A wall assembly of a combustor for a turbine engine includes a shell and a liner and a sealing interface structure. A cooling cavity is defined between the shell and liner and the sealing interface structure functions to minimize leakage out of the cooling cavity. The sealing interface structure may have a sealing width that is equal to or greater than twice the thickness of the liner and/or may include a chamber located between longitudinal segments of the sealing interface structure that inhibits leakage.