Crucial Residues of C-Terminal Oligopeptide C60 to Improve the Yield of Prebiotic Xylooligosaccharides by Truncated Mutation
Kungang Pan,
Shanzheng Jin,
Yue Wang,
Zhao Yu,
Junhao Sun,
Tianhui Liu,
Zhengjie Zhang,
Tongcun Zhang,
Zhongyuan Li,
Junqi Zhao
Affiliations
Kungang Pan
Qilu Institute of Technology, School of Chemical and Biological Engineering, Jinan 250200, China
Shanzheng Jin
Key Laboratory of Industrial Fermentation Microbiology of Ministry of Education & Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
Yue Wang
Key Laboratory of Industrial Fermentation Microbiology of Ministry of Education & Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
Zhao Yu
Key Laboratory of Industrial Fermentation Microbiology of Ministry of Education & Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
Junhao Sun
Key Laboratory of Industrial Fermentation Microbiology of Ministry of Education & Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
Tianhui Liu
Key Laboratory of Industrial Fermentation Microbiology of Ministry of Education & Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
Zhengjie Zhang
Key Laboratory of Industrial Fermentation Microbiology of Ministry of Education & Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
Tongcun Zhang
Key Laboratory of Industrial Fermentation Microbiology of Ministry of Education & Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
Zhongyuan Li
Key Laboratory of Industrial Fermentation Microbiology of Ministry of Education & Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
Junqi Zhao
Qilu Institute of Technology, School of Chemical and Biological Engineering, Jinan 250200, China
Increasing the yields of short xylooligosaccharides by enzymatic production is efficient to improve prebiotic effects. Previously, C-terminal oligopeptide C60 was found to accelerate short xylooligosaccharides. Herein, in order to further understand the molecular mechanism of C60, the sequence analysis firstly showed that C60 displays typical properties of a linker (rich in proline/alanine/glycine/glutamine/arginine, 8.33–20.00%). C60 shared the highest identity with the N-terminal region of esterase (98.33%) and high identity with the linker between xylanase and esterase from Prevotella sp. (56.50%), it is speculated to originate from an early linker between XynA and another domain. Besides, structure simulation showed that C60 enhances the molecular interactions between substrate and active residues to improve catalytic efficiency. Moreover, three truncated variants with different lengths of C-terminal regions were successfully generated in Escherichia coli. The specific activities of variants were 6.44–10.24 fold of that of XynA-Tr, and their optimal temperature and pH were the same as XynA-Tr. Three truncated variants released more xylooligosaccharides, especially xylobiose (46.33, 43.41, and 49.60%), than XynA-Tr (32.43%). These results are helpful to understand the molecular mechanism of C60, and also provide new insight to improve the yields of short xylooligosaccharides by molecular modification at the terminal of xylanases.
