Structure, lipid scrambling activity and role in autophagosome formation of ATG9A.

De novo formation of the double-membrane compartment autophagosome is seeded by small vesicles carrying membrane protein autophagy-related 9 (ATG9), the function of which remains unknown. Here we find that ATG9A scrambles phospholipids of membranes in vitro. Cryo-EM structures of human ATG9A reveal a trimer with a solvated central pore, which is connected laterally to the cytosol through the cavity within each protomer.

Adaptive Partitioning QM/MM for Molecular Dynamics Simulations: 6. Proton Transport through a Biological Channel.

Adaptive quantum-mechanics/molecular-mechanics (QM/MM) dynamics simulations feature on-the-fly reclassification of atoms as QM or MM continuously and smoothly as trajectories are propagated. This allows one to use small, mobile QM subsystems, the contents of which are dynamically updated as needed. In this work, we report the first adaptive QM/MM simulations of H transfer through a biological channel, in particular, the protein EcCLC, a chloride channel (CLC) Cl/H antiporter derived from E.