Structure-function relationship of the GH168 fucanase reveals an unusual enzyme recognition mechanism for sulfated polysaccharide
Sulfated fucan is one of the most recalcitrant polysaccharides. The molecular mechanism underlying the endo-1,3-fucanase, which plays a critical role in the breakdown of sulfated fucan, remains unexplained. Here, we conduct a comprehensive structure-function relationship investigation on the endo-1,3-fucanases within a family space-GH168. The family can be divided into four subfamilies according to phylogenetic relationship and functional similarities. Subfamily I, Ⅱ and Ⅳ preferentially recognize Fucp2(OSO<sub>3</sub><sup>-</sup>), Fucp2,4(OSO<sub>3</sub><sup>-</sup>) and Fucp units at the +1 subsite, respectively, while consistently recognizing the Fucp2(OSO<sub>3</sub><sup>-</sup>) unit at the -1 subsite. Remarkably, two-thirds of the interacting residues are dedicated to the recognition of sulfate groups along the glycoside chains. This mechanism is distinct from the direct recognition of the sugar backbone employed by neutral polysaccharide hydrolases. These findings unveil a critical enzyme recognition mechanism for sulfate polysaccharides and promote the application of endo-1,3-fucanases in the structural analysis and oligosaccharide production of sulfated fucan.
Authors
- Kaimeng Liu (ORCID: https://orcid.org/0000-0002-7346-1022)
- Changhu Xue (ORCID: https://orcid.org/0000-0002-6976-2906)
- Guangning Chen
- Xuanwei Mei (ORCID: https://orcid.org/0009-0006-1769-5197)
- Yaoguang Chang (ORCID: https://orcid.org/0000-0002-8234-7272)
- Yingang Feng (ORCID: https://orcid.org/0000-0002-0879-1316)
- Fangyi Chen (ORCID: https://orcid.org/0000-0002-5024-6215)
- Yuying Zhang (ORCID: https://orcid.org/0009-0000-0800-1268)
- Ying Sun
- Xinyu Li (ORCID: https://orcid.org/0000-0002-3828-0971)
- Jingjing Shen (ORCID: https://orcid.org/0000-0003-4360-7585)
- Xiaoya Song (ORCID: https://orcid.org/0000-0001-8374-0343)
- Guanchen Liu (ORCID: https://orcid.org/0000-0002-8773-8504)
- Sheng Dong (ORCID: https://orcid.org/0000-0002-0452-5221)
- Menghui Sun
- Achiraya Khamleng
Institutions
- Qingdao University of Science and Technology (CN)
- Kasetsart University (TH)
- Chinese Academy of Sciences (CN)
- Dalian University (CN)
- Qingdao Institute of Marine Geology (CN)
- Department of Fisheries (ZM)
- Marine Biomedical Research Institute of Qingdao (CN)
- Qingdao Institute of Bioenergy and Bioprocess Technology (CN)
- University of Chinese Academy of Sciences (CN)
- BGI Research (CN)
- Ocean University of China (CN)
Publication Details
- Journal
- Nature Communications
- Published
- 2025-10-17
- DOI
- https://doi.org/10.1038/s41467-025-63891-4
- Citations
- 1
- Primary Topic
- Enzyme Production and Characterization
- Type
- article
- Field-Weighted Citation Impact
- 1.23
Funders
- National Natural Science Foundation of China
- Fundamental Research Funds for the Central Universities