Crystal structure of the Enterococcus faecalis alpha-N-acetylgalactosaminidase, a member of the glycoside hydrolase family 31.
Miyazaki, T., Park, E.Y.(2020) FEBS Lett 594: 2282-2293
- PubMed: 32367553 
- DOI: https://doi.org/10.1002/1873-3468.13804
- Primary Citation of Related Structures:  
6M76, 6M77 - PubMed Abstract: 
Glycoside hydrolases catalyze the hydrolysis of glycosidic linkages in carbohydrates. The glycoside hydrolase family 31 (GH31) contains α-glucosidase, α-xylosidase, α-galactosidase, and α-transglycosylase. Recent work has expanded the diversity of substrate specificity of GH31 enzymes, and α-N-acetylgalactosaminidases (αGalNAcases) belonging to GH31 have been identified in human gut bacteria. Here, we determined the first crystal structure of a truncated form of GH31 αGalNAcase from the human gut bacterium Enterococcus faecalis. The enzyme has a similar fold to other reported GH31 enzymes and an additional fibronectin type 3-like domain. Additionally, the structure in complex with N-acetylgalactosamine reveals that conformations of the active site residues, including its catalytic nucleophile, change to recognize the ligand. Our structural analysis provides insight into the substrate recognition and catalytic mechanism of GH31 αGalNAcases.
Organizational Affiliation: 
Green Chemistry Research Division, Research Institute of Green Science and Technology, Shizuoka University, Japan.