determinant in Gram-negative pathogens. O-PSs are synthesized by one of two fundamentally different pathways. Escherichia coli O serotypes O8 and O9a provide the prototype systems for studying O-PS export via ABC transporters. The transporter is composed of the transmembrane component Wzm and the nucleotide-binding component Wzt. Although the N-terminal domain of Wzt is a conventional ABC protein, the C-terminal domain of Wzt (C-Wzt) is a unique structural element that determines the specificity of the transporter for either the O8 or O9a O-PS. We show here that the two domains of Wzt can function when expressed as separate polypeptides; both are essential for export. In vitro, C-Wzt binds its cognate O-PS by recognizing a residue located at the nonreducing end of the polymer. The crystal structure of C-Wzt(O9a) is reported here and reveals a beta sandwich with an immunoglobulin-like topology that contains the O-PS-binding pocket. Substrate interactions with nucleotide-binding domains have been demonstrated in an ABC exporter previously. However, to our knowledge substrate binding by a discrete, cytoplasmic accessory domain in an extended nucleotide-binding domain polypeptide has not previously been demonstrated. Elucidation of the substrate-recognition system involved in O-PS export provides insight into the mechanism that coordinates polymer biosynthesis, termination, and export.


    Organizational Affiliation

    Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON, Canada.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Putative ATP binding component of ABC-transporter
A, B
188Escherichia coliMutation(s): 0 
Gene Names: ORF431
Find proteins for Q47591 (Escherichia coli)
Go to UniProtKB:  Q47591
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
NA
Query on NA

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A, B
SODIUM ION
Na
FKNQFGJONOIPTF-UHFFFAOYSA-N
 Ligand Interaction
CL
Query on CL

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Download CCD File 
A
CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
 Ligand Interaction
PG4
Query on PG4

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Download CCD File 
A
TETRAETHYLENE GLYCOL
C8 H18 O5
UWHCKJMYHZGTIT-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.3 Å
  • R-Value Free: 0.182 
  • R-Value Work: 0.166 
  • Space Group: P 42 21 2
Unit Cell:
Length (Å)Angle (°)
a = 106.081α = 90.00
b = 106.081β = 90.00
c = 70.351γ = 90.00
Software Package:
Software NamePurpose
DENZOdata reduction
SOLVEphasing
HKL-2000data collection
REFMACrefinement
SCALEPACKdata scaling
PDB_EXTRACTdata extraction
RESOLVEphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2007-12-25
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance
  • Version 1.2: 2017-10-25
    Type: Refinement description