6IER

Apo structure of a beta-glucosidase 1317

Summary for 6IER

• Entry DOI: 10.2210/pdb6ier/pdb
• Descriptor: beta-glucosidase 1317, 2-AMINO-2-HYDROXYMETHYL-PROPANE-1,3-DIOL (3 entities in total)
• Functional Keywords: beta-glucosidase, glucose tolerance, substrate specificity, hydrolase
• Biological source: uncultured bacterium
• Total number of polymer chains: 1
• Total formula weight: 48916.08

Authors

Xie, W.,Liu, X. (deposition date: 2018-09-16, release date: 2019-07-24, Last modification date: 2023-11-22)

Primary citation

Liu, X.,Cao, L.,Zeng, J.,Liu, Y.,Xie, W.
Improving the cellobiose-hydrolysis activity and glucose-tolerance of a thermostable beta-glucosidase through rational design.
Int.J.Biol.Macromol., 136:1052-1059, 2019

PubMed Abstract: β-Glucosidase is the rate-limiting component of a cellulase-hydrolyzing reaction. Thermostability and glucose-tolerance are two critical criteria of the enzyme, which practically determine its performance in industrial applications. In this study, a thermostable and glucose-tolerant β-glucosidase (named Bgl1317) belonging to the glycoside hydrolase family 1 was acquired from a metagenomic library of Turpan soil through functional screening. Bgl1317 showed excellent thermostability and glucose-tolerance and its crystal structure was subsequently determined at a high resolution. Rational design based on the structure was conducted, producing three beneficial mutations A397R, L188A and A262S. While A397R improved the cellobiose activity by 80%, L188A and A262S increased the IC value of glucose from 0.8 to 1.5 M. The residues that may play a role in glucose-tolerance of GH1 β-glucosidases were summarized and the performances of glucose-tolerant β-glucosidases reported in recent years were discussed and compared. This study provides insights into enzymatic properties of Bgl1317 for engineering it into a powerful catalyst and β-glucosidases in general.

PubMed: 31199970
DOI: 10.1016/j.ijbiomac.2019.06.029

Experimental method

X-RAY DIFFRACTION (2.246 Å)