4X2P

P. putida mandelate racemase in complex with 3-hydroxypyruvate

4X2P の概要

• エントリーDOI: 10.2210/pdb4x2p/pdb
• 分子名称: Mandelate racemase, 3-HYDROXYPYRUVIC ACID, MAGNESIUM ION, ... (4 entities in total)
• 機能のキーワード: racemase, enolase superfamily, isomerase
• 由来する生物種: Pseudomonas putida
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 41432.99

構造登録者

Wyatt, B.N.,St.Maurice, M. (登録日: 2014-11-26, 公開日: 2015-10-14, 最終更新日: 2024-11-20)

主引用文献

Nagar, M.,Wyatt, B.N.,St.Maurice, M.,Bearne, S.L.
Inactivation of Mandelate Racemase by 3-Hydroxypyruvate Reveals a Potential Mechanistic Link between Enzyme Superfamilies.
Biochemistry, 54:2747-2757, 2015

PubMed Abstract: Mandelate racemase (MR), a member of the enolase superfamily, catalyzes the Mg(2+)-dependent interconversion of the enantiomers of mandelate. Several α-keto acids are modest competitive inhibitors of MR [e.g., mesoxalate (Ki = 1.8 ± 0.3 mM) and 3-fluoropyruvate (Ki = 1.3 ± 0.1 mM)], but, surprisingly, 3-hydroxypyruvate (3-HP) is an irreversible, time-dependent inhibitor (kinact/KI = 83 ± 8 M(-1) s(-1)). Protection from inactivation by the competitive inhibitor benzohydroxamate, trypsinolysis and electrospray ionization tandem mass spectrometry analyses, and X-ray crystallographic studies reveal that 3-HP undergoes Schiff-base formation with Lys 166 at the active site, followed by formation of an aldehyde/enol(ate) adduct. Such a reaction is unprecedented in the enolase superfamily and may be a relic of an activity possessed by a promiscuous progenitor enzyme. The ability of MR to form and deprotonate a Schiff-base intermediate furnishes a previously unrecognized mechanistic link to other α/β-barrel enzymes utilizing Schiff-base chemistry and is in accord with the sequence- and structure-based hypothesis that members of the metal-dependent enolase superfamily and the Schiff-base-forming N-acetylneuraminate lyase superfamily and aldolases share a common ancestor.

PubMed: 25844917
DOI: 10.1021/acs.biochem.5b00221

実験手法

X-RAY DIFFRACTION (1.65 Å)