5AFD

Native structure of N-acetylneuramininate lyase (sialic acid aldolase) from Aliivibrio salmonicida

5AFD の概要

• エントリーDOI: 10.2210/pdb5afd/pdb
• 分子名称: N-ACETYLNEURAMINATE LYASE, GLYCEROL, 1,2-ETHANEDIOL, ... (4 entities in total)
• 機能のキーワード: lyase, sialic acid aldolase, alkaline, cold active, psychrophile
• 由来する生物種: ALIIVIBRIO SALMONICIDA
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 32931.64

構造登録者

Gurung, M.K.,Altermark, B.,Rader, I.L.U.,Helland, R.,Smalas, A.O. (登録日: 2015-01-21, 公開日: 2016-03-02, 最終更新日: 2024-01-10)

主引用文献

Gurung, M.K.,Altermark, B.,Helland, R.,Smalas, A.O.,Raeder, I.L.U.
Features and structure of a cold active N-acetylneuraminate lyase.
Plos One, 14:e0217713-e0217713, 2019

PubMed Abstract: N-acetylneuraminate lyases (NALs) are enzymes that catalyze the reversible cleavage and synthesis of sialic acids. They are therefore commonly used for the production of these high-value sugars. This study presents the recombinant production, together with biochemical and structural data, of the NAL from the psychrophilic bacterium Aliivibrio salmonicida LFI1238 (AsNAL). Our characterization shows that AsNAL possesses high activity and stability at alkaline pH. We confirm that these properties allow for the use in a one-pot reaction at alkaline pH for the synthesis of N-acetylneuraminic acid (Neu5Ac, the most common sialic acid) from the inexpensive precursor N-acetylglucosamine. We also show that the enzyme has a cold active nature with an optimum temperature for Neu5Ac synthesis at 20°C. The equilibrium constant for the reaction was calculated at different temperatures, and the formation of Neu5Ac acid is favored at low temperatures, making the cold active enzyme a well-suited candidate for use in such exothermic reactions. The specific activity is high compared to the homologue from Escherichia coli at three tested temperatures, and the enzyme shows a higher catalytic efficiency and turnover number for cleavage at 37°C. Mutational studies reveal that amino acid residue Asn 168 is important for the high kcat. The crystal structure of AsNAL was solved to 1.65 Å resolution and reveals a compact, tetrameric protein similar to other NAL structures. The data presented provides a framework to guide further optimization of its application in sialic acid production and opens the possibility for further design of the enzyme.

PubMed: 31185017
DOI: 10.1371/journal.pone.0217713

実験手法

X-RAY DIFFRACTION (1.65 Å)