CAR is a transmembrane bound protein with two Ig-like extracellular domains, a transmembrane domain, a cytoplasmic domain, and two N-linked glycosylation sites. CAR contains two disulfide bonded loops (residues 35-130 and 155-220). The N-terminal segment comprises the two extracellular domains (D1 and D2). D1 is most distal from the membrane and contains a V/Ig-like fold whereas D2 is more proximal. The cytoplasmic tail of CAR contains the amino acids G S I V, which is characterized as a class 1 PDZ-binding motif for interacting with proteins containing PDZ domains.
