5H3H

Esterase (EaEST) from Exiguobacterium antarcticum

5H3H の概要

• エントリーDOI: 10.2210/pdb5h3h/pdb
• 分子名称: Abhydrolase domain-containing protein, ETHANEPEROXOIC ACID (3 entities in total)
• 機能のキーワード: perhydrolase, hydrolase
• 由来する生物種: Exiguobacterium antarcticum (strain B7)
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 60860.39

構造登録者

Lee, J.H.,Lee, C.W. (登録日: 2016-10-24, 公開日: 2017-01-11, 最終更新日: 2024-05-29)

主引用文献

Lee, C.W.,Kwon, S.,Park, S.H.,Kim, B.Y.,Yoo, W.,Ryu, B.H.,Kim, H.W.,Shin, S.C.,Kim, S.,Park, H.,Kim, T.D.,Lee, J.H.
Crystal Structure and Functional Characterization of an Esterase (EaEST) from Exiguobacterium antarcticum.
Plos One, 12:e0169540-e0169540, 2017

PubMed Abstract: A novel microbial esterase, EaEST, from a psychrophilic bacterium Exiguobacterium antarcticum B7, was identified and characterized. To our knowledge, this is the first report describing structural analysis and biochemical characterization of an esterase isolated from the genus Exiguobacterium. Crystal structure of EaEST, determined at a resolution of 1.9 Å, showed that the enzyme has a canonical α/β hydrolase fold with an α-helical cap domain and a catalytic triad consisting of Ser96, Asp220, and His248. Interestingly, the active site of the structure of EaEST is occupied by a peracetate molecule, which is the product of perhydrolysis of acetate. This result suggests that EaEST may have perhydrolase activity. The activity assay showed that EaEST has significant perhydrolase and esterase activity with respect to short-chain p-nitrophenyl esters (≤C8), naphthyl derivatives, phenyl acetate, and glyceryl tributyrate. However, the S96A single mutant had low esterase and perhydrolase activity. Moreover, the L27A mutant showed low levels of protein expression and solubility as well as preference for different substrates. On conducting an enantioselectivity analysis using R- and S-methyl-3-hydroxy-2-methylpropionate, a preference for R-enantiomers was observed. Surprisingly, immobilized EaEST was found to not only retain 200% of its initial activity after incubation for 1 h at 80°C, but also retained more than 60% of its initial activity after 20 cycles of reutilization. This research will serve as basis for future engineering of this esterase for biotechnological and industrial applications.

PubMed: 28125606
DOI: 10.1371/journal.pone.0169540

実験手法

X-RAY DIFFRACTION (1.9 Å)