7MS0

Crystal structure of native Cg10062

7MS0 の概要

• エントリーDOI: 10.2210/pdb7ms0/pdb
• 分子名称: 4-oxalocrotonate tautomerase (2 entities in total)
• 機能のキーワード: tautomerase, hydrolase
• 由来する生物種: Corynebacterium glutamicum (Brevibacterium saccharolyticum)
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 19038.25

構造登録者

Nayebi, G.H.,Geiger, J.H.,Draths, K. (登録日: 2021-05-10, 公開日: 2022-02-02, 最終更新日: 2023-10-18)

主引用文献

Mathes Hewage, A.,Nayebi Gavgani, H.,Chi, D.,Qiu, B.,Geiger, J.H.,Draths, K.
Cg10062 Catalysis Forges a Link between Acetylenecarboxylic Acid and Bacterial Metabolism.
Biochemistry, 60:3879-3886, 2021

PubMed Abstract: The reliance of biocatalysis on plant-derived carbon for the synthesis of fuels and chemicals places it in direct competition with food production for resources. A potential solution to this problem is development of a metabolic link between alternative carbon sources and bacterial metabolism. Acetylenecarboxylic acid, which can be synthesized from methane and carbon dioxide, could enable this connection. It was previously shown that the enzyme Cg10062 catalyzes hydration of acetylenecarboxylate to afford malonate semialdehyde. Subsequent hydration-dependent decarboxylation to form acetaldehyde (81%), which was also observed, limits its biocatalytic usefulness. Several Cg10062 variants including E114Q and E114D do not catalyze decarboxylation and provide malonate semialdehyde as the sole product, albeit with substantially reduced catalytic activity. To identify an efficient enzyme capable of catalyzing acetylenecarboxylate hydration without decarboxylation, we undertook a mechanistic investigation of Cg10062 using mutagenesis, kinetic characterization, and X-ray crystallography. Cg10062 is a member of the tautomerase superfamily of enzymes, characterized by their β-α-β protein fold and an N-terminal proline residue situated at the center of the enzyme active site. Along with Pro-1, five additional active site residues (His-28, Arg-70, Arg-73, Tyr-103, and Glu-114) are required for Cg10062 activity. Incubation of crystals of four catalytically slow variants of Cg10062 with acetylenecarboxylate resulted in atomic resolution structures of Pro-1 bound to a complete set of intermediates, fully elaborating the detailed mechanism of the enzyme and establishing the process to involve covalent catalysis. Further, the intermediate-bound E114D structure explains the mechanism governing decarboxylation suppression. Together, these studies provide the most detailed picture of the catalytic mechanism of a tautomerase enzyme to date.

PubMed: 34910871
DOI: 10.1021/acs.biochem.1c00524

実験手法

X-RAY DIFFRACTION (1.37 Å)