Structure of a presenilin family intramembrane aspartate protease

Presenilin, the catalytic component of γ-secretase, cleaves amyloid precursor protein into short peptides that form the plaques that are found in the brains of patients with Alzheimer’s disease; here the structure of a presenilin homologue is described, which will serve as a framework for understanding the mechanisms of action of presenilin and γ-secretase.