IUBMB Enzyme Nomenclature


Accepted name: exo-acting protein-α-N-acetylgalactosaminidase

Reaction: a [protein]N-acetyl-α-D-galactosalaminyl-(L-serine/L-threonine) + H2O = a [protein]-(L-serine/L-threonine) + N-acetyl-D-galactosamine

Other name(s): Nag31

Systematic name: [protein]-N-acetyl-α-D-galactosalaminyl-(L-serine/L-threonine) N-acetylgalactosaminohydrolase

Comments: The enzyme, which belongs to the glycosylhydrolase 31 (GH31) family, is an exo-acting α-N-acetylgalactosaminidase that acts on the innermost α-GalNAc residues at the core of O-glycans when no other saccharides are attached to it. Unlike EC, α-D-acetylgalactosaminidase, it is not able to act on blood group A antigen.


1. Rahfeld, P., Wardman, J.F., Mehr, K., Huff, D., Morgan-Lang, C., Chen, H.M., Hallam, S.J. and Withers, S.G. Prospecting for microbial α-N-acetylgalactosaminidases yields a new class of GH31 O-glycanase. J. Biol. Chem. 294 (2019) 16400-16415. [PMID: 31530641]

2. Miyazaki, T. and Park, E.Y. Crystal structure of the Enterococcus faecalis α-N-acetylgalactosaminidase, a member of the glycoside hydrolase family 31. FEBS Lett. 594 (2020) 2282–2293. [PMID: 32367553]

3. Ikegaya, M., Miyazaki, T. and Park, E.Y. Biochemical characterization of Bombyx mori α-N-acetylgalactosaminidase belonging to the glycoside hydrolase family 31. nsect Mol Biol. 30 (2021) 367–378. [PMID: 33742736]

4. Miyazaki, T., Ikegaya, M. and Alonso-Gil, S. Structural and mechanistic insights into the substrate specificity and hydrolysis of GH31 α-N-acetylgalactosaminidase. Biochimie (2021) . [PMID: 34826537]

[EC created 2022]

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