| ABC (ATP binding cassette) transporters catalyze the transport of a wide variety of molecules across lipid bilayers into or out of cells and organelles. They form one of the largest known protein families and are found in organisms from all kingdoms of life. The basic architecture of ABC transporters1,2 is shown in the figure. One of the ABC transporters that is studied in detail is the osmoregulatory ABC transporter OpuA (class D). Osmotic control of OpuA involves gating by intracellular ionic strength and is mediated by lipid-protein interactions.3 The tandem CBS domain4, which is linked to the nucleotide binding protein, plays a pivotal role in the regulation. A structural genomics approach is used to determine to the structures of proteins belonging to other classes of ABC transporters. |
