Substrate bound S-component of folate ECF transporter

Experimental Data Snapshot

  • Resolution: 3.01 Å
  • R-Value Free: 0.286 
  • R-Value Work: 0.235 
  • R-Value Observed: 0.238 

Starting Model: experimental
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This is version 1.2 of the entry. See complete history


Structural insight in the toppling mechanism of an energy-coupling factor transporter.

Swier, L.J.Guskov, A.Slotboom, D.J.

(2016) Nat Commun 7: 11072-11072

  • DOI: https://doi.org/10.1038/ncomms11072
  • Primary Citation of Related Structures:  
    5D0Y, 5D3M, 5JSZ

  • PubMed Abstract: 

    Energy-coupling factor (ECF) transporters mediate uptake of micronutrients in prokaryotes. The transporters consist of an S-component that binds the transported substrate and an ECF module (EcfAA'T) that binds and hydrolyses ATP. The mechanism of transport is poorly understood but presumably involves an unusual step in which the membrane-embedded S-component topples over to carry the substrate across the membrane. In many ECF transporters, the S-component dissociates from the ECF module after transport. Subsequently, substrate-bound S-components out-compete the empty proteins for re-binding to the ECF module in a new round of transport. Here we present crystal structures of the folate-specific transporter ECF-FolT from Lactobacillus delbrueckii. Interaction of the ECF module with FolT stabilizes the toppled state, and simultaneously destroys the high-affinity folate-binding site, allowing substrate release into the cytosol. We hypothesize that differences in the kinetics of toppling can explain how substrate-loaded FolT out-competes apo-FolT for association with the ECF module.

  • Organizational Affiliation

    Groningen Biomolecular Science and Biotechnology Institute, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Conserved hypothetical membrane protein
A, B
184Lactobacillus delbrueckii subsp. bulgaricusMutation(s): 0 
Gene Names: LBVIB27_08730LBVIB44_08025
Membrane Entity: Yes 
Find proteins for Q1G930 (Lactobacillus delbrueckii subsp. bulgaricus (strain ATCC 11842 / DSM 20081 / BCRC 10696 / JCM 1002 / NBRC 13953 / NCIMB 11778 / NCTC 12712 / WDCM 00102 / Lb 14))
Explore Q1G930 
Go to UniProtKB:  Q1G930
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ1G930
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 3.01 Å
  • R-Value Free: 0.286 
  • R-Value Work: 0.235 
  • R-Value Observed: 0.238 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 108.91α = 90
b = 77.54β = 116.36
c = 89.45γ = 90
Software Package:
Software NamePurpose
XDSdata reduction
XSCALEdata scaling

Structure Validation

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Ligand Structure Quality Assessment 

Entry History & Funding Information

Deposition Data

Funding OrganizationLocationGrant Number
European Research Council282083

Revision History  (Full details and data files)

  • Version 1.0: 2016-04-06
    Type: Initial release
  • Version 1.1: 2016-04-13
    Changes: Database references
  • Version 1.2: 2024-01-10
    Changes: Author supporting evidence, Data collection, Database references, Refinement description