ABC Drug-Transporters

Synonyms

ABC (ATP-binding cassette) superfamily; ABC transporter

Definition

The adenosine triphosphate (ATP)-binding cassette (ABC) transporters form the largest family of transmembrane proteins that use ATP-derived energy to transport various substances over cell membranes. Primary-active transporters, driven by energy released from ATP by inherent ATPase activity, that export substrates from the cell against a chemical gradient. Based on the arrangement of the nucleotide-binding domain and the topology of its transmembrane domains, human ABC transporters are classified into seven distinct families (ABC-A to ABC-G), including ABCB1 (P-glycoprotein), ABCC1 (MRP1), ABCC2 (cMOAT, MRP2), ABCC4 (MRP4), and ABCG2 (ABCP, MXR, BCRP). Structural characteristics based on their Walker motif (ATP-binding domain) and their nucleotide-binding folds across the membrane are responsible for their classification into this superfamily. Their localization pattern over the body suggests that they have an...