7D0I
Cryo-EM structure of Schizosaccharomyces pombe Atg9
Summary for 7D0I
| Entry DOI | 10.2210/pdb7d0i/pdb |
| EMDB information | 30535 |
| Descriptor | Autophagy-related protein 9, Lauryl Maltose Neopentyl Glycol (2 entities in total) |
| Functional Keywords | autophagy, membrane protein, unknown function |
| Biological source | Schizosaccharomyces pombe (strain 972 / ATCC 24843) (Fission yeast) |
| Total number of polymer chains | 6 |
| Total formula weight | 508515.29 |
| Authors | Matoba, K.,Tsutsumi, A.,Kikkawa, M.,Noda, N.N. (deposition date: 2020-09-10, release date: 2020-10-28, Last modification date: 2024-03-27) |
| Primary citation | Matoba, K.,Kotani, T.,Tsutsumi, A.,Tsuji, T.,Mori, T.,Noshiro, D.,Sugita, Y.,Nomura, N.,Iwata, S.,Ohsumi, Y.,Fujimoto, T.,Nakatogawa, H.,Kikkawa, M.,Noda, N.N. Atg9 is a lipid scramblase that mediates autophagosomal membrane expansion. Nat.Struct.Mol.Biol., 27:1185-1193, 2020 Cited by PubMed Abstract: The molecular function of Atg9, the sole transmembrane protein in the autophagosome-forming machinery, remains unknown. Atg9 colocalizes with Atg2 at the expanding edge of the isolation membrane (IM), where Atg2 receives phospholipids from the endoplasmic reticulum (ER). Here we report that yeast and human Atg9 are lipid scramblases that translocate phospholipids between outer and inner leaflets of liposomes in vitro. Cryo-EM of fission yeast Atg9 reveals a homotrimer, with two connected pores forming a path between the two membrane leaflets: one pore, located at a protomer, opens laterally to the cytoplasmic leaflet; the other, at the trimer center, traverses the membrane vertically. Mutation of residues lining the pores impaired IM expansion and autophagy activity in yeast and abolished Atg9's ability to transport phospholipids between liposome leaflets. These results suggest that phospholipids delivered by Atg2 are translocated from the cytoplasmic to the luminal leaflet by Atg9, thereby driving autophagosomal membrane expansion. PubMed: 33106658DOI: 10.1038/s41594-020-00518-w PDB entries with the same primary citation |
| Experimental method | ELECTRON MICROSCOPY (3 Å) |
Structure validation
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