ATP-binding cassette transporter GrfA (GrfA)

ATP-binding cassette (ABC) transporters are a large superfamily of integral membrane proteins that utilize the energy from ATP binding and hydrolysis to transport a wide variety of substrates across cellular membranes. The GrfA protein is presumed to be a member of this family, consisting of two transmembrane domains (TMDs) and two nucleotide-binding domains (NBDs). Substrate binds to high-affinity sites on TMDs, inducing conformational changes in NBDs, enhancing their affinity for ATP. Binding of two molecules of ATP causes dimerization of NBDs, leading to further conformational changes that open the TMD chamber toward the opposite side of the membrane. Substrate is released; subsequent hydrolysis of ATP returns transporter to its original state. ABC transporters can function as importers or exporters. Its physiological role would depend on its substrate specificity.

Substrate translocation via ATP hydrolysis-driven conformational changes