6p28

Crystal structure of the MIR domain (aa 337-532) of the S. cerevisiae mannosyltransferase Pmt2

spinqualitylabelsall models 6p28, resolution 1.35Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 6p28 is a 1 chain structure with sequence from Saccharomyces cerevisiae. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.35Å Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Publication Abstract from PubMed In eukaryotes, a nascent peptide entering the endoplasmic reticulum (ER) is scanned by two Sec61 translocon-associated large membrane machines for protein N-glycosylation and protein O-mannosylation, respectively. While the structure of the eight-protein oligosaccharyltransferase complex has been determined recently, the structures of mannosyltransferases of the PMT family, which are an integral part of ER protein homeostasis, are still unknown. Here we report cryo-EM structures of the Saccharomyces cerevisiae Pmt1-Pmt2 complex bound to a donor and an acceptor peptide at 3.2-A resolution, showing that each subunit contains 11 transmembrane helices and a lumenal beta-trefoil fold termed the MIR domain. The structures reveal the substrate recognition model and confirm an inverting mannosyl-transferring reaction mechanism by the enzyme complex. Furthermore, we found that the transmembrane domains of Pmt1 and Pmt2 share a structural fold with the catalytic subunits of oligosaccharyltransferases, confirming a previously proposed evolutionary relationship between protein O-mannosylation and protein N-glycosylation. Structure of the eukaryotic protein O-mannosyltransferase Pmt1-Pmt2 complex.,Bai L, Kovach A, You Q, Kenny A, Li H Nat Struct Mol Biol. 2019 Jul 8. pii: 10.1038/s41594-019-0262-6. doi:, 10.1038/s41594-019-0262-6. PMID:31285605 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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