2e3n | pdb_00002e3n

Crystal structure of CERT START domain in complex with C6-ceramide (P212121)

spinqualitylabelsall models 2e3n, resolution 1.40Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2e3n is a 1 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: 6CM Related: 2e3m, 2e3o, 2e3p, 2e3q, 2e3r, 2e3s Gene: CERT (Homo sapiens) Resources: FirstGlance, OCA, RCSB, PDBsum Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed In mammalian cells, ceramide is synthesized in the endoplasmic reticulum and transferred to the Golgi apparatus for conversion to sphingomyelin. Ceramide transport occurs in a nonvesicular manner and is mediated by CERT, a cytosolic 68-kDa protein with a C-terminal steroidogenic acute regulatory protein-related lipid transfer (START) domain. The CERT START domain efficiently transfers natural D-erythro-C16-ceramide, but not lipids with longer (C20) amide-acyl chains. The molecular mechanisms of ceramide specificity, both stereo-specific recognition and length limit, are not well understood. Here we report the crystal structures of the CERT START domain in its apo-form and in complex with ceramides having different acyl chain lengths. In these complex structures, one ceramide molecule is buried in a long amphiphilic cavity. At the far end of the cavity, the amide and hydroxyl groups of ceramide form a hydrogen bond network with specific amino acid residues that play key roles in stereo-specific ceramide recognition. At the head of the ceramide molecule, there is no extra space to accommodate additional bulky groups. The two aliphatic chains of ceramide are surrounded by the hydrophobic wall of the cavity, whose size and shape dictate the length limit for cognate ceramides. Furthermore, local high-crystallographic B-factors suggest that the alpha-3 and the Omega1 loop might work as a gate to incorporate the ceramide into the cavity. Thus, the structures demonstrate the structural basis for the mechanism by which CERT can distinguish ceramide from other lipid types yet still recognize multiple species of ceramides. Structural basis for specific lipid recognition by CERT responsible for nonvesicular trafficking of ceramide.,Kudo N, Kumagai K, Tomishige N, Yamaji T, Wakatsuki S, Nishijima M, Hanada K, Kato R Proc Natl Acad Sci U S A. 2008 Jan 15;105(2):488-93. Epub 2008 Jan 9. PMID:18184806 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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