A fuzzy mitochondrial fusion apparatus comes into focus.

Membrane fusion is fundamental to eukaryotic life. Unlike the predominant intracellular fusion machineries that fuse compartments bounded by a single membrane, the mitochondrial fusion machinery must sequentially fuse the outer and inner mitochondrial membranes. These coordinated fusion events rely on a transmembrane GTPase that is known as fuzzy onions or Fzo. Recent studies have revealed that Fzo has an evolutionarily conserved role in mitochondrial fusion, and they take the first strides in determining the molecular nature of such a role.