8HCJ

Structure of GH43 family enzyme, Xylan 1, 4 Beta- xylosidase from pseudopedobacter saltans

Summary for 8HCJ

• Entry DOI: 10.2210/pdb8hcj/pdb
• Descriptor: Xylan 1,4-beta-xylosidase, CALCIUM ION (3 entities in total)
• Functional Keywords: gh43 family, xylan, xylosidase, hydrolase
• Biological source: Pseudopedobacter saltans DSM 12145
• Total number of polymer chains: 8
• Total formula weight: 407145.43

Authors

Vishwakarma, P.,Sachdeva, E.,Goyal, A.,Ethayathulla, A.S.,Das, U.,Kaur, P. (deposition date: 2022-11-01, release date: 2023-11-15, Last modification date: 2025-01-15)

Primary citation

Vishwakarma, P.,Sachdeva, E.,Thakur, A.,Ethayathulla, A.S.,Goyal, A.,Kaur, P.
Deciphering the structural and biochemical aspects of xylosidase from Pseudopedobacter saltans.
Int.J.Biol.Macromol., 291:139042-139042, 2024

PubMed Abstract: Xylose, a key constituent of the heterogeneous hemicellulose polymer, occurs in lignocellulosic biomass and forms xylan polymers through β-1,4 glycosidic linkages. The β-1,4-xylosidase enzyme was isolated from Pseudopedobacter saltans (PsGH43) to find an effective enzyme with enhanced activity to depolymerize xylo-oligosaccharides. β-1,4-xylosidase belongs to the GH43 family as classified in the Carbohydrate-Active Enzyme Database (CAZy). PsGH43 was found to be active only on xylose-based substrate, 4NPX, with maximum activity occurring at a pH 7 and 30 °C (K 1.96 ± 0.2 mM and V 0.43 mM/min). The study also confirms the influence of Ca ions on enzymatic activity and thermal stability. Subsequently, native PsGH43 was crystallized at optimum conditions and the structure was determined at 2.5 Å resolution. Crystallographic analysis revealed an asymmetric unit containing eight monomers and 16 calcium ions wherein a tetramer constituted the functional unit. Each monomer exhibits a characteristic GH43 N-terminal β-propeller fold that serves as a catalytic domain accommodating one calcium ion in the centre, while the C-terminal β-sandwich fold associated with the CBM6 family preserves another calcium ion. Our study reveals a novel tetrameric arrangement of β-1,4-xylosidase which unravels its functional indispensability. This study opens newer avenues to engineer a potential enzyme for biofuel and bioethanol industry.

PubMed: 39708861
DOI: 10.1016/j.ijbiomac.2024.139042

Experimental method

X-RAY DIFFRACTION (2.566 Å)