Domain Organization of Bile Salt Transporter (BSEP)

1. Domain Organization of Bile Salt Transporter (BSEP) SIGMA-ALDRICH

2. Domain Organization of Bile Salt Transporter (BSEP) BSEP is a member of the MDR/TAP subfamily of Multidrug ABC transporters. Transporters of this subfamily have the general form of TMD-ABC2 , TMD, transmembrane domain; ABC, and ATP-binding cassette, although they are half transporters. The TMDs are composed of six helixes buried in the lipid bilayer of plasma membrane and the ATP binding ABCs are exposed in the cytosol. The TMD helixes are envisioned to form channels spanning the plasma membrane. There is experimental evidence for multiple substrate binding sites associated with the TMDs. Half transporters form tight functional coupling in multimolecular complexes. References Meier, P.J., and Steiger, B., Bile salt transporters. Annu. Rev. Physiol., 64, 635-661 (2001). Klein, I., et al., An inventory of human ABC proteins. Biochim. Biophys. Acta., 1461 237-262 (1999).