8GYW

Cryo-EM structure of human CEPT1 complexed with CDP-choline

Summary for 8GYW

• Entry DOI: 10.2210/pdb8gyw/pdb
• EMDB information: 34378
• Descriptor: Choline/ethanolaminephosphotransferase 1, MAGNESIUM ION, [2-CYTIDYLATE-O'-PHOSPHONYLOXYL]-ETHYL-TRIMETHYL-AMMONIUM (3 entities in total)
• Functional Keywords: cept1, choline/ethanolamine phosphotransferase, lipid binding protein
• Biological source: Homo sapiens (human)
• Total number of polymer chains: 2
• Total formula weight: 86464.05

Authors

Qian, H.W.,Wang, Z.H. (deposition date: 2022-09-24, release date: 2023-03-22, Last modification date: 2023-10-04)

Primary citation

Wang, Z.,Yang, M.,Yang, Y.,He, Y.,Qian, H.
Structural basis for catalysis of human choline/ethanolamine phosphotransferase 1.
Nat Commun, 14:2529-2529, 2023

PubMed Abstract: Phosphatidylcholine (PC) and phosphatidylethanolamine (PE) are two primary components of the eukaryotic membrane and play essential roles in the maintenance of membrane integrity, lipid droplet biogenesis, autophagosome formation, and lipoprotein formation and secretion. Choline/ethanolamine phosphotransferase 1 (CEPT1) catalyzes the last step of the biosynthesis of PC and PE in the Kennedy pathway by transferring the substituted phosphate group from CDP-choline/ethanolamine to diacylglycerol. Here, we present the cryo-EM structures of human CEPT1 and its complex with CDP-choline at resolutions of 3.7 Å and 3.8 Å, respectively. CEPT1 is a dimer with 10 transmembrane segments (TMs) in each protomer. TMs 1-6 constitute a conserved catalytic domain with an interior hydrophobic chamber accommodating a PC-like density. Structural observations and biochemical characterizations suggest that the hydrophobic chamber coordinates the acyl tails during the catalytic process. The PC-like density disappears in the structure of the complex with CDP-choline, suggesting a potential substrate-triggered product release mechanism.

PubMed: 37137909
DOI: 10.1038/s41467-023-38290-2

Experimental method

ELECTRON MICROSCOPY (3.9 Å)