A complex for the transport of metabolites out of the cell, consisting of 4 domains: two ATP-binding domains and two membrane spanning domains. In some cases, all 4 domains are contained on 1 polypeptide, while in others one ATP-binding domain and one membrane spanning domain are together on one polypeptide in what is called a half transporter. Two half-transporters come together to form a functional transporter. Transport of the substrate across the membrane is driven by the hydrolysis of ATP.
ATP-binding cassette (ABC) transporter complex, integrated substrate binding