Cryo-EM structures of the ABCA4 importer reveal mechanisms underlying substrate binding and Stargardt disease

Abstract

ABCA4 is an ATP-binding cassette (ABC) transporter that flips N-retinylidenephosphatidylethanolamine (N-Ret-PE) to the cytoplasmic leaflet of photoreceptor membranes. ABCA4 mutations are associated with loss of vision. Here, structures of ABCA4 with and without substrate bound provide insight into N-Ret-PE binding and suggest a lateral access mechanism.