Lack of endoplasmic reticulum 1,2-α-mannosidase activity that trims N-glycan Man9GlcNAc2 to Man8GlcNAc2 isomer B in a manE gene disruptant of Aspergillus oryzae.

Abstract The gene manE , encoding a probable class I endoplasmic reticulum 1,2-α-mannosidases (ER-Man), was identified from the filamentous fungus Aspergillus oryzae due to similarity to orthologs. It removes a single mannose residue from Man 9 GlcNAc 2 , generating Man 8 GlcNAc 2 isomer B. Disruption of manE caused drastic decreases in ER-Man activity in A. oryzae microsomes.