8F6K

Cryo-EM structure of a Zinc-loaded H263A/D287A mutant of the YiiP-Fab complex

8F6K の概要

• エントリーDOI: 10.2210/pdb8f6k/pdb
• EMDBエントリー: 28886
• 分子名称: Cadmium and zinc efflux pump FieF, ZINC ION (2 entities in total)
• 機能のキーワード: zinc transporter, cation diffusion facilitator, membrane protein, transport protein
• 由来する生物種: Shewanella oneidensis
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 129758.18

構造登録者

Lopez-Redondo, M.L.,Hussein, A.K.,Stokes, D.L. (登録日: 2022-11-16, 公開日: 2023-02-08, 最終更新日: 2024-08-21)

主引用文献

Hussein, A.,Fan, S.,Lopez-Redondo, M.,Kenney, I.,Zhang, X.,Beckstein, O.,Stokes, D.L.
Energy coupling and stoichiometry of Zn 2+ /H + antiport by the prokaryotic cation diffusion facilitator YiiP.
Elife, 12:-, 2023

PubMed Abstract: YiiP from Shewanella oneidensis is a prokaryotic Zn/H antiporter that serves as a model for the Cation Diffusion Facilitator (CDF) superfamily, members of which are generally responsible for homeostasis of transition metal ions. Previous studies of YiiP as well as related CDF transporters have established a homodimeric architecture and the presence of three distinct Zn binding sites named A, B, and C. In this study, we use cryo-EM, microscale thermophoresis and molecular dynamics simulations to address the structural and functional roles of individual sites as well as the interplay between Zn binding and protonation. Structural studies indicate that site C in the cytoplasmic domain is primarily responsible for stabilizing the dimer and that site B at the cytoplasmic membrane surface controls the structural transition from an inward facing conformation to an occluded conformation. Binding data show that intramembrane site A, which is directly responsible for transport, has a dramatic pH dependence consistent with coupling to the proton motive force. A comprehensive thermodynamic model encompassing Zn binding and protonation states of individual residues indicates a transport stoichiometry of 1 Zn to 2-3 H depending on the external pH. This stoichiometry would be favorable in a physiological context, allowing the cell to use the proton gradient as well as the membrane potential to drive the export of Zn.

PubMed: 37906094
DOI: 10.7554/eLife.87167

実験手法

ELECTRON MICROSCOPY (3.46 Å)