Crystal structure of human acid sphingomyelinase (ASM).
10">The ASM saposin domain and connector regions are tightly associated with the metallophosphatase catalytic domain.
15">The saposin domain undergoes hinge-opening and maintains its association with the catalytic domain upon membrane binding.
20">Membrane binding by the saposin domain guides the active site of the catalytic domain to the headgroups of the bilayer.
25">The model for ASM membrane binding provides structural insight into saposin-hydrolase complexes at bilayer surfaces.