The model depicts the conserved structural features of claudins and some of the known interactions and modifications. The domain arrangement of a claudin monomer: TMD1-EL1-TMD2-IL1-TMD3-EL2-TMD4 EL1, EL2 denote the extracellular loops and IL the intracellular loop respectively. The transmembrane domains 1 to 4 (TMD1 to TMD4) and the regions important for hepatitis C virus (HCV) entry and Clostridium perfringens enterotoxin (CPE) binding are shown.