Jump into a New Fold—A Homology Based Model for the ABCG2/BCRP Multidrug Transporter
Fig 1
The general structural properties of the ABCG2 homology model.
The two monomers are colored by different light green colors. The most important parts, providing the interface between the TMD and NBD are the coupling helix (light blue) and the connecting helix (dark green). The functionally important R482 is colored ruby. The site of the most frequent polymorphism, Q141 is deep purple. The location of important mutations affecting biogenesis and function are labeled by dark green (R383) and orange (K86), respectively. Residues, which are probably significant in cholesterol modulation, are blue (Y413) and magenta (a.a. 555–558). Gray dots represent the boundaries of the hydrophobic region of the bilayer, defined by the OPM webserver. Insert: ABCG2 (green) and mouse ABCB1/Pgp (blue, PDBID: 4M1M) are overlaid. The mouse ABCB1 NBD is much further from the membrane bilayer and the distance between the NBDs of ABCB1 and ABCG2 (the Cα atoms of the Walker A Lys residues; K433 and K86, respectively) is 26 Å.