Heterologous expression, purification and biochemical characterization of a new endo-1,4-β-xylanase from Rhodothermaceae bacterium RA.

Autor: Liew KJ; Faculty of Science, Universiti Teknologi Malaysia, 81310, Skudai, Johor, Malaysia., Ngooi CY; Faculty of Science, Universiti Teknologi Malaysia, 81310, Skudai, Johor, Malaysia., Shamsir MS; Faculty of Science, Universiti Teknologi Malaysia, 81310, Skudai, Johor, Malaysia., Sani RK; Department of Chemical and Biological Engineering, South Dakota School of Mines and Technology, Rapid City, USA., Chong CS; Faculty of Science, Universiti Teknologi Malaysia, 81310, Skudai, Johor, Malaysia., Goh KM; Faculty of Science, Universiti Teknologi Malaysia, 81310, Skudai, Johor, Malaysia. Electronic address: gohkianmau@utm.my.
Jazyk: angličtina
Zdroj: Protein expression and purification [Protein Expr Purif] 2019 Dec; Vol. 164, pp. 105464. Date of Electronic Publication: 2019 Aug 01.
DOI: 10.1016/j.pep.2019.105464
Abstrakt: Xylanases (EC 3.2.1.8) are essential enzymes due to their applications in various industries such as textile, animal feed, paper and pulp, and biofuel industries. Halo-thermophilic Rhodothermaceae bacterium RA was previously isolated from a hot spring in Malaysia. Genomic analysis revealed that this bacterium is likely to be a new genus of the family Rhodothermaceae. In this study, a xylanase gene (1140 bp) that encoded 379 amino acids from the bacterium was cloned and expressed in Escherichia coli BL21(DE3). Based on InterProScan, this enzyme XynRA1 contained a GH10 domain and a signal peptide sequence. XynRA1 shared low similarity with the currently known xylanases (the closest is 57.2-65.4% to Gemmatimonadetes spp.). The purified XynRA1 achieved maximum activity at pH 8 and 60 °C. The protein molecular weight was 43.1 kDa XynRA1 exhibited an activity half-life (t 1/2 ) of 1 h at 60 °C and remained stable at 50 °C throughout the experiment. However, it was NaCl intolerant, and various types of salt reduced the activity. This enzyme effectively hydrolyzed xylan (beechwood, oat spelt, and Palmaria palmata) and xylodextrin (xylotriose, xylotetraose, xylopentaose, and xylohexaose) to produce predominantly xylobiose. This xylanase is the first functionally characterized enzyme from the bacterium, and this work broadens the knowledge of GH10 xylanases.
(Copyright © 2019 Elsevier Inc. All rights reserved.)
Databáze: MEDLINE
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