3NEP

1.55A resolution structure of malate dehydrogenase from Salinibacter ruber

3NEP の概要

• エントリーDOI: 10.2210/pdb3nep/pdb
• 分子名称: Malate dehydrogenase (2 entities in total)
• 機能のキーワード: malate dehydrogenase, halophile, molecular adpatation, nad, oxidoreductase, tricarboxylic acid cycle
• 由来する生物種: Salinibacter ruber
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 33286.59

構造登録者

Coquelle, N.,Madern, D. (登録日: 2010-06-09, 公開日: 2010-10-13, 最終更新日: 2023-09-06)

主引用文献

Coquelle, N.,Talon, R.,Juers, D.H.,Girard, E.,Kahn, R.,Madern, D.
Gradual adaptive changes of a protein facing high salt concentrations.
J.Mol.Biol., 404:493-505, 2010

PubMed Abstract: Several experimental techniques were applied to unravel fine molecular details of protein adaptation to high salinity. We compared four homologous enzymes, which suggested a new halo-adaptive state in the process of molecular adaptation to high-salt conditions. Together with comparative functional studies, the structure of malate dehydrogenase from the eubacterium Salinibacter ruber shows that the enzyme shares characteristics of a halo-adapted archaea-bacterial enzyme and of non-halo-adapted enzymes from other eubacterial species. The S. ruber enzyme is active at the high physiological concentrations of KCl but, unlike typical halo-adapted enzymes, remains folded and active at low salt concentrations. Structural aspects of the protein, including acidic residues at the surface, solvent-exposed hydrophobic surface, and buried hydrophobic surface, place it between the typical halo-adapted and non-halo-adapted proteins. The enzyme lacks inter-subunit ion-binding sites often seen in halo-adapted enzymes. These observations permit us to suggest an evolutionary pathway that is highlighted by subtle trade-offs to achieve an optimal compromise among solubility, stability, and catalytic activity.

PubMed: 20888835
DOI: 10.1016/j.jmb.2010.09.055

実験手法

X-RAY DIFFRACTION (1.551 Å)