Background <p>The discovery of novel biocatalysts for the sustainable valorization of complex biomass feedstocks remains a significant challenge. Domain-centric exploration of characterized CAZyme families offers a promising but underexplored strategy for identifying enzymes with unusual architectures and potentially expanded substrate specificities.</p> Results <p>Systematic analysis of archaeal glycoside hydrolase family 18 (GH18) chitinases using the CANDy domain annotation pipeline led to the identification of <i>Tc</i>Chi from <i>Thermococcus chitonophagus</i>, a multidomain enzyme combining a GH12 and a GH18 catalytic domain alongside two carbohydrate-binding modules. Given that <i>T. chitonophagus</i> also encodes dedicated standalone cellulases and chitinases, we hypothesized that this multidomain assembly may have evolved a broader functional range than either composing domain alone. Biochemical assays of truncated constructs confirmed this hypothesis: the GH18 domain hydrolyzed chitin, chitosan, and β-1,3-glucan, marking the first report of β-1,3-glucanase activity (EC 3.2.1.58) in a GH18 chitinase, while the GH12 domain exhibited strong cellulase activity alongside unexpected chitosanase activity (EC 3.2.1.132), extending the known functional range of this family. Both domains demonstrated high thermostability consistent with the hyperthermophilic origin of <i>T. chitonophagus</i>.</p> Conclusions <p><i>Tc</i>Chi is a thermostable, multifunctional biocatalyst capable of degrading chitin, chitosan, cellulose, and β-1,3-glucan from a single protein scaffold, making it a promising candidate for consolidated biomass deconstruction and waste valorization. These findings also demonstrate that domain-centric analysis of CAZyme families is an effective strategy for uncovering hidden functional diversity in well-characterized enzyme families.</p>

错误:搜索内容不能为空,请输入英文关键词
错误:关键词超出字数限制,请精简
高级检索

Discovery of a multifunctional chitinase–cellulase from Thermococcus chitonophagus with expanded polysaccharide specificity

  • Alex Windels,
  • Shari Dhaene,
  • Tom Desmet

摘要

Background

The discovery of novel biocatalysts for the sustainable valorization of complex biomass feedstocks remains a significant challenge. Domain-centric exploration of characterized CAZyme families offers a promising but underexplored strategy for identifying enzymes with unusual architectures and potentially expanded substrate specificities.

Results

Systematic analysis of archaeal glycoside hydrolase family 18 (GH18) chitinases using the CANDy domain annotation pipeline led to the identification of TcChi from Thermococcus chitonophagus, a multidomain enzyme combining a GH12 and a GH18 catalytic domain alongside two carbohydrate-binding modules. Given that T. chitonophagus also encodes dedicated standalone cellulases and chitinases, we hypothesized that this multidomain assembly may have evolved a broader functional range than either composing domain alone. Biochemical assays of truncated constructs confirmed this hypothesis: the GH18 domain hydrolyzed chitin, chitosan, and β-1,3-glucan, marking the first report of β-1,3-glucanase activity (EC 3.2.1.58) in a GH18 chitinase, while the GH12 domain exhibited strong cellulase activity alongside unexpected chitosanase activity (EC 3.2.1.132), extending the known functional range of this family. Both domains demonstrated high thermostability consistent with the hyperthermophilic origin of T. chitonophagus.

Conclusions

TcChi is a thermostable, multifunctional biocatalyst capable of degrading chitin, chitosan, cellulose, and β-1,3-glucan from a single protein scaffold, making it a promising candidate for consolidated biomass deconstruction and waste valorization. These findings also demonstrate that domain-centric analysis of CAZyme families is an effective strategy for uncovering hidden functional diversity in well-characterized enzyme families.