Functional exploration of the glycoside hydrolase family GH113

beta-Mannans are a heterogeneous group of polysaccharides with a common main chain of beta-1,4-linked mannopyranoside residues. The cleavage of beta-mannan chains is catalyzed by glycoside hydrolases called beta-mannanases. In the CAZy database, beta-mannanases are grouped by sequence similarity in families GH5, GH26, GH113 and GH134. Family GH113 has been under-explored so far with six enzymes characterized, all from the Firmicutes phylum. We undertook the functional characterization of 14 enzymes from a selection of 31 covering the diversity of the family GH113. Our observations suggest that GH113 is a family with specificity towards mannans, with variations in the product profiles and modes of action. We were able to assign mannanase and mannosidase activities to four out of the five clades of the family, increasing by 200% the number of characterized GH113 members, and expanding the toolbox for fine-tuning of mannooligosaccharides.

Automated summary

This study focuses on the functional characterization of GH113 family enzymes, revealing their specificity towards mannans with variations in product profiles and modes of action. Four clades of the family were assigned mannanase and mannosidase activities, increasing the number of characterized GH113 members by 200% and expanding the toolbox for fine-tuning of mannooligosaccharides.