Insights into the bilayer-mediated toppling mechanism of a folate-specific ECF transporter by cryo-EM

Chancievan Thangaratnarajah, Jan Rheinberger, Cristina Paulino*, Dirk J Slotboom*

*Bijbehorende auteur voor dit werk

OnderzoeksoutputAcademicpeer review

8 Citaten (Scopus)
163 Downloads (Pure)


Energy-coupling factor (ECF)-type transporters are small, asymmetric membrane protein complexes (∼115 kDa) that consist of a membrane-embedded, substrate-binding protein (S component) and a tripartite ATP-hydrolyzing module (ECF module). They import micronutrients into bacterial cells and have been proposed to use a highly unusual transport mechanism, in which the substrate is dragged across the membrane by a toppling motion of the S component. However, it remains unclear how the lipid bilayer could accommodate such a movement. Here, we used cryogenic electron microscopy at 200 kV to determine structures of a folate-specific ECF transporter in lipid nanodiscs and detergent micelles at 2.7- and 3.4-Å resolution, respectively. The structures reveal an irregularly shaped bilayer environment around the membrane-embedded complex and suggest that toppling of the S component is facilitated by protein-induced membrane deformations. In this way, structural remodeling of the lipid bilayer environment is exploited to guide the transport process.

Originele taal-2English
Aantal pagina's9
TijdschriftProceedings of the National Academy of Sciences of the United States of America
Nummer van het tijdschrift34
StatusPublished - 24-aug.-2021

Citeer dit