6zg3
the structure of ECF PanT transporter in a complex with a nanobodythe structure of ECF PanT transporter in a complex with a nanobody
Structural highlights
FunctionECFA1_LACDA ATP-binding (A) component of a common energy-coupling factor (ECF) ABC-transporter complex. Unlike classic ABC transporters this ECF transporter provides the energy necessary to transport a number of different substrates. Publication Abstract from PubMedEnergy-coupling factor (ECF) transporters mediate import of micronutrients in prokaryotes. They consist of an integral membrane S-component (that binds substrate) and ECF module (that powers transport by ATP hydrolysis). It has been proposed that different S-components compete for docking onto the same ECF module, but a minimal liposome-reconstituted system, required to substantiate this idea, is lacking. Here, we co-reconstituted ECF transporters for folate (ECF-FolT2) and pantothenate (ECF-PanT) into proteoliposomes, and assayed for crosstalk during active transport. The kinetics of transport showed that exchange of S-components is part of the transport mechanism. Competition experiments suggest much slower substrate association with FolT2 than with PanT. Comparison of a crystal structure of ECF-PanT with previously determined structures of ECF-FolT2 revealed larger conformational changes upon binding of folate than pantothenate, which could explain the kinetic differences. Our work shows that a minimal in vitro system with two reconstituted transporters recapitulates intricate kinetics behaviour observed in vivo. In vitro reconstitution of dynamically interacting integral membrane subunits of energy-coupling factor transporters.,Setyawati I, Stanek WK, Majsnerowska M, Swier LJYM, Pardon E, Steyaert J, Guskov A, Slotboom DJ Elife. 2020 Dec 22;9:e64389. doi: 10.7554/eLife.64389. PMID:33350937[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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