title: Optimal secretion of alkali-tolerant xylanase in Bacillus subtilis by signal peptide screening.
abstract: 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.
authors.affiliation: College of Animal Sciences and Technology, Northwest A&F University, 712100, Yangling, People's Republic of China.
authors.forename: Weiwei
authors.initials: W
authors.lastname: Zhang
authors.affiliation: College of Animal Sciences and Technology, Northwest A&F University, 712100, Yangling, People's Republic of China.
authors.forename: Mingming
authors.initials: M
authors.lastname: Yang
authors.affiliation: Institute for Glycomics and School of Information and Communication Technology, Griffith University, Parklands Dr., Southport, QLD, 4222, Australia.
authors.forename: Yuedong
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Institute for Glycomics and School of Information and Communication Technology, Griffith University, Parklands Dr., Southport, QLD, 4222, Australia.
authors.forename: Jian
authors.initials: J
authors.lastname: Zhan
authors.affiliation: Institute for Glycomics and School of Information and Communication Technology, Griffith University, Parklands Dr., Southport, QLD, 4222, Australia. yaoqi.zhou@griffith.edu.au.
authors.forename: Yaoqi
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: College of Animal Sciences and Technology, Northwest A&F University, 712100, Yangling, People's Republic of China. xin.zhao@mcgill.ca.|Department of Animal Science, McGill University, Quebec, Canada. xin.zhao@mcgill.ca.
authors.forename: Xin
authors.initials: X
authors.lastname: Zhao
mesh_terms: D000069979:Bacillus pumilus / Q000201:enzymology* / Q000235:genetics; D001412:Bacillus subtilis / Q000235:genetics / Q000378:metabolism*; D043364:Endo-1,4-beta Xylanases / Q000032:analysis* / Q000378:metabolism*; D005820:Genetic Testing / Q000379:methods*; D053858:Metabolic Networks and Pathways / Q000235:genetics; D011401:Promoter Regions, Genetic; D021382:Protein Sorting Signals / Q000235:genetics
chemical_list: D021382:Protein Sorting Signals; D043364:Endo-1,4-beta Xylanases
keywords: Alkali-tolerant xylanase; Bacillus subtilis; Partial least squares analysis; Secretion; Signal peptide