The xyz of ABC Transporters

Cells produce a variety of ABC transporter proteins that shuttle numerous molecules across the plasma membrane so as to maintain the integrity of the intracellular milieu. As Higgins and Linton discuss in their Perspective, the first high-resolution crystal structure of one of these intricate ABC transporters has now been obtained (Chang and Roth). As the Perspective authors note, although the structure confirms much of the existing biochemical evidence, it also yields some interesting surprises that it will take much more analysis to explain.