In vitro reassembly of the ribose ATP-binding cassette transporter reveals a distinct set of transport complexes.

Bacterial ATP-binding cassette (ABC) importers are primary active transporters that are critical for nutrient uptake. Based on structural and functional studies, ABC importers can be divided into two distinct classes, type I and type II. Type I importers follow a strict alternating access mechanism that is driven by the presence of the substrate.

Topology of RbsC, the membrane component of the Escherichia coli ribose transporter.

The topology of RbsC, the membrane component of the ribose transporter in Escherichia coli, has been determined by using 34 single-cysteine mutants and a modified fluorescence labeling technique designated multiplex labeling. This technique gives topology, expression, and localization information for a membrane protein from a single batch of bacterial cells. The results indicate that RbsC contains 10 transmembrane-spanning helices, with the N and C termini being in the cytosol.