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-Structure paper
タイトル | Functional analysis of Ost3p and Ost6p containing yeast oligosaccharyltransferases. |
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ジャーナル・号・ページ | Glycobiology, Vol. 31, Issue 12, Page 1604-1615, Year 2021 |
掲載日 | 2021年12月30日 |
PubMed 要旨 | The oligosaccharyltransferase (OST) is the central enzyme in the N-glycosylation pathway. It transfers a defined oligosaccharide from a lipid-linker onto the asparagine side chain of proteins. The ...The oligosaccharyltransferase (OST) is the central enzyme in the N-glycosylation pathway. It transfers a defined oligosaccharide from a lipid-linker onto the asparagine side chain of proteins. The yeast OST consists of eight subunits and exists in two catalytically distinct isoforms that differ in one subunit, Ost3p or Ost6p. The cryo-electron microscopy structure of the Ost6p containing complex was found to be highly similar to the Ost3p containing OST. OST enzymes with altered Ost3p/Ost6p subunits were generated and functionally analyzed. The three C-terminal transmembrane helices were responsible for the higher turnover-rate of the Ost3p vs. the Ost6p containing enzyme in vitro and the more severe hypoglycosylation in Ost3p lacking strains in vivo. Glycosylation of specific OST target sites required the N-terminal thioredoxin domain of Ost3p or Ost6p. This Ost3p/Ost6p dependence was glycosylation site but not protein specific. We concluded that the Ost3p/Ost6p subunits modulate the catalytic activity of OST and provide additional specificity for OST substrate recognition. |
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手法 | EM (単粒子) |
解像度 | 3.46 Å |
構造データ | EMDB-12808, PDB-7oci: |
化合物 | ![]() ChemComp-PEE: ![]() ChemComp-NAG: ![]() ChemComp-AJP: ![]() ChemComp-MG: ![]() ChemComp-V8K: |
由来 |
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![]() | MEMBRANE PROTEIN / N-glycosylation / Yeast / Complex / Endoplasmic reticulum |