Carbohydrate-binding domains facilitate efficient oligosaccharides synthesis by enhancing mutant catalytic domain transglycosylation activity

© 2020 Wiley Periodicals LLC..

Chemoenzymatic approaches using carbohydrate-active enzymes (CAZymes) offer a promising avenue for the synthesis of glycans like oligosaccharides. Here, we report a novel chemoenzymatic route for cellodextrins synthesis employed by chimeric CAZymes, akin to native glycosyltransferases, involving the unprecedented participation of a "non-catalytic" lectin-like domain or carbohydrate-binding modules (CBMs) in the catalytic step for glycosidic bond synthesis using β-cellobiosyl donor sugars as activated substrates. CBMs are often thought to play a passive substrate targeting role in enzymatic glycosylation reactions mostly via overcoming substrate diffusion limitations for tethered catalytic domains (CDs) but are not known to participate directly in any nucleophilic substitution mechanisms that impact the actual glycosyl transfer step. This study provides evidence for the direct participation of CBMs in the catalytic reaction step for β-glucan glycosidic bonds synthesis enhancing activity for CBM-based CAZyme chimeras by >140-fold over CDs alone. Dynamic intradomain interactions that facilitate this poorly understood reaction mechanism were further revealed by small-angle X-ray scattering structural analysis along with detailed mutagenesis studies to shed light on our current limited understanding of similar transglycosylation-type reaction mechanisms. In summary, our study provides a novel strategy for engineering similar CBM-based CAZyme chimeras for the synthesis of bespoke oligosaccharides using simple activated sugar monomers.

Medienart:

E-Artikel

Erscheinungsjahr:

2020

Erschienen:

2020

Enthalten in:

Zur Gesamtaufnahme - volume:117

Enthalten in:

Biotechnology and bioengineering - 117(2020), 10 vom: 18. Okt., Seite 2944-2956

Sprache:

Englisch

Beteiligte Personen:

Bandi, Chandra Kanth [VerfasserIn]
Goncalves, Antonio [VerfasserIn]
Pingali, Sai Venkatesh [VerfasserIn]
Chundawat, Shishir P S [VerfasserIn]

Links:

Volltext

Themen:

β-glucan synthase
Bacterial Proteins
Carbohydrate-active enzymes
Carbohydrate-binding modules
CelE protein, bacteria
Cellulase
EC 3.2.1.-
EC 3.2.1.4
Journal Article
Oligosaccharides
Polysaccharides
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.
Transglycosylation

Anmerkungen:

Date Completed 07.10.2021

Date Revised 07.10.2021

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1002/bit.27473

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM311522769