4US4

Crystal Structure of the Bacterial NSS Member MhsT in an Occluded Inward-Facing State (lipidic cubic phase form)

4US4 の概要

• エントリーDOI: 10.2210/pdb4us4/pdb
• 関連するPDBエントリー: 4US3
• 分子名称: TRANSPORTER, TRYPTOPHAN, SODIUM ION, ... (6 entities in total)
• 機能のキーワード: transport protein, neurotransmitter, neurotransmitter sodium symporter family, leut fold, amino acid transporter, secondary transporter, membrane protein
• 由来する生物種: BACILLUS HALODURANS
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 49554.43

構造登録者

Malinauskaite, L.,Quick, M.,Reinhard, L.,Lyons, J.A.,Yano, H.,Javitch, J.A.,Nissen, P. (登録日: 2014-07-02, 公開日: 2014-09-24, 最終更新日: 2024-01-10)

主引用文献

Malinauskaite, L.,Quick, M.,Reinhard, L.,Lyons, J.A.,Yano, H.,Javitch, J.A.,Nissen, P.
A Mechanism for Intracellular Release of Na+ by Neurotransmitter/Sodium Symporters
Nat.Struct.Mol.Biol., 21:1006-, 2014

PubMed Abstract: Neurotransmitter/sodium symporters (NSSs) terminate synaptic signal transmission by Na+-dependent reuptake of released neurotransmitters. Key conformational states have been reported for the bacterial homolog LeuT and an inhibitor-bound Drosophila dopamine transporter. However, a coherent mechanism of Na+-driven transport has not been described. Here, we present two crystal structures of MhsT, an NSS member from Bacillus halodurans, in occluded inward-facing states with bound Na+ ions and L-tryptophan, providing insight into the cytoplasmic release of Na+. The switch from outward- to inward-oriented states is centered on the partial unwinding of transmembrane helix 5, facilitated by a conserved GlyX9Pro motif that opens an intracellular pathway for water to access the Na2 site. We propose a mechanism, based on our structural and functional findings, in which solvation through the TM5 pathway facilitates Na+ release from Na2 and the transition to an inward-open state.

PubMed: 25282149
DOI: 10.1038/NSMB.2894

実験手法

X-RAY DIFFRACTION (2.6 Å)