Confirmation of the binding site of spermine to ATP13A2 protein

To better understand human ATP13A2-mediated polyamine transport, we used single-particle cryo-electron microscopy to solve high-resolution structures of human ATP13A2. Interestingly, we found polyamine binding at multiple sites distributed along the transmembrane regions in ATP13A2 protein, which has not been reported in previous studies. Therefore, we used cross-linking mass spectrometry (CX-MS) to confirm potential binding sites.