Substrate-Induced Conformational Changes in the S-Component ThiT from an Energy Coupling Factor TransporterMajsnerowska, M., Hänelt, I., Wunnicke, D., Schaefer, L. V., Steinhoff, H-J. & Slotboom, D. J., 7-May-2013, In : Structure. 21, 5, p. 861-867 7 p.
Research output: Contribution to journal › Article › Academic › peer-review
Energy coupling factor (ECF) transporters are a recently discovered class of ABC transporters that mediate vitamin uptake in prokaryotes. Characteristic for ECF-type ABC transporters are small integral membrane proteins (S-components) that bind the transported substrates with high affinity. S-components associate with a second membrane protein (EcfT) and two peripheral ATPases to form a complete ATP-dependent transporter. Here, we have used EPR spectroscopy, stopped-flow fluorescence spectroscopy, and molecular dynamics simulations to determine the structural rearrangements that take place in the S-component ThiT from Lactococcus lactis upon binding of thiamin. Thiamin-induced conformational changes were confined to the long and partially membrane-embedded loop between transmembrane helices 1 and 2 that acts as a lid to occlude the binding site. The results indicate that solitary ThiT functions as a bona fide high-affinity substrate binding protein, which lacks a translocation pathway within the protein.
|Number of pages||7|
|Publication status||Published - 7-May-2013|
- MOLECULAR-DYNAMICS SIMULATIONS, LINEAR CONSTRAINT SOLVER, AMBER FORCE-FIELD, LACTOCOCCUS-LACTIS, ABC TRANSPORTERS, EPR SPECTROSCOPY, BINDING, PROTEINS, PARAMETERS, SYSTEMS