4TTG

Beta-galactosidase (E. coli) in the presence of potassium chloride.

4TTG の概要

• エントリーDOI: 10.2210/pdb4ttg/pdb
• 関連するPDBエントリー: 1DP0
• 分子名称: Beta-galactosidase, MAGNESIUM ION, POTASSIUM ION, ... (6 entities in total)
• 機能のキーワード: glycosidase, (alpha/beta)8 barrel, jelly roll, immunoglobulin, beta supersandwich, complex with potassium, hydrolase
• 由来する生物種: Escherichia coli
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 477467.91

構造登録者

Juers, D.H. (登録日: 2014-06-20, 公開日: 2015-03-25, 最終更新日: 2024-10-30)

主引用文献

Wheatley, R.W.,Juers, D.H.,Lev, B.B.,Huber, R.E.,Noskov, S.Y.
Elucidating factors important for monovalent cation selectivity in enzymes: E. coli beta-galactosidase as a model.
Phys Chem Chem Phys, 17:10899-10909, 2015

PubMed Abstract: Many enzymes require a specific monovalent cation (M(+)), that is either Na(+) or K(+), for optimal activity. While high selectivity M(+) sites in transport proteins have been extensively studied, enzyme M(+) binding sites generally have lower selectivity and are less characterized. Here we study the M(+) binding site of the model enzyme E. coli β-galactosidase, which is about 10 fold selective for Na(+) over K(+). Combining data from X-ray crystallography and computational models, we find the electrostatic environment predominates in defining the Na(+) selectivity. In this lower selectivity site rather subtle influences on the electrostatic environment become significant, including the induced polarization effects of the M(+) on the coordinating ligands and the effect of second coordination shell residues on the charge distribution of the primary ligands. This work expands the knowledge of ion selectivity in proteins to denote novel mechanisms important for the selectivity of M(+) sites in enzymes.

PubMed: 25820412
DOI: 10.1039/c4cp04952g

実験手法

X-RAY DIFFRACTION (1.6 Å)