8I0A

Structure of alpha-L-Arabinofuranosidase from Trametes hirsuta

Summary for 8I0A

• Entry DOI: 10.2210/pdb8i0a/pdb
• Descriptor: alpha-L-arabinofuranosidase (2 entities in total)
• Functional Keywords: glycoside hydrolase 51 family, alpha-l-arabinofuranosidase, hydrolase
• Biological source: Trametes hirsuta
• Total number of polymer chains: 1
• Total formula weight: 60107.49

Authors

Liu, W.,Lu, M.L.,Si, Z.Y.,Han, L. (deposition date: 2023-01-10, release date: 2023-09-27)

Primary citation

Si, Z.,Cai, Y.,Zhao, L.,Han, L.,Wang, F.,Yang, X.,Gao, X.,Lu, M.,Liu, W.
Structure and function characterization of the alpha-L-arabinofuranosidase from the white-rot fungus Trametes hirsuta.
Appl.Microbiol.Biotechnol., 107:3967-3981, 2023

PubMed Abstract: α-L-Arabinofuranosidases (Abfs) play a crucial role in the degradation of hemicelluloses, especially arabinoxylans (AX). Most of the available characterized Abfs are from bacteria, while fungi, as natural decomposers, contain Abfs with little attention given. An arabinofuranosidase (ThAbf1), belonging to the glycoside hydrolase 51 (GH51) family, from the genome of the white-rot fungus Trametes hirsuta, was recombinantly expressed, characterized, and functionally determined. The general biochemical properties showed that the optimal conditions for ThAbf1 were pH 6.0 and 50°C. In substrate kinetics assays, ThAbf1 preferred small fragment arabinoxylo-oligosaccharides (AXOS) and could surprisingly hydrolyze di-substituted 2,3-di-L-arabinofuranosyl-xylotriose (AXX). It also synergized with commercial xylanase (XYL) and increased the saccharification efficiency of arabinoxylan. The crystal structure of ThAbf1 indicated the presence of an adjacent cavity next to the catalytic pocket which led to the ability of ThAbf1 to degrade di-substituted AXOS. The narrow binding pocket prevents ThAbf1 from binding larger substrates. These findings have strengthened our understanding of the catalytic mechanism of GH51 family Abfs and provided a theoretical foundation for the development of more efficient and versatile Abfs to accelerate the degradation and biotransformation of hemicellulose in biomass. KEY POINTS: • ThAbf1 from Trametes hirsuta degraded di-substituted arabinoxylo-oligosaccharide. • ThAbf1 performed detailed biochemical characterization and kinetics. • ThAbf1 structure has been obtained to illustrate the substrate specificity.

PubMed: 37178306
DOI: 10.1007/s00253-023-12561-w

Experimental method

X-RAY DIFFRACTION (2.01 Å)