Most eukaryotic ABC transporters are involved in exporting small molecules from the cytosol. In this subset of the ABC transporters, does the small molecule bind better to the ATP-bound (B) or the ATP-free (F) transporter? Write down your answer as B or
F. Hint: The ATP-bound transporter "faces outward."

Question

Quizplus · Accepted Answer

In most eukaryotic ABC transporters, the substrate binds to the inward-facing ATP-free state of the transporter, which then binds ATP to face outward and release the substrate. Thus, most eukaryotic ABC transporters function as exporters.

Most Eukaryotic ABC Transporters Are Involved in Exporting Small Molecules