Biological Assembly 1  

 3D View: Structure | 1D-3D View | Electron Density | Validation Report | Ligand Interaction | Predict Membrane 

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Monomer - A1 

Biological assembly 1 assigned by authors.

Biological Assembly 2  

 3D View: Structure | 1D-3D View | Electron Density | Validation Report | Ligand Interaction | Predict Membrane 

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Monomer - A1 

Biological assembly 2 assigned by authors.

Macromolecule Content

• Total Structure Weight: 65.03 kDa 
• Atom Count: 4176 
• Modelled Residue Count: 499 
• Deposited Residue Count: 556 
• Unique protein chains: 1

1TLZ

Tsx structure complexed with uridine

• PDB DOI: 10.2210/pdb1TLZ/pdb

• Classification: MEMBRANE PROTEIN
• Organism(s): Escherichia coli
• Expression System: Escherichia coli
• Mutation(s): No 
• Membrane Protein: Yes  PDBTMMemProtMDmpstruc


• Deposited: 2004-06-10 Released: 2004-08-24 
• Deposition Author(s): Ye, J., van den Berg, B.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 3.10 Å
• R-Value Free: 0.299 
• R-Value Work: 0.276 
• R-Value Observed: 0.299 

Literature

Crystal structure of the bacterial nucleoside transporter Tsx.

Ye, J., Van Den Berg, B.

(2004) EMBO J 23: 3187-3195

• PubMed: 15272310 
• DOI: 10.1038/sj.emboj.7600330
• Primary Citation of Related Structures:  
  1TLW, 1TLY, 1TLZ


• PubMed Abstract: 
  

Tsx is a nucleoside-specific outer membrane (OM) transporter of Gram-negative bacteria. We present crystal structures of Escherichia coli Tsx in the absence and presence of nucleosides. These structures provide a mechanism for nucleoside transport across the bacterial OM. Tsx forms a monomeric, 12-stranded beta-barrel with a long and narrow channel spanning the outer membrane. The channel, which is shaped like a keyhole, contains several distinct nucleoside-binding sites, two of which are well defined. The base moiety of the nucleoside is located in the narrow part of the keyhole, while the sugar occupies the wider opening. Pairs of aromatic residues and flanking ionizable residues are involved in nucleoside binding. Nucleoside transport presumably occurs by diffusion from one binding site to the next.

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Organizational Affiliation: 

Department of Cell Biology, Howard Hughes Medical Institute and Harvard Medical School, Boston, MA 02115, USA.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Nucleoside-specific channel-forming protein tsx	A, B	278	Escherichia coli	Mutation(s): 0  Gene Names: tsx, nupA, b0411, Z0512, ECS0464, SF0348, S0356 Membrane Entity: Yes
UniProt
Find proteins for P0A927 (Escherichia coli (strain K12)) Explore P0A927  Go to UniProtKB:  P0A927

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
URI	C [auth A], D [auth B]	URIDINE C9 H12 N2 O6 DRTQHJPVMGBUCF-XVFCMESISA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 3.10 Å
• R-Value Free: 0.299 
• R-Value Work: 0.276 
• R-Value Observed: 0.299 
• Space Group: P 3₂ 2 1

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 149.861	α = 90
b = 149.861	β = 90
c = 120.849	γ = 120

Software Package:

Software Name	Purpose
CNS	refinement
DENZO	data reduction
SCALEPACK	data scaling
SOLVE	phasing

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2004-06-10 
• Released Date: 2004-08-24 
Deposition Author(s): Ye, J., van den Berg, B.

Revision History  

• Version 1.0: 2004-08-24
  Type: Initial release
  
• Version 1.1: 2008-04-30
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance