Optimal secretion of alkali-tolerant xylanase in Bacillus subtilis by signal peptide screening
Optimal secretion of alkali-tolerant xylanase in Bacillus subtilis by signal peptide screening
复制标题
通过信号肽筛选优化枯草芽孢杆菌耐碱木聚糖酶的分泌
DOI：
10.1007/s00253-016-7615-4
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发表时间：
2016-10-01
影响因子：
5
通讯作者：
Zhao, Xin
中科院分区：
文献类型：
--
作者：
Zhang, Weiwei;Yang, Mingming;Zhao, Xin
木聚糖酶是工业上用于木聚糖消化的重要酶。我们实验性地筛选了超过114个Sec和24个达特途径信号肽，用两种不同的启动子，用于在枯草芽孢杆菌宿主中从短小芽孢杆菌BYG最佳生产碱性活性木聚糖酶（XynBYG）。虽然两种启动子产生高度一致的分泌水平（0.97皮尔逊相关系数），但发现Sec途径比达特途径更有效地用于XynBYG分泌。此外，XynBYG分泌的最佳信号肽（phoB）被发现不同于先前研究中报道的角质酶和酯酶的最佳肽。偏最小二乘回归分析进一步鉴定了几个统计学上重要的变量：螺旋性质、氨基酸组成偏差和信号P中的区分得分。这些变量解释了通过不同信号肽观察到的XynBYG分泌产率的23%差异。结果还表明，信号肽的螺旋倾向在富含β的木聚糖酶中起着重要作用，但在富含螺旋的角质酶中不起作用，这表明信号肽与其货物蛋白之间的构象的偶联用于最佳分泌。
Xylanases are industrially important enzymes for xylan digestion. We experimentally screened over 114 Sec and 24 Tat pathway signal peptides, with two different promoters, for optimal production of an alkaline active xylanase (XynBYG) from Bacillus pumilus BYG in a Bacillus subtilis host. Though both promoters yielded highly consistent secretion levels (0.97 Pearson correlation coefficient), the Sec pathway was found to be more efficient than the Tat pathway for XynBYG secretion. Furthermore, the optimal signal peptide (phoB) for XynBYG secretion was found to be different from the optimal peptides for cutinase and esterase reported in previous studies. A partial least squares regression analysis further identified several statistically important variables: helical properties, amino acid composition bias, and the discrimination score in Signal P. These variables explain the observed 23 % variance in the secretion yield of XynBYG by the different signal peptides. The results also suggest that the helical propensity of a signal peptide plays a significant role in the beta-rich xylanase, but not in the helix-rich cutinase, suggesting a coupling of the conformations between the signal peptide and its cargo protein for optimal secretion.