Anion/proton exchange transporter involved in iron and copper cation homeostasis. Involved in intracellular iron metabolism during growth on fermentable and non fermentable carbon sources. Required for proper copper-loading and maturation of multicopper oxidase FET3. Important for adjusting intracellular compartment pH to more alkaline pH under iron limitation. May also transport chloride ions through the plasma membrane. Homodimer (By similarity). Interacts with GET3. Proteolytically processed in the secretory pathway by protease KEX2 within the first extracellular loop. However, both the N- and C-terminal products of the cleavage reaction are required for assembly of a functional channel. Belongs to the chloride channel (TC 2.A.49) family. Was originally thought to be a voltage-gated ClC-type chloride channel.