4X2S

Crystal structure of 276S/M395R-GltPh in inward-facing conformation

4X2S の概要

• エントリーDOI: 10.2210/pdb4x2s/pdb
• 分子名称: 425aa long hypothetical proton glutamate symport protein, ASPARTIC ACID, SODIUM ION (3 entities in total)
• 機能のキーワード: amino acid secondary transporters, sodium coupled aspartate transporter, transport protein
• 由来する生物種: Pyrococcus horikoshii OT3
• タンパク質・核酸の鎖数: 3
• 化学式量合計: 134234.55

構造登録者

Akyuz, N.,Boudker, O. (登録日: 2014-11-26, 公開日: 2015-02-04, 最終更新日: 2023-09-27)

主引用文献

Akyuz, N.,Georgieva, E.R.,Zhou, Z.,Stolzenberg, S.,Cuendet, M.A.,Khelashvili, G.,Altman, R.B.,Terry, D.S.,Freed, J.H.,Weinstein, H.,Boudker, O.,Blanchard, S.C.
Transport domain unlocking sets the uptake rate of an aspartate transporter.
Nature, 518:68-73, 2015

PubMed Abstract: Glutamate transporters terminate neurotransmission by clearing synaptically released glutamate from the extracellular space, allowing repeated rounds of signalling and preventing glutamate-mediated excitotoxicity. Crystallographic studies of a glutamate transporter homologue from the archaeon Pyrococcus horikoshii, GltPh, showed that distinct transport domains translocate substrates into the cytoplasm by moving across the membrane within a central trimerization scaffold. Here we report direct observations of these 'elevator-like' transport domain motions in the context of reconstituted proteoliposomes and physiological ion gradients using single-molecule fluorescence resonance energy transfer (smFRET) imaging. We show that GltPh bearing two mutations introduced to impart characteristics of the human transporter exhibits markedly increased transport domain dynamics, which parallels an increased rate of substrate transport, thereby establishing a direct temporal relationship between transport domain motion and substrate uptake. Crystallographic and computational investigations corroborated these findings by revealing that the 'humanizing' mutations favour structurally 'unlocked' intermediate states in the transport cycle exhibiting increased solvent occupancy at the interface between the transport domain and the trimeric scaffold.

PubMed: 25652997
DOI: 10.1038/nature14158

実験手法

X-RAY DIFFRACTION (4.21 Å)