Deletion analysis of regions at the C-terminal part of cycloisomaltooligosaccharide glucanotransferase from Bacillus circulans T-3040

Cited 16 time in scopus
Metadata Downloads
Title
Deletion analysis of regions at the C-terminal part of cycloisomaltooligosaccharide glucanotransferase from Bacillus circulans T-3040
Author(s)
K Funane; Y Kawabata; R Suzuki; Young Min Kim; H K Kang; N Suzuki; Z Fujimoto; A Kimura; M Kobayashi
Bibliographic Citation
Biochimica et Biophysica Acta-Proteins and Proteomics, vol. 1814, no. 3, pp. 428-434
Publication Year
2011
Abstract
Cycloisomaltooligosaccharide glucanotransferase (CITase) belongs to glycoside hydrolase family 66. According to the sequence alignment of enzymes in the same family, we divided the structure of CITase into five regions from the N terminus to the C terminus: an N-terminal conserved region (Ser1-Gly403), an insertion region (R1; Tyr404-Tyr492), two conserved regions (R2; Glu493-Ser596 and R3; Gly597-Met700), and a C-terminal variable region (R4; Lys701-Ser934). CITase catalyzes the synthesis of cycloisomaltooligosaccharides (CIs) with 7-17 glucose units (CI-7 to CI-17) from dextran. In order to clarify the functions of these C-terminal regions (R1-R4), we constructed 15 deletion mutant enzymes. M123Δ (R4-deleted), MΔ234 (R1-deleted), and MΔ23Δ (R1/R4-deleted) catalyzed CI synthesis, but other mutants were inactive. M123Δ, MΔ234, and MΔ23Δ increased their Km values against dextran 40. The wild-type enzyme and M123Δ produced CI-8 predominantly, but MΔ234 and MΔ23Δ lost CI-8 production specificity. The kcat values of MΔ234 and MΔ23Δ decreased, and these mutants showed narrowed temperature and pH stability ranges. Our deletion analysis suggests that (i) R2 and R3 are crucial for CITase to generate an active form; (ii) both R1 and R4 contribute to substrate binding; and (iii) R1 also contributes to preference of CI-8 production and enzyme stability.
Keyword
Bacillus circulansC-terminal regionCyclodextranCycloisomaltooligosaccharideCycloisomaltooligosaccharide glucanotransferase
ISSN
1570-9639
Publisher
Elsevier
DOI
http://dx.doi.org/10.1016/j.bbapap.2010.12.009
Type
Article
Appears in Collections:
1. Journal Articles > Journal Articles
Files in This Item:
  • There are no files associated with this item.


Items in OpenAccess@KRIBB are protected by copyright, with all rights reserved, unless otherwise indicated.