Identification of putative steroid-binding sites in human ABCB1 and ABCG2.
Homology modelling was used to generate three-dimensional structures of the nucleotide-binding domains (NBDs) of human ABCB1 and ABCG2. Interactions between a series of steroidal ligands and transporter NBDs were investigated using an in silico docking approach. C-terminal ABCB1 NBD (ABCB1 NBD2) was predicted to bind steroids within a cavity formed partly by the P-Loop, Tyr1044 and Ile1050. The P-Loop within ABCG2 NBD was also predicted to be involved in steroid binding. No overlap between ATP- and RU-486-binding sites was predicted in either NBD, though overlaps between ATP- and steroid-binding sites were predicted in the vicinity of the P-Loop in both nucleotide-binding domains.
Mares-Sámano
Sergio
S
University of Manchester, School of Pharmacy & Pharmaceutical Sciences, Stopford Building, Oxford Road, Manchester M13 9PT, UK.
Badhan
Raj
R
Penny
Jeffrey
J
D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000737:chemistry* / Q000378:metabolism*; D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters / Q000737:chemistry* / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000378:metabolism; D000595:Amino Acid Sequence; D001665:Binding Sites; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000737:chemistry* / Q000378:metabolism*; D011485:Protein Binding; D011487:Protein Conformation; D016415:Sequence Alignment; D013256:Steroids / Q000737:chemistry / Q000378:metabolism*; D040681:Structural Homology, Protein
C513055:ABCB1 protein, human; C116614:ABCG2 protein, human; D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters; D009363:Neoplasm Proteins; D013256:Steroids; D000255:Adenosine Triphosphate