Elucidation of the catalytic mechanism of bacterial cell-surface-expressed chitinase ChiW and chitin oligosaccharide production by using the high transglycosylation activity of ChiW.

2015 Fiscal Year Final Research Report

• Project/Area Number: 25850234
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Environmental agriculture(including landscape science)
• Research Institution: Fukui Prefectural University
• Principal Investigator: Itoh Takafumi 福井県立大学, 生物資源学部, 准教授 (10402827)
• Research Collaborator: HIBI Takao 福井県立大学, 生物資源学部, 教授 (00285181) ; KIMOTO Hisashi 福井県立大学, 生物資源学部, 教授 (70283166) ; FUJII Yutaka 福井大学, 医学部, 教授 (80211522)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: Chitinase / Paenibacillus / Structural biology / chitin oligosaccharides

Outline of Final Research Achievements

The purposes of this study are to elucidate the degradation mechanism of the novel multi-modular surface-expressed chitinase, ChiW, of Paenibacillus sp. str. FPU-7 and to enhance the transglycosylation activity of the enzyme.
(1) The degradation mechanism of ChiW. The crystal structure of ChiW was determined at 2.0 angstrom resolution. The structural and functional analyses reveal that the enzyme is composed of six structural domains for efficient chitin degradation. (2) Enhancement of the transglycosylation activity of ChiW. The important residues for substrate binding were selected as the mutation sites. The mutant enzymes were prepared by site-specific mutagenesis. As the result, two mutant enzymes with higher transglycosylation activities (120-130%) were obtained. (3) Identification of P. FPU-7 proteins for chitin degradation. Proteomic analysis was carried on P. FPU-7 extracellular proteins. A number of chitinase and chitin-related proteins were identified thorough the analysis.

Free Research Field

構造生物学