In the yeast, ATG7 appears to be required for fusion of peroxisomal and vacuolar membranes. ATG7 shows homology to the ATP-binding and catalytic sites of the E1 ubiquitin activating enzymes. The process of autophagy is characterized as a non-selective degradation of cytoplasmic proteins into membrane stuctures called autophagosomes, and it is dependent on several proteins, including the autophagy proteins APG5 and APG. This conjugation reaction is mediated by the ubiquitin E1-like enzyme Atg7 and the E2-like enzyme Atg10.
