N-terminal catalytic domain of yeast vacuolar alpha-mannosidases and similar proteins; glycoside hydrolase family 38 (GH38)
The family is represented by Saccharomyces cerevisiae alpha-mannosidase (Ams1) and its eukaryotic homologs. Ams1 functions as a second resident vacuolar hydrolase in S. cerevisiae. It aids in recycling macromolecular components of the cell through hydrolysis of terminal, non-reducing alpha-d-mannose residues. Ams1 forms an oligomer in the cytoplasm and retains its oligomeric form during the import process. It utilizes both the Cvt (nutrient-rich conditions) and autophagic (starvation conditions) pathways for biosynthetic delivery to the vacuole. Mutants in either pathway are defective in Ams1 import. Members in this family show high sequence similarity with rat ER/cytosolic alpha-mannosidase Man2C1.