Catalytic efficiency of a multi-domain transglycosylating chitinase from Enterobacter cloacae subsp. cloacae (EcChi2) is influenced by polycystic kidney disease domains.
Chitinase
Chitooligosaccharides
EcChi2
EcChi2 variants
Transglycosylation
Journal
Enzyme and microbial technology
ISSN: 1879-0909
Titre abrégé: Enzyme Microb Technol
Pays: United States
ID NLM: 8003761
Informations de publication
Date de publication:
Feb 2021
Feb 2021
Historique:
received:
27
06
2020
revised:
30
10
2020
accepted:
05
11
2020
entrez:
30
12
2020
pubmed:
31
12
2020
medline:
19
8
2021
Statut:
ppublish
Résumé
Bacterial chitinases recruited multiple accessory domains for the conversion of recalcitrant polysaccharides to simple soluble sugars/amino sugars. Here, we report detailed properties of a multi-domain GH18 chitinase from Enterobacter cloacae subsp. cloacae (EcChi2) that preferred β-chitin as substrate. EcChi2 exhibited transglycosylation (TG) activity on oligomeric substrates from DP4-DP6. The high amount of DP2 is indicative of exo mode activity of EcChi2. We generated EcChi2 variants (truncated and fusion chimeras) and elucidated the role of catalytic and accessory domains. The catalytic efficiency of truncated GH18 and fusion chimera of GH18+ChBD1-ChBD2 decreased to 22 and 17-fold, respectively, than EcChi2, and lost the hydrolytic activity on polymeric substrates, except colloidal chitin. On the other hand, the catalytic activity of truncated PKD1-GH18-PKD2 on polymeric and oligomeric substrates was similar to EcChi2, suggesting that PKD domains are essential for increasing the rate of hydrolysis. Moreover, the truncated ChBD1-ChBD2 and fusion PKD1 + PKD2 participated in chitin-binding.
Identifiants
pubmed: 33375970
pii: S0141-0229(20)30195-2
doi: 10.1016/j.enzmictec.2020.109702
pii:
doi:
Substances chimiques
Chitin
1398-61-4
Chitinases
EC 3.2.1.14
Types de publication
Journal Article
Langues
eng
Sous-ensembles de citation
IM
Pagination
109702Informations de copyright
Copyright © 2020 Elsevier Inc. All rights reserved.