Structure of the multidrug resistance P-glycoprotein

In order to elucidate the mechanism by which the multidrug resistance P-glycoprotein extrudes cytotoxic drugs from the cell, and particularly the number and nature of the drug binding site(s), knowledge of the structure of P-gp is essential. A considerable body of genetic and biochemical data has accrued which gives insights into P-gp structure and function. These data are critically reviewed, particularly in relation to the low resolution structure of P-gp which has recently been determined by electron microscopy. P-gp is one of the best characterised of the ABC transporters and these structure-function studies may have more general implications.