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Crystal Structure and Functional Characterization of an Esterase (EaEST) from Exiguobacterium antarcticum

Cited 30 time in wos
Cited 26 time in scopus
Crystal Structure and Functional Characterization of an Esterase (EaEST) from Exiguobacterium antarcticum
Other Titles
극지 호냉성 박테리아 (Exiguobacterium antarcticum) 유래 EaEST 효소의 구조-기능연구
Lee, Chang Woo
Lee, Jun Hyuck
T. Doohun Kim
Park, Hyun
Sunghwan Kim
Shin, Seung Chul
Kim, Han-Woo
Bum Han Ryu
Wanki Yoo
Boo-Young Kim
Park, Sun-Ha
Sena Kwon
Science & Technology - Other Topics
Exiguobacterium antarcticumX-ray crystallographyesteraseperhydrolysis
Issue Date
Lee, Chang Woo, et al. 2017. "Crystal Structure and Functional Characterization of an Esterase (EaEST) from Exiguobacterium antarcticum". PLOS ONE, 12(1): 169540-0.
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 A, 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.
Appears in Collections  
2014-2016, Antarctic Organisms: Cold-Adaptation Mechanism and Its Application (14-16) / Park; Hyun (PE14070; PE15070; PE16070)
2017-2018, Polar Genomics 101 Project: Genome analysis of polar organisms and establishment of application platform (17-18) / Park, Hyun (PE17080; PE18080)
2016-2017, Developing analytical techniques for investigating changing permafrost ecosystems in the Arctic (16-17) / Kim, Mincheol (PN16082; PN17082)
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