The integrin αE(CD103)β7 (αEβ7) is expressed by intraepithelial lymphocytes, dendritic cells and regulatory T cells. It plays an important role in the mucosal immune system by retaining lymphocytes within the epithelium and is involved in graft rejection, immunity against tumours and the generation of gut‐homing effector cells. In gut and breast, the ligand for αEβ7 is E‐cadherin but in human oral mucosa and skin, there is evidence that lymphocytes use an alternative, unknown, ligand. In the present study, the I domain of the human αE subunit, which contains the E‐cadherin‐binding site, was locked in a highly active, ‘open’ and an inactive, ‘closed’ conformation by the introduction of disulphide bonds and these domains were expressed as IgG Fc fusion proteins. αE fusion proteins recognize E‐cadherin, the only known ligand for αEβ7. This interaction was inhibited by an antibody that blocks the αE‐binding site on E‐cadherin and by the omission of Mn²⁺, which is essential for integrin function in vitro. The locked ‘open’ conformation of αE adhered to human oral and skin keratinocytes, including the E‐cadherin‐negative H376 cell line, and this was not inhibited by blocking antibody against the αEβ7‐binding site on E‐cadherin, providing further evidence for the existence of an alternative ligand for αEβ7 in skin and oral mucosa. The interaction with E‐cadherin and the alternative ligand was Mn²⁺ dependent and mediated by the metal ion‐dependent coordination site (MIDAS) of the locked ‘open’αE I domain, independently of the β7 subunit.