+検索条件
-Structure paper
タイトル | Cryo-electron microscopy structures of human oligosaccharyltransferase complexes OST-A and OST-B. |
---|---|
ジャーナル・号・ページ | Science, Vol. 366, Issue 6471, Page 1372-1375, Year 2019 |
掲載日 | 2019年12月13日 |
著者 | Ana S Ramírez / Julia Kowal / Kaspar P Locher / |
PubMed 要旨 | Oligosaccharyltransferase (OST) catalyzes the transfer of a high-mannose glycan onto secretory proteins in the endoplasmic reticulum. Mammals express two distinct OST complexes that act in a ...Oligosaccharyltransferase (OST) catalyzes the transfer of a high-mannose glycan onto secretory proteins in the endoplasmic reticulum. Mammals express two distinct OST complexes that act in a cotranslational (OST-A) or posttranslocational (OST-B) manner. Here, we present high-resolution cryo-electron microscopy structures of human OST-A and OST-B. Although they have similar overall architectures, structural differences in the catalytic subunits STT3A and STT3B facilitate contacts to distinct OST subunits, DC2 in OST-A and MAGT1 in OST-B. In OST-A, interactions with TMEM258 and STT3A allow ribophorin-I to form a four-helix bundle that can bind to a translating ribosome, whereas the equivalent region is disordered in OST-B. We observed an acceptor peptide and dolichylphosphate bound to STT3B, but only dolichylphosphate in STT3A, suggesting distinct affinities of the two OST complexes for protein substrates. |
リンク | Science / PubMed:31831667 |
手法 | EM (単粒子) |
解像度 | 3.5 Å |
構造データ | EMDB-10110, PDB-6s7o: EMDB-10112, PDB-6s7t: |
化合物 | ChemComp-KZB: ChemComp-EGY: ChemComp-MG: ChemComp-KZE: ChemComp-0K3: |
由来 |
|
キーワード | TRANSFERASE (転移酵素) / N-glycosylation (N-結合型グリコシル化) / Oligosaccharyltransferase / OSTA / OSTB |