Format

Send to

Choose Destination
J Biol Chem. 2018 Nov 23;293(47):18138-18150. doi: 10.1074/jbc.RA118.003302. Epub 2018 Sep 24.

Functional metagenomics identifies an exosialidase with an inverting catalytic mechanism that defines a new glycoside hydrolase family (GH156).

Author information

1
From New England Biolabs, Ipswich, Massachusetts 01938.
2
the Max Planck Institute for Dynamics of Complex Technical Systems, 39106 Magdeburg, Germany.
3
glyXera GmbH, 39120 Magdeburg, Germany.
4
the Architecture et Fonction des Macromolécules Biologiques, CNRS, Aix-Marseille Université, F-13288 Marseille, France.
5
the Institut National de la Recherche Agronomique (INRA), Unité Sous Contrat (USC) 1408, Architecture et Fonction des Macromolécules Biologiques, 13288 Marseille, France, and.
6
the Department of Biological Sciences, King Abdulaziz University, Jeddah 21589, Saudi Arabia.
7
From New England Biolabs, Ipswich, Massachusetts 01938, taron@neb.com.

Abstract

Exosialidases are glycoside hydrolases that remove a single terminal sialic acid residue from oligosaccharides. They are widely distributed in biology, having been found in prokaryotes, eukaryotes, and certain viruses. Most characterized prokaryotic sialidases are from organisms that are pathogenic or commensal with mammals. However, in this study, we used functional metagenomic screening to seek microbial sialidases encoded by environmental DNA isolated from an extreme ecological niche, a thermal spring. Using recombinant expression of potential exosialidase candidates and a fluorogenic sialidase substrate, we discovered an exosialidase having no homology to known sialidases. Phylogenetic analysis indicated that this protein is a member of a small family of bacterial proteins of previously unknown function. Proton NMR revealed that this enzyme functions via an inverting catalytic mechanism, a biochemical property that is distinct from those of known exosialidases. This unique inverting exosialidase defines a new CAZy glycoside hydrolase family we have designated GH156.

KEYWORDS:

extremophile; functional metagenomics; glycoside hydrolase; glycosylation; high-throughput screening (HTS); inverting mechanism; neuraminidase; sialic acid; sialidase

PMID:
30249617
PMCID:
PMC6254351
DOI:
10.1074/jbc.RA118.003302
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for HighWire Icon for PubMed Central
Loading ...
Support Center