Identification of a novel alkaline amylopullulanase from a gut metagenome of Hermetia illucens.
Identification of a novel alkaline amylopullulanase from a gut metagenome of Hermetia illucens.
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DOI：
10.1016/j.ijbiomac.2015.10.067
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发表时间：
2016
影响因子：
8.2
通讯作者：
Young-Seok Lee;Sohyeon Seo;Sang-Hong Yoon;Su-yeon Kim;B. Hahn;Joon-Soo Sim;Bon-sung Koo;Chang-Muk Lee
中科院分区：
文献类型：
--
作者：
Young-Seok Lee;Sohyeon Seo;Sang-Hong Yoon;Su-yeon Kim;B. Hahn;Joon-Soo Sim;Bon-sung Koo;Chang-Muk Lee
通过基于功能的元基因组筛选，从食蟹肠道微生物区系中鉴定出一个新的普鲁兰酶基因PulSS4。PulSS4基因开放阅读框为4455个碱基，编码1484个氨基酸的成熟蛋白，信号肽序列为44个氨基酸。所推导的PulSS4基因的氨基酸序列与木霉淀粉酶的同源性为51%，与已知的普鲁兰酶没有显著的同源性。保守结构域分析表明，该酶为普鲁兰酶II型，其活性部位分别位于N-末端和C-末端的淀粉酶结构域。PulSS4在10~50℃温度范围内活性最高，40℃时活性最好，在pH 6.5~10.5范围内活性最好，最适pH为9.0，在30℃下，在5~11的较宽pH范围内保持80%以上的活性，并在24 h内对包括10%的极性有机溶剂和1%的非离子洗涤剂在内的多种化学试剂具有高度的稳定性。总体而言，PulSS4有望在需要在中温和碱性条件下具有高活性的生物技术行业中具有很强的应用潜力。
A novel pullulanase gene,PulSS4, was identified from the gut microflora ofHermetia illucensby a function-based metagenome screening. ThePulSS4gene had an open reading frame of 4455 base pairs, and encoded a mature protein of 1484 amino acids, with a signal peptide sequence of 44 amino acids. The deduced amino acid sequence ofPulSS4gene showed 51% identity with that of the amylopullulanase ofAmphibacillus xylanus, exhibiting no significant sequence homology to already known pullulanases. A conserved domain analysis revealed it to be a pullulanase type II with respective active sites at the N-terminal pullulanase and C-terminal amylase domain. PulSS4 was active in the temperature range of 10–50 °C, with an optimum activity at 40 °C. It was active in the pH range of 6.5–10.5, with optimum pH at 9.0, and retained more than 80% of its original activity in a broad pH range of 5–11 for 24 h at 30 °C. Also, PulSS4 was highly stable against many different chemical reagents, including 10% polar organic solvents and 1% non-ionic detergents. Overall, PulSS4 is expected to have the strong potential for application in biotechnological industries that require high activity at moderate temperature and alkaline conditions.