5C73

ATP-driven lipid-linked oligosaccharide flippase PglK in outward-occluded conformation

5C73 の概要

• エントリーDOI: 10.2210/pdb5c73/pdb
• 分子名称: Protein glycosylation K (1 entity in total)
• 機能のキーワード: abc transporter flippase, transport protein
• 由来する生物種: Campylobacter jejuni
• 細胞内の位置: Cell inner membrane ; Multi- pass membrane protein : Q0P9C4
• タンパク質・核酸の鎖数: 6
• 化学式量合計: 387526.06

構造登録者

Perez, C.,Locher, K.P. (登録日: 2015-06-24, 公開日: 2015-08-19, 最終更新日: 2024-01-10)

主引用文献

Perez, C.,Gerber, S.,Boilevin, J.,Bucher, M.,Darbre, T.,Aebi, M.,Reymond, J.L.,Locher, K.P.
Structure and mechanism of an active lipid-linked oligosaccharide flippase.
Nature, 524:433-438, 2015

PubMed Abstract: The flipping of membrane-embedded lipids containing large, polar head groups is slow and energetically unfavourable, and is therefore catalysed by flippases, the mechanisms of which are unknown. A prominent example of a flipping reaction is the translocation of lipid-linked oligosaccharides that serve as donors in N-linked protein glycosylation. In Campylobacter jejuni, this process is catalysed by the ABC transporter PglK. Here we present a mechanism of PglK-catalysed lipid-linked oligosaccharide flipping based on crystal structures in distinct states, a newly devised in vitro flipping assay, and in vivo studies. PglK can adopt inward- and outward-facing conformations in vitro, but only outward-facing states are required for flipping. While the pyrophosphate-oligosaccharide head group of lipid-linked oligosaccharides enters the translocation cavity and interacts with positively charged side chains, the lipidic polyprenyl tail binds and activates the transporter but remains exposed to the lipid bilayer during the reaction. The proposed mechanism is distinct from the classical alternating-access model applied to other transporters.

PubMed: 26266984
DOI: 10.1038/nature14953

実験手法

X-RAY DIFFRACTION (5.9 Å)