Reaction: Hydrolysis of (1→4)-β-D-GlcNAc residues from the reducing end of oligosaccharides (GlcNAc)n → (GlcNAc)n-1 + GlcNAc
Other name(s): reducing-end GlcNAc-releasing chitin oligosaccharide hydrolase; MoChia1
Systematic name: N-acetyl-β-D-glucosaminyl-(1→4)-N-acetyl-β-D-glucosamine reducing-end N-acetyl-β-D-glucosaminohydrolase
Comments: The enzyme, originally isolated from the bacterium Pyricularia oryzae, specifically recognizes the reducing end β-anomer of chitin oligosaccharides with a degree of polymerization of at least 3 [(GlcNAc)n (n≥3)] and releases the terminal GlcNAc unit, leaving the new reducing end in the β configuration. It has barely detectable activity toward chitin polymer. This enzyme is distinct from exo-chitinase (reducing end) (EC 3.2.1.201), which releases disaccharide unit from the reduing end of chitin and chitodextrins (chitin oligosaccharides). cf. EC 3.2.1.202, endo-chitodextrinase.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Ohnuma, T., Imaoka, S., Kataoka, C., Yoshimoto, T., Okada, R., Takeda, T., Fukamizo, T., Sakuda, S. and Ogata, M. MoChia1 is a GH18 reducing-end GlcNAc-releasing chitin oligosaccharide hydrolase from the rice blast fungus Magnaporthe oryzae. J. Biol. Chem. 302 (2026) 111462. [PMID: 41999891]