6ST1

Taurine ABC transporter substrate binding protein TauA from E. coli in complex with 2-(N-Morpholino)ethanesulfonic acid (MES)


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.55 Å
  • R-Value Free: 0.231 
  • R-Value Work: 0.193 

Starting Model: experimental
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wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Desolvation of the substrate-binding protein TauA dictates ligand specificity for the alkanesulfonate ABC importer TauABC.

Qu, F.ElOmari, K.Wagner, A.De Simone, A.Beis, K.

(2019) Biochem J 476: 3649-3660

  • DOI: https://doi.org/10.1042/BCJ20190779
  • Primary Citation of Related Structures:  
    6SSY, 6ST0, 6ST1, 6STL

  • PubMed Abstract: 

    Under limiting sulfur availability, bacteria can assimilate sulfur from alkanesulfonates. Bacteria utilize ATP-binding cassette (ABC) transporters to internalise them for further processing to release sulfur. In gram-negative bacteria the TauABC and SsuABC ensure internalization, although, these two systems have common substrates, the former has been characterized as a taurine specific system. TauA and SsuA are substrate-binding proteins (SBPs) that bind and bring the alkanesulfonates to the ABC importer for transport. Here, we have determined the crystal structure of TauA and have characterized its thermodynamic binding parameters by isothermal titration calorimetry in complex with taurine and different alkanesulfonates. Our structures revealed that the coordination of the alkanesulfonates is conserved, with the exception of Asp205 that is absent from SsuA, but the thermodynamic parameters revealed a very high enthalpic penalty cost for binding of the other alkanesulfonates relative to taurine. Our molecular dynamic simulations indicated that the different levels of hydration of the binding site contributed to the selectivity for taurine over the other alkanesulfonates. Such selectivity mechanism is very likely to be employed by other SBPs of ABC transporters.


  • Organizational Affiliation

    Department of Life Sciences, Imperial College London, South Kensington, London SW7 2AZ, U.K.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Taurine-binding periplasmic protein
A, B
298Escherichia coli K-12Mutation(s): 0 
Gene Names: tauAssiAyaiRb0365JW0357
UniProt
Find proteins for Q47537 (Escherichia coli (strain K12))
Explore Q47537 
Go to UniProtKB:  Q47537
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ47537
Sequence Annotations
Expand
  • Reference Sequence
Small Molecules
Ligands 3 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
MES
Query on MES

Download Ideal Coordinates CCD File 
C [auth A],
L [auth B]
2-(N-MORPHOLINO)-ETHANESULFONIC ACID
C6 H13 N O4 S
SXGZJKUKBWWHRA-UHFFFAOYSA-N
IOD
Query on IOD

Download Ideal Coordinates CCD File 
D [auth A]
E [auth A]
F [auth A]
G [auth A]
H [auth A]
D [auth A],
E [auth A],
F [auth A],
G [auth A],
H [auth A],
I [auth A],
J [auth A],
K [auth A],
M [auth B],
N [auth B],
O [auth B],
P [auth B],
Q [auth B],
R [auth B]
IODIDE ION
I
XMBWDFGMSWQBCA-UHFFFAOYSA-M
GOL
Query on GOL

Download Ideal Coordinates CCD File 
S [auth B],
T [auth B]
GLYCEROL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.55 Å
  • R-Value Free: 0.231 
  • R-Value Work: 0.193 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 45.22α = 90
b = 73.02β = 90
c = 163.9γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
xia2data reduction
Aimlessdata scaling
PHASERphasing

Structure Validation

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Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
Medical Research Council (United Kingdom)United KingdomMR/N020103/1

Revision History  (Full details and data files)

  • Version 1.0: 2019-12-18
    Type: Initial release
  • Version 1.1: 2024-01-24
    Changes: Data collection, Database references, Refinement description