9UPT

Structure of AtBgl1A, a GH1 beta-Glucosidase from Acetivibrio thermocellus

Summary for 9UPT

• Entry DOI: 10.2210/pdb9upt/pdb
• Descriptor: Beta-glucosidase A, GLYCEROL (3 entities in total)
• Functional Keywords: beta-glucosidase, gh1, acetivibrio thermocellus, hydrolase
• Biological source: Acetivibrio thermocellus ATCC 27405
• Total number of polymer chains: 1
• Total formula weight: 53941.78

Authors

Pitchayatanakorn, P.,Kongsaeree, P.T.,Kongsaeree, P. (deposition date: 2025-04-29, release date: 2025-07-02, Last modification date: 2025-07-23)

Primary citation

Pitchayatanakorn, P.,Putthasang, P.,Chomngam, S.,Jongkon, N.,Choowongkomon, K.,Kongsaeree, P.,Fushinobu, S.,Kongsaeree, P.T.
Structure-Based Engineering to Improve Thermostability of At Bgl1A beta ‐Glucosidase.
Acs Omega, 10:27153-27164, 2025

PubMed Abstract: β-Glucosidases are essential enzymes in cellulose degradation and hold significant promise for industrial applications, particularly in biorefinery processes. This study focused on the structural and functional characterization of Bgl1A, a glycoside hydrolase family 1 β-glucosidase from , and its rational engineering to enhance thermostability. Bgl1A exhibited over 400-fold higher specificity for laminaribiose than cellobiose, supporting its physiological role in laminaribiose metabolism. The crystal structure of the wild-type Bgl1A was determined at 2.37-Å resolution, and served as a guide for the design of thermostabilizing mutations. Among variants, the A17S/S39T/T105V triple mutant showed the most significant improvement in thermostability, with a 145 min increase in half-life at 70 and a 5.6 °C elevation in inactivation temperature, while retaining comparable kinetic efficiency. This mutant also outperformed both the wild-type Bgl1A and commercial enzyme in hydrolyzing cellulose and laminaran at both 60 and 70 °C. Molecular dynamics simulations and residue interaction analyses suggested that the enhanced thermostability was associated with additional hydrogen bonds, van der Waals contacts, and hydrophobic interactions introduced by the mutations. These findings provide valuable insights into the structural determinants of thermostability in GH1 β-glucosidases and demonstrate the potential of rational protein engineering for developing robust biocatalysts for industrial biomass conversion.

PubMed: 40621033
DOI: 10.1021/acsomega.5c02381

Experimental method

X-RAY DIFFRACTION (2.369 Å)