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| | ==The Cryo-EM structure of a eukaryotic oligosaccharyl transferase complex== | | ==The Cryo-EM structure of a eukaryotic oligosaccharyl transferase complex== |
| - | <StructureSection load='6c26' size='340' side='right'caption='[[6c26]], [[Resolution|resolution]] 3.50Å' scene=''> | + | <SX load='6c26' size='340' side='right' viewer='molstar' caption='[[6c26]], [[Resolution|resolution]] 3.50Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[6c26]] is a 8 chain structure with sequence from [http://en.wikipedia.org/wiki/Baker's_yeast Baker's yeast]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6C26 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=6C26 FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[6c26]] is a 8 chain structure with sequence from [http://en.wikipedia.org/wiki/Baker's_yeast Baker's yeast]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6C26 OCA]. For a <b>guided tour on the structure components</b> use [http://proteopedia.org/fgij/fg.htm?mol=6C26 FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=BMA:BETA-D-MANNOSE'>BMA</scene>, <scene name='pdbligand=EGY:(4R,7R)-4-hydroxy-N,N,N-trimethyl-4,9-dioxo-7-[(undecanoyloxy)methyl]-3,5,8-trioxa-4lambda~5~-phosphadocosan-1-aminium'>EGY</scene>, <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene></td></tr> | + | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=BMA:BETA-D-MANNOSE'>BMA</scene>, <scene name='pdbligand=EGY:(4R,7R)-4-hydroxy-N,N,N-trimethyl-4,9-dioxo-7-[(undecanoyloxy)methyl]-3,5,8-trioxa-4lambda~5~-phosphadocosan-1-aminium'>EGY</scene>, <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene></td></tr> |
| | <tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Dolichyl-diphosphooligosaccharide--protein_glycotransferase Dolichyl-diphosphooligosaccharide--protein glycotransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.4.99.18 2.4.99.18] </span></td></tr> | | <tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Dolichyl-diphosphooligosaccharide--protein_glycotransferase Dolichyl-diphosphooligosaccharide--protein glycotransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.4.99.18 2.4.99.18] </span></td></tr> |
| - | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=6c26 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6c26 OCA], [http://pdbe.org/6c26 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=6c26 RCSB], [http://www.ebi.ac.uk/pdbsum/6c26 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=6c26 ProSAT]</span></td></tr> | + | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://proteopedia.org/fgij/fg.htm?mol=6c26 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6c26 OCA], [http://pdbe.org/6c26 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=6c26 RCSB], [http://www.ebi.ac.uk/pdbsum/6c26 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=6c26 ProSAT]</span></td></tr> |
| | </table> | | </table> |
| | == Function == | | == Function == |
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| | <references/> | | <references/> |
| | __TOC__ | | __TOC__ |
| - | </StructureSection> | + | </SX> |
| | [[Category: Baker's yeast]] | | [[Category: Baker's yeast]] |
| | [[Category: Dolichyl-diphosphooligosaccharide--protein glycotransferase]] | | [[Category: Dolichyl-diphosphooligosaccharide--protein glycotransferase]] |
| Structural highlights
Function
[OST3_YEAST] Essential subunit of the N-oligosaccharyl transferase (OST) complex which catalyzes the transfer of a high mannose oligosaccharide from a lipid-linked oligosaccharide donor to an asparagine residue within an Asn-X-Ser/Thr consensus motif in nascent polypeptide chains. N-glycosylation occurs cotranslationally and the complex associates with the Sec61 complex at the channel-forming translocon complex that mediates protein translocation across the endoplasmic reticulum (ER). All subunits are required for a maximal enzyme activity. [OST5_YEAST] Essential subunit of the N-oligosaccharyl transferase (OST) complex which catalyzes the transfer of a high mannose oligosaccharide from a lipid-linked oligosaccharide donor to an asparagine residue within an Asn-X-Ser/Thr consensus motif in nascent polypeptide chains. N-glycosylation occurs cotranslationally and the complex associates with the Sec61 complex at the channel-forming translocon complex that mediates protein translocation across the endoplasmic reticulum (ER). All subunits are required for a maximal enzyme activity. [OSTD_YEAST] Essential subunit of the N-oligosaccharyl transferase (OST) complex which catalyzes the transfer of a high mannose oligosaccharide from a lipid-linked oligosaccharide donor to an asparagine residue within an Asn-X-Ser/Thr consensus motif in nascent polypeptide chains. N-glycosylation occurs cotranslationally and the complex associates with the Sec61 complex