Fig. 2: CryoEM structures of PCAT1 bound to nucleotides and Sub in lipid nanodiscs.

Both ADP (panel B) and ATP (panel E) stabilize an occluded (OC) conformation in the absence of Mg2+. Sub (panel C) and Mg2+ (panel A) shift the equilibrium toward the inward-facing (IF) conformation in the presence of ADP, whereas ATP/Sub bound PCAT1 remains in an OC conformation. PCAT1* denotes the cysteine-free PCAT1 (panel D).