ATG3 proteins possess a unique amphipathic α-helix essential for the Atg8/LC3 lipidation reaction.

In our recent paper, we uncovered that ATG3 exhibits a large degree of structural dynamics on autophagic membranes to efficiently carry out LC3 lipidation. ATG3 proteins possess an amphipathic α-helix (AH) identified by a small number of bulky and hydrophobic residues. This biophysical fingerprint allows for transient membrane association of ATG3 and facilitates its enzymatic reaction. This study will pave the way for a structural and mechanistic understanding of how membrane association of ATG proteins is orchestrated during autophagosome formation.