ジャーナル: Nat Commun / 年: 2025 タイトル: Cryo-EM structures of a protein pore reveal a cluster of cholesterol molecules and diverse roles of membrane lipids. 著者: Gašper Šolinc / Marija Srnko / Franci Merzel / Ana Crnković / Mirijam Kozorog / Marjetka Podobnik / Gregor Anderluh / 要旨: The structure and function of membrane proteins depend on their interactions with lipids that constitute membranes. Actinoporins are α-pore-forming proteins that bind preferentially to sphingomyelin- ...The structure and function of membrane proteins depend on their interactions with lipids that constitute membranes. Actinoporins are α-pore-forming proteins that bind preferentially to sphingomyelin-containing membranes, where they oligomerize and form transmembrane pores. Through a comprehensive cryo-electron microscopic analysis of a pore formed by an actinoporin Fav from the coral Orbicella faveolata, we show that the octameric pore interacts with 112 lipids in the upper leaflet of the membrane, reveal the roles of lipids, and demonstrate that the actinoporin surface is suited for binding multiple receptor sphingomyelin molecules. When cholesterol is present in the membrane, it forms a cluster of four molecules associated with each protomer. Atomistic simulations support the structural data and reveal additional effects of the pore on the lipid membrane. These data reveal a complex network of protein-lipid and lipid-lipid interactions and an underrated role of lipids in the structure and function of transmembrane protein complexes.
分子量: 23002.561 Da / 分子数: 1 / 変異: dN53 / 由来タイプ: 組換発現 詳細: This protein was expressed with an N-terminal deletion of 53 residues compared to the wild type. The deletion construct has three additional residues at the N-terminal (GHM) from the expression system. 由来: (組換発現) Orbicella faveolata (無脊椎動物) プラスミド: pET28a (+) 詳細 (発現宿主): modified pET28a (+) plasmid with the N-terminal 6-histidine tag and TEV restriction site ENLYFQGHM 発現宿主: Escherichia coli BL21(DE3) (大腸菌)