Fig. 3: Structural analysis of hATP13A2 in E2-Pi state.
From: Conformational cycle of human polyamine transporter ATP13A2
a The overall structure of ATP13A2 in the E2-Pi state. The EM density of SPM is shown as ChimeraX’s “solid” (orange) representation at Site2. b Electrostatic potential surface of the inward-open cavity within the E2-Pi structure. TM2 and TM4b falling apart makes a large cavity. The SPM molecule is shown as sticks. The yellow-dotted line represents the extent of the SPM binding pocket. c Representation of the SPM binding pocket of the E2-Pi conformation at Site2. The cryo-EM density for the bound SPM is shown in mesh, and residues contacting SPM are shown as sticks. d Potential cross-linking sites for BS3 around Site2.The dashed lines show the distance between Lysine (K) and SPM. K506 and K420 covalently cross-linked with the SPM. e Dose–response curves showing the SPM-induced ATPase activity of purified WT hATP13A2 or mutants. Data points represent the mean ± SD of three (F419A) or four (WT and Y240A) measurements. Lines are fitting by nonlinear regression of the Michaelis–Menten equation. Source data are provided as a Source Data file.