at the channel-forming translocon complex that mediates protein translocation across the endoplasmic reticulum (ER). All subunits are required for a maximal enzyme activity. [OST1_YEAST] Essential subunit of the N-oligosaccharyl transferase (OST) complex which catalyzes the transfer of a high mannose oligosaccharide from a lipid-linked oligosaccharide donor to an asparagine residue within an Asn-X-Ser/Thr consensus motif in nascent polypeptide chains. N-glycosylation occurs cotranslationally and the complex associates with the Sec61 complex at the channel-forming translocon complex that mediates protein translocation across the endoplasmic reticulum (ER). All subunits are required for a maximal enzyme activity. [OSTB_YEAST] Essential subunit of the N-oligosaccharyl transferase (OST) complex which catalyzes the transfer of a high mannose oligosaccharide from a lipid-linked oligosaccharide donor to an asparagine residue within an Asn-X-Ser/Thr consensus motif in nascent polypeptide chains. N-glycosylation occurs cotranslationally and the complex associates with the Sec61 complex at the channel-forming translocon complex that mediates protein translocation across the endoplasmic reticulum (ER). All subunits are required for a maximal enzyme activity. [STT3_YEAST] Catalytic subunit of the N-oligosaccharyl transferase (OST) complex which catalyzes the transfer of a high mannose oligosaccharide to an asparagine residue within an Asn-X-Ser/Thr consensus motif in nascent polypeptide chains. N-glycosylation occurs cotranslationally and the complex associates with the Sec61 complex at the channel-forming translocon complex that mediates protein translocation across the endoplasmic reticulum (ER). All subunits are required for a maximal enzyme activity.[1] [OST4_YEAST] Essential subunit of the N-oligosaccharyl transferase (OST) complex which catalyzes the transfer of a high mannose oligosaccharide from a lipid-linked oligosaccharide donor to an asparagine residue within an Asn-X-Ser/Thr consensus motif in nascent polypeptide chains. N-glycosylation occurs cotranslationally and the complex associates with the Sec61 complex at the channel-forming translocon complex that mediates protein translocation across the endoplasmic reticulum (ER). All subunits are required for a maximal enzyme activity. OST4 is required for recruitment of OST3 or OST6 to the OST complex. It is essential for cell growth at 37 but not at 25 degrees Celsius. [OST2_YEAST] Essential subunit of the N-oligosaccharyl transferase (OST) complex which catalyzes the transfer of a high mannose oligosaccharide from a lipid-linked oligosaccharide donor to an asparagine residue within an Asn-X-Ser/Thr consensus motif in nascent polypeptide chains. N-glycosylation occurs cotranslationally and the complex associates with the Sec61 complex at the channel-forming translocon complex that mediates protein translocation across the endoplasmic reticulum (ER). All subunits are required for a maximal enzyme activity.
Publication Abstract from PubMed
N-glycosylation is a ubiquitous modification of eukaryotic secretory and membrane-bound proteins; about 90% of glycoproteins are N-glycosylated. The reaction is catalysed by an eight-protein oligosaccharyltransferase complex, OST, embedded in the ER membrane. Our understanding of eukaryotic protein N-glycosylation has been limited owing to the lack of high-resolution structures. Here we report a 3.5-A resolution cryo-EM structure of the Saccharomyces cerevisiae OST, revealing the structures of Ost1-5, Stt3, Wbp1, and Swp1. We found that seven phospholipids mediate many of the inter-subunit interactions, and an Stt3 N-glycan mediates interactions with Wbp1 and Swp1 in the lumen. Ost3 was found to mediate the OST-Sec61 translocon interface, funnelling the acceptor peptide towards the OST catalytic site as the nascent peptide emerges from the translocon. The structure provides novel insights into co-translational protein N-glycosylation and may facilitate the development of small-molecule inhibitors targeting this process.
The atomic structure of a eukaryotic oligosaccharyltransferase complex.,Bai L, Wang T, Zhao G, Kovach A, Li H Nature. 2018 Jan 22. pii: nature25755. doi: 10.1038/nature25755. PMID:29466327[2]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Yan Q, Lennarz WJ. Studies on the function of oligosaccharyl transferase subunits. Stt3p is directly involved in the glycosylation process. J Biol Chem. 2002 Dec 6;277(49):47692-700. Epub 2002 Sep 30. PMID:12359722 doi:http://dx.doi.org/10.1074/jbc.M208136200
- ↑ Bai L, Wang T, Zhao G, Kovach A, Li H. The atomic structure of a eukaryotic oligosaccharyltransferase complex. Nature. 2018 Jan 22. pii: nature25755. doi: 10.1038/nature25755. PMID:29466327 doi:http://dx.doi.org/10.1038/nature25755
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