The cystic fibrosis transmembrane conductance regulator (CFTR) is a member of the ATP-
binding cassette (ABC) transporter superfamily. CFTR controls the flow of anions through the
apical membrane of epithelia. Dysfunctional CFTR causes the common lethal genetic
disease cystic fibrosis. Transitions between open and closed states of CFTR are regulated
by ATP binding and hydrolysis on the cytosolic nucleotide binding domains, which are
coupled with the transmembrane (TM) domains forming the pathway for anion permeation …