Engineering mesophilic GH11 xylanase from Cellulomonas flavigena by rational design of N-terminus substitution

Wenzhuo Tian; Ziyang Zhang; Cuiping Yang; Piwu Li; Jing Xiao; Ruiming Wang; Peng Du; Nan Li; Junqing Wang

doi:10.3389/fbioe.2022.1044291

Engineering mesophilic GH11 xylanase from Cellulomonas flavigena by rational design of N-terminus substitution

Front Bioeng Biotechnol. 2022 Nov 3:10:1044291. doi: 10.3389/fbioe.2022.1044291. eCollection 2022.

Authors

Wenzhuo Tian^{1

2}, Ziyang Zhang², Cuiping Yang², Piwu Li^{1

2}, Jing Xiao^{1

2}, Ruiming Wang^{1

2}, Peng Du^{1

2}, Nan Li^{1

2}, Junqing Wang^{1

2}

Affiliations

¹ State Key Laboratory of Biobased Material and Green Papermaking (LBMP) (Qilu University of Technology), Jinan, China.
² School of Biological Engineering, Qilu University of Technology, Jinan, China.

Abstract

Xylanase, a glycoside hydrolase, is widely used in the food, papermaking, and textile industries; however, most xylanases are inactive at high temperatures. In this study, a xylanase gene, CFXyl3, was cloned from Cellulomonas flavigena and expressed in Escherichia coli BL21 (DE3). To improve the thermostability of xylanase, four hybrid xylanases with enhanced thermostability (designated EcsXyl1-4) were engineered from CFXyl3, guided by primary and 3D structure analyses. The optimal temperature of CFXyl3 was improved by replacing its N-terminus with the corresponding area of SyXyn11P, a xylanase that belongs to the hyperthermostable GH11 family. The optimal temperatures of the hybrid xylanases EcsXyl1-4 were 60, 60, 65, and 85°C, respectively. The optimal temperature of EcsXyl4 was 30 C higher than that of CFXyl3 (55°C) and its melting temperature was 34.5°C higher than that of CFXyl3. After the hydrolysis of beechwood xylan, the main hydrolysates were xylotetraose, xylotriose, and xylobiose; thus, these hybrid xylanases could be applied to prebiotic xylooligosaccharide manufacturing.

Keywords: Cellulomonas flavigena; N-terminus substitution; glycoside hydrolase family 11; thermostability; xylanase.