ABC transporter architecture and mechanism: implications from the crystal structures of BtuCD and BtuF.

ABC transporters are ubiquitous membrane proteins that facilitate unidirectional substrate translocation across the lipid bilayer. Over the past five years, new crystal structures have advanced our understanding of how ABC transporters couple adenosine triphosphate (ATP) hydrolysis to substrate transport. In the following, we will briefly review the results of these structural investigations and outline their mechanistic implications.