3MAM

A molecular switch changes the low to the high affinity state in the substrate binding protein AfProX

3MAM の概要

• エントリーDOI: 10.2210/pdb3mam/pdb
• 関連するPDBエントリー: 1SW2 1SW5
• 分子名称: Osmoprotection protein (ProX), TRIMETHYL GLYCINE, 1,2-ETHANEDIOL, ... (5 entities in total)
• 機能のキーワード: glycine betaine, binding protein, osmosensing, osmose, thermophilic, archaeon, transport protein
• 由来する生物種: Archaeoglobus fulgidus
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 31380.73

構造登録者

Tschapek, B.,Pittelkow, M.,Bremer, E.,Schmitt, L.,Smits, S.H. (登録日: 2010-03-24, 公開日: 2011-04-06, 最終更新日: 2023-11-15)

主引用文献

Tschapek, B.,Pittelkow, M.,Sohn-Bosser, L.,Holtmann, G.,Smits, S.H.,Gohlke, H.,Bremer, E.,Schmitt, L.
Arg149 Is Involved in Switching the Low Affinity, Open State of the Binding Protein AfProX into Its High Affinity, Closed State.
J.Mol.Biol., 411:36-52, 2011

PubMed Abstract: The substrate binding protein AfProX from the Archaeoglobus fulgidus ProU ATP binding cassette transporter is highly selective for the compatible solutes glycine betaine (GB) and proline betaine, which confer thermoprotection to this hyperthermophilic archaeon. A detailed mutational analysis of the substrate binding site revealed the contribution of individual amino acids for ligand binding. Replacement of Arg149 by an Ala residue displayed the largest impact on substrate binding. The structure of a mutant AfProX protein (substitution of Tyr111 with Ala) in complex with GB was solved in the open liganded conformation to gain further insight into ligand binding. In this crystal structure, GB is bound differently compared to the GB closed liganded structure of the wild-type AfProX protein. We found that a network of amino acid side chains communicates the presence of GB toward Arg149, which increases ligand affinity and induces domain closure of AfProX. These results were corroborated by molecular dynamics studies and support the view that Arg149 finalizes the high-affinity state of the AfProX substrate binding protein.

PubMed: 21664363
DOI: 10.1016/j.jmb.2011.05.039

実験手法

X-RAY DIFFRACTION (1.8 Å)