6c26: Difference between revisions
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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=''> | <StructureSection load='6c26' size='340' side='right'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://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=6C26 FirstGlance]. <br> | ||
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[[Category: Baker's yeast]] | [[Category: Baker's yeast]] | ||
[[Category: Dolichyl-diphosphooligosaccharide--protein glycotransferase]] | [[Category: Dolichyl-diphosphooligosaccharide--protein glycotransferase]] | ||
[[Category: Large Structures]] | |||
[[Category: Bai, L]] | [[Category: Bai, L]] | ||
[[Category: Li, H]] | [[Category: Li, H]] |
Revision as of 12:29, 18 December 2019
The Cryo-EM structure of a eukaryotic oligosaccharyl transferase complexThe Cryo-EM structure of a eukaryotic oligosaccharyl transferase complex
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 PubMedN-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
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