Extending the linker region increases the activity of the Bacillus subtilis cellulase CelI15.
OBJECTIVE
To investigate the effect of the linker region (LR) on the enzymatic activity, stability, and flexibility of Bacillus subtilis cellulase CelI15, six mutants were constructed that contained increasing numbers of the LR.


RESULTS
The CelI15 mutant with three copies of the LR (approx. 57 amino acids) showed the highest activity, which was almost 20 % greater than that of wild type CelI15. The stability of the mutant enzymes increased as the copy number of the LR decreased. However, the substrate affinity of the mutant enzymes increased as the LR copy number increased, and the mutant with four copies of the LR exhibited the highest substrate affinity. Additionally, the flexibility of the CelI15 mutants increased as the LR copy number increased from zero to four copies, although it decreased sharply for the mutant with five copies of the LR.


CONCLUSIONS
The activity of CelI15 was increased by increasing the LR copy number, which could be a potential way to improve its enzymatic properties.
School of Life Science, Zhengzhou University, 100 Kexue Street, Zhengzhou, 450001, China.
Pingping
P
Li
School of Life Science, Zhengzhou University, 100 Kexue Street, Zhengzhou, 450001, China.
Yang
Y
Zhou
School of Life Science, Zhengzhou University, 100 Kexue Street, Zhengzhou, 450001, China.
Qian
Q
Li
School of Life Science, Zhengzhou University, 100 Kexue Street, Zhengzhou, 450001, China.
Chong
C
Zhang
School of Life Science, Zhengzhou University, 100 Kexue Street, Zhengzhou, 450001, China.
Zhaowei
Z
Sun
School of Life Science, Zhengzhou University, 100 Kexue Street, Zhengzhou, 450001, China.
Liuyang
L
Tian
School of Life Science, Zhengzhou University, 100 Kexue Street, Zhengzhou, 450001, China. whb@zzu.edu.cn.
Haibo
H
Weng
D001412:Bacillus subtilis / Q000201:enzymology*; D002480:Cellulase / Q000235:genetics / Q000378:metabolism*; D009154:Mutation
D002480:Cellulase
Bacillus subtilis strain I15; Cellulase; Linker region (LR)