The structure and function of P5A-ATPases
Endoplasmic reticulum (ER) membrane resident P5A-ATPases broadly affect protein biogenesis and quality control, and yet their molecular function remains debated. Here, we report cryo-EM structures of a P5A-ATPase, CtSpf1, covering multiple transport intermediates of the E1 → E1-ATP → E1P-ADP → E1P → E2P → E2.Pi → E2 → E1 cycle. In the E2P and E2.Pi states a cleft spans the entire membrane, holding