Premium
Engineering the N ‐terminal end of CelA results in improved performance and growth of Caldicellulosiruptor bescii on crystalline cellulose
Author(s) -
Kim SunKi,
Chung Daehwan,
Himmel Michael E.,
Bomble Yannick J.,
Westpheling Janet
Publication year - 2017
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.26242
Subject(s) - glycoside hydrolase , chemistry , cellulose , biochemistry , cellulase , catalytic efficiency , enzyme
ABSTRACT CelA is the most abundant enzyme secreted by Caldicellulosiruptor bescii and has been shown to outperform mixtures of commercially available exo‐ and endoglucanases in vitro. CelA contains both a glycoside hydrolase family 9 endoglucanase and a glycoside hydrolase family 48 exoglucanase known to be synergistic in their activity, connected by three cellulose‐binding domains via linker peptides. Here, repeated aspartate residues were introduced into the N ‐terminal ends of CelA GH9 and GH48 domains to improve secretion efficiency and/or catalytic efficiency of CelA. Among several constructs, the highest activity on carboxymethylcellulose (CMC), 0.81 ± 0.03 mg/mL was observed for the C. bescii strain containing CelA with 5‐aspartate tag at the N ‐terminal end of GH9 domain—an 82% increase over wild type CelA. In addition, expression of CelA with N ‐terminal repeated aspartate residues in C. bescii results in a dramatic increase in its ability to grow on Avicel. Biotechnol. Bioeng. 2017;114: 945–950. © 2016 Wiley Periodicals, Inc.