A broad-spectrum family GH13 α-glucosidase from Marinovum sp., a member of the Roseobacter clade

Li, J.; Mui, J. W.- Y.; da Silva, B. M.; Pires, D. E. V.; Ascher, D. B.; Madiedo Soler, N.; Goddard-Borger, E. D.; Williams, S. J.

doi:10.1101/2023.03.31.535182

bioRxiv · 10.1101/2023.03.31.535182

A broad-spectrum family GH13 α-glucosidase from Marinovum sp., a member of the Roseobacter clade

Li, J.·Mui, J. W.- Y.·da Silva, B. M.·Pires, D. E. V.·Ascher, D. B.·Madiedo Soler, N.·Goddard-Borger, E. D.·Williams, S. J.

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Abstract

Glycoside hydrolases (GHs) are a diverse group of enzymes that catalyze the hydrolysis of glycosidic bonds. The Carbohydrate-Active enZymes (CAZy) classification organizes GHs into families based on sequence data and function, with fewer than 1% of the predicted proteins characterized biochemically. Consideration of genomic context can provide clues to infer possible enzyme activities for proteins of unknown function. We used the MultiGeneBLAST tool to discover a gene cluster in Marinovum sp., a member of the marine Roseobacter clade, that encodes homologues of enzymes belonging to the sulfoquinovose monooxygenase pathway for sulfosugar catabolism. This cluster lacks a gene encoding a classical family GH31 sulfoquinovosidase candidate, but which instead includes an uncharacterized family GH13 protein (MsGH13) that we hypothesized could be a non-classical sulfoquinovosidase. Surprisingly, recombinant MsGH13 lacks sulfoquinovosidase activity and is a broad spectrum -glucosidase that is active on a diverse array of -linked disaccharides, including: maltose, sucrose, nigerose, trehalose, isomaltose, and kojibiose. Using AlphaFold, a 3D model for the MsGH13 enzyme was constructed that predicted its active site shared close similarity with an -glucosidase from Halomonas sp. H11 of the same GH13 subfamily that shows narrower substrate specificity.

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Li, J., Mui, J. W.- Y., da Silva, B. M., Pires, D. E. V., Ascher, D. B., Madiedo Soler, N., Goddard-Borger, E. D., Williams, S. J.. 2023-04-01. A broad-spectrum family GH13 α-glucosidase from Marinovum sp., a member of the Roseobacter clade. https://doi.org/10.1101/2023.03.31.535182

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