7EZT

The structure and functional mechanism of nucleotide regulated acetylhexosaminidase Am2136 from Akkermansia muciniphila

Summary for 7EZT

• Entry DOI: 10.2210/pdb7ezt/pdb
• Descriptor: Beta-N-acetylhexosaminidase, MAGNESIUM ION, ... (6 entities in total)
• Functional Keywords: akkermansia muciniphila glycosidase mucin, hydrolase
• Biological source: Akkermansia muciniphila (strain ATCC BAA-835 / Muc); More
• Total number of polymer chains: 4
• Total formula weight: 329090.40

Authors

Bao, R.,Li, C.C.,Tang, X.Y.,Zhu, Y.B.,Song, Y.J.,Zhao, N.L.,Huang, Q.,Mou, X.Y.,Luo, G.H.,Liu, T.G. (deposition date: 2021-06-02, release date: 2022-11-02, Last modification date: 2024-10-16)

Primary citation

Li, C.C.,Yi, H.,Wang, Y.M.,Tang, X.Y.,Zhu, Y.B.,Song, Y.J.,Zhao, N.L.,Huang, Q.,Mou, X.Y.,Luo, G.H.,Liu, T.G.,Yang, G.L.,Zeng, Y.J.,Wang, L.J.,Tang, H.,Fan, G.,Bao, R.
Nucleotide binding as an allosteric regulatory mechanism for Akkermansia muciniphila beta- N -acetylhexosaminidase Am2136.
Gut Microbes, 14:2143221-2143221, 2022

PubMed Abstract: β--acetylhexosaminidases (EC3.2.1.52), which belong to the glycosyl hydrolase family GH20, are important enzymes for oligosaccharides modification. Numerous microbial β--acetylhexosaminidases have been investigated for applications in biology, biomedicine and biotechnology. is an anaerobic intestinal commensal bacterium which possesses specific β--acetylhexosaminidases for gut mucosal layer colonization and mucin degradation. In this study, we assessed the in vitro mucin glycan cleavage activity of the β--acetylhexosaminidase Am2136 and demonstrated its ability that hydrolyzing the β-linkages joining -acetylglucosamine to a wide variety of aglycone residues, which indicated that Am2136 may be a generalist β--acetylhexosaminidase. Structural and enzyme activity assay experiments allowed us to probe the essential function of the inter-domain interactions in β23-β33. Importantly, we revealed that the hydrolysis activity of Am2136 was enhanced by nucleotides. We further speculated that this activation mechanism might be associated with the conformational motions between domain III and IV. To our knowledge, this is the first report of nucleotide effector regulated β--acetylhexosaminidase, to reveal its novel biological functions. These findings contribute to understanding the distinct properties within the GH20 family and lay a certain foundation to develop controllable glycan hydrolyzing catalysts.: OD600 - optical cell densities at 600 nm; LB - Luria-Bertani; IPTG - isopropyl β-D-1-thiogalactopyranoside; PMSF - phenylmethanesulfonyl fluoride; rmsd - root mean square deviation; GlcNAc - N-acetyl-β-D-glucosamine; GalNAc - N-acetyl-β-D-galactosamine; Gal - galactose.

PubMed: 36394293
DOI: 10.1080/19490976.2022.2143221

Experimental method

X-RAY DIFFRACTION (2.81 Å)