Anion exchanger 1 (AE1), also known as band 3 or SLC4A1 or Band 3 anion transport protein or anion exchange protein exchanges chloride and bicarbonate across the red blood cell membrane, assisting in removing carbon dioxide from tissues. It also anchors the membrane skeleton [1]. Band 3's name comes from its appearance as the third major band on SDS-PAGE of red blood cell membrane proteins [2].
Its function has been studied for more than 150 years; even so, the first complete structure was not published until 2015 [3], and the first crystals grown without addition of an antibody were grown on the International Space Station [4].
Structural highlights
Band 3 functions as a . Each monomer contains fourteen transmembrane segments, as well as an intracellular domain that plays a gating role and a small extracellular domain.
