8HUI

Crystal structure of DFA I-forming Inulin Lyase from Streptomyces peucetius subsp. caesius ATCC 27952 in complex with GF4, DFA I, and fructose

Summary for 8HUI

• Entry DOI: 10.2210/pdb8hui/pdb
• Descriptor: Fructotransferase, beta-D-fructofuranose-(2-1)-alpha-D-fructofuranose, beta-D-fructofuranose-(2-1)-beta-D-fructofuranose-(2-1)-beta-D-fructofuranose-(2-1)-beta-D-fructofuranose-(2-1)-alpha-D-glucopyranose, ... (8 entities in total)
• Functional Keywords: right-handed beta-helix protein, dfa i-forming inulin lyase, complex, lyase
• Biological source: Streptomyces peucetius subsp. caesius ATCC 27952
• Total number of polymer chains: 3
• Total formula weight: 132800.60

Authors

Cheng, M.,Rao, Y.J.,Mu, W.M. (deposition date: 2022-12-24, release date: 2023-12-27, Last modification date: 2025-01-08)

Primary citation

Cheng, M.,Hou, X.,Huang, Z.,Chen, Z.,Ni, D.,Zhang, W.,Rao, Y.,Mu, W.
Structural Insights into the Catalytic Cycle of Inulin Fructotransferase: From Substrate Anchoring to Product Releasing.
J.Agric.Food Chem., 72:17030-17040, 2024

PubMed Abstract: Carbohydrate degradation is crucial for living organisms due to their essential functions in providing energy and composing various metabolic pathways. Nevertheless, in the catalytic cycle of polysaccharide degradation, the details of how the substrates bind and how the products release need more case studies. Here, we choose an inulin fructotransferase (IFTase) as a model system, which can degrade inulin into functionally difructose anhydride I. At first, the crystal structures of IFTase in the absence of carbohydrates and complex with fructosyl-nystose (GF4), difructose anhydride I, and fructose are obtained, giving the substrate trajectory and product path of IFTase, which are further supported by steered molecular dynamics simulations (MDSs) along with mutagenesis. Furthermore, structural topology variations at the active centers of inulin fructotransferases are suggested as the structural base for product release, subsequently proven by substitution mutagenesis and MDSs. Therefore, this study provides a case in point for a deep understanding of the catalytic cycle with substrate trajectory and product path.

PubMed: 39034843
DOI: 10.1021/acs.jafc.4c03615

Experimental method

X-RAY DIFFRACTION (1.44 Å)