4AO8

PEG-bound complex of a novel cold-adapted esterase from an Arctic intertidal metagenomic library

4AO8 の概要

• エントリーDOI: 10.2210/pdb4ao8/pdb
• 関連するPDBエントリー: 4AO6 4AO7
• 分子名称: ESTERASE, DI(HYDROXYETHYL)ETHER (3 entities in total)
• 機能のキーワード: hydrolase, thermo label
• 由来する生物種: UNIDENTIFIED
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 28400.31

構造登録者

Fu, J.,Leiros, H.-K.S.,Pascale, D.d.,Johnson, K.A.,Blencke, H.M.,Landfald, B. (登録日: 2012-03-23, 公開日: 2012-08-08, 最終更新日: 2024-05-08)

主引用文献

Fu, J.,Leiros, H.-K.S.,De Pascale, D.,Johnson, K.A.,Blencke, H.M.,Landfald, B.
Functional and Structural Studies of a Novel Cold-Adapted Esterase from an Arctic Intertidal Metagenomic Library.
Appl.Microbiol.Biotechnol., 97:3965-, 2013

PubMed Abstract: A novel cold-adapted lipolytic enzyme gene, est97, was identified from a high Arctic intertidal zone sediment metagenomic library. The deduced amino acid sequence of Est97 showed low similarity with other lipolytic enzymes, the maximum being 30 % identity with a putative lipase from Vibrio caribbenthicus. Common features of lipolytic enzymes, such as the GXSXG sequence motif, were detected. The gene product was over-expressed in Escherichia coli and purified. The recombinant Est97 (rEst97) hydrolysed various ρ-nitrophenyl esters with the best substrate being ρ-nitrophenyl hexanoate (K m and k cat of 39 μM and 25.8 s(-1), respectively). This esterase activity of rEst97 was optimal at 35 °C and pH 7.5 and the enzyme was unstable at temperatures above 25 °C. The apparent melting temperature, as determined by differential scanning calorimetry was 39 °C, substantiating Est97 as a cold-adapted esterase. The crystal structure of rEst97 was determined by the single wavelength anomalous dispersion method to 1.6 Å resolution. The protein was found to have a typical α/β-hydrolase fold with Ser144-His226-Asp197 as the catalytic triad. A suggested, relatively short lid domain of rEst97 is composed of residues 80-114, which form an α-helix and a disordered loop. The cold adaptation features seem primarily related to a high number of methionine and glycine residues and flexible loops in the high-resolution structures.

PubMed: 22832985
DOI: 10.1007/S00253-012-4276-9

実験手法

X-RAY DIFFRACTION (1.61 Å)