Discovery, structural characterization, and functional insights into a novel apiosidase from the GH140 family, isolated from a lignocellulolytic-enriched mangrove microbial community.
Liberato, M.V., Paixao, D.A.A., Tomazetto, G., Ndeh, D., Bolam, D.N., Squina, F.M.(2024) Biotechnol Lett 46: 201-211
- PubMed: 38280177 
- DOI: https://doi.org/10.1007/s10529-023-03460-1
- Primary Citation of Related Structures:  
8T9W - PubMed Abstract: 
Apiosidases are enzymes that cleave the glycosidic bond between the monosaccharides linked to apiose, a branched chain furanose found in the cell walls of vascular plants and aquatic monocots. There is biotechnological interest in this enzyme group because apiose is the flavor-active compound of grapes, fruit juice, and wine, and the monosaccharide is found to be a plant secondary metabolite with pharmaceutical properties. However, functional and structural studies of this enzyme family are scarce. Recently, a glycoside hydrolase family member GH140 was isolated from Bacteroides thetaiotaomicron and identified as an endo-apiosidase. The structural characterization and functional identification of a second GH140 family enzyme, termed MmApi, discovered through mangrove soil metagenomic approach, are described. Among the various substrates tested, MmApi exhibited activity on an apiose-containing oligosaccharide derived from the pectic polysaccharide rhamnogalacturonan-II. While the crystallographic model of MmApi was similar to the endo-apiosidase from Bacteroides thetaiotaomicron, differences in the shape of the binding sites indicated that MmApi could cleave apioses within oligosaccharides of different compositions. This enzyme represents a novel tool for researchers interested in studying the physiology and structure of plant cell walls and developing biocatalytic strategies for drug and flavor production.
Organizational Affiliation: 
Programa de Processos Tecnológicos e Ambientais, Universidade de Sorocaba, Sorocaba, Brazil.