A highly conserved aspartic acid residue of the chitosanase from Bacillus sp. TS is involved in the substrate binding

Zhanping Zhou, Shuangzhi Zhao, Yang Liu, Zhengying Chang, Yanhe Ma, Jian Li, Jiangning Song

Research output: Contribution to journalArticleResearchpeer-review

Abstract

The chitosanase from Bacillus sp. TS (CsnTS) is an enzyme belonging to the glycoside hydrolase family 8. The sequence of CsnTS shares 98 % identity with the chitosanase from Bacillus sp. K17. Crystallography analysis and site-direct mutagenesis of the chitosanase from Bacillus sp. K17 identified the important residues involved in the catalytic interaction and substrate binding. However, despite progress in understanding the catalytic mechanism of the chitosanase from the family GH8, the functional roles of some residues that are highly conserved throughout this family have not been fully elucidated. This study focused on one of these residues, i.e., the aspartic acid residue at position 318. We found that apart from asparagine, mutation of Asp318 resulted in significant loss of enzyme activity. In-depth investigations showed that mutation of this residue not only impaired enzymatic activity but also affected substrate binding. Taken together, our results showed that Asp318 plays an important role in CsnTS activity.

Original languageEnglish
Pages (from-to)1167-1179
Number of pages13
JournalApplied Biochemistry and Biotechnology - Part A Enzyme Engineering and Biotechnology
Volume180
Issue number6
DOIs
Publication statusPublished - 1 Nov 2016

Keywords

  • Aspartic acid
  • Chitosanase
  • Enzyme-substrate interaction
  • Glycoside hydrolase family 8

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