8C81

Cryo-EM structure of the yeast SPT-Orm1-Sac1 complex

Summary for 8C81

• Entry DOI: 10.2210/pdb8c81/pdb
• EMDB information: 16468
• Descriptor: Protein ORM1, Serine palmitoyltransferase 1, Serine palmitoyltransferase 2, ... (9 entities in total)
• Functional Keywords: serine-palmitoyl-transferase, spt, orm-protein, transferase
• Biological source: Saccharomyces cerevisiae (baker's yeast); More
• Total number of polymer chains: 5
• Total formula weight: 237500.07

Authors

Schaefer, J.,Koerner, C.,Parey, K.,Januliene, D.,Moeller, A.,Froehlich, F. (deposition date: 2023-01-18, release date: 2023-10-11)

Primary citation

Schafer, J.H.,Korner, C.,Esch, B.M.,Limar, S.,Parey, K.,Walter, S.,Januliene, D.,Moeller, A.,Frohlich, F.
Structure of the ceramide-bound SPOTS complex.
Nat Commun, 14:6196-6196, 2023

PubMed Abstract: Sphingolipids are structural membrane components that also function in cellular stress responses. The serine palmitoyltransferase (SPT) catalyzes the rate-limiting step in sphingolipid biogenesis. Its activity is tightly regulated through multiple binding partners, including Tsc3, Orm proteins, ceramides, and the phosphatidylinositol-4-phosphate (PI4P) phosphatase Sac1. The structural organization and regulatory mechanisms of this complex are not yet understood. Here, we report the high-resolution cryo-EM structures of the yeast SPT in complex with Tsc3 and Orm1 (SPOT) as dimers and monomers and a monomeric complex further carrying Sac1 (SPOTS). In all complexes, the tight interaction of the downstream metabolite ceramide and Orm1 reveals the ceramide-dependent inhibition. Additionally, observation of ceramide and ergosterol binding suggests a co-regulation of sphingolipid biogenesis and sterol metabolism within the SPOTS complex.

PubMed: 37794019
DOI: 10.1038/s41467-023-41747-z

Experimental method

ELECTRON MICROSCOPY (3.3 Å)