8Y0M

beta-glucosidase mutant M279V_T308S_K361R_D433N_N514C

8Y0M の概要

• エントリーDOI: 10.2210/pdb8y0m/pdb
• 分子名称: beta-glucosidase, MAGNESIUM ION, 1-DEOXYNOJIRIMYCIN, ... (4 entities in total)
• 機能のキーワード: thermoascus aurantiacus, beta-glucosidase, thermostable enzyme, mutant, hydrolase
• 由来する生物種: Thermoascus aurantiacus
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 375008.52

構造登録者

Matsuzaki, C.,Katayama, T. (登録日: 2024-01-22, 公開日: 2025-04-30, 最終更新日: 2025-11-12)

主引用文献

Matsuzaki, C.,Hidaka, M.,Nakashima, Y.,Honda, Y.,Koyanagi, T.,Ishikawa, K.,Katoh, T.,Katayama, T.,Kumagai, H.
A thermostable and highly active fungal GH3 beta-glucosidase generated by random and saturation mutagenesis.
Proc Jpn Acad Ser B Phys Biol Sci, 101:177-195, 2025

PubMed Abstract: Enhancing the thermostability of cellulose-degrading enzymes is pivotal for establishing an efficient bioconversion system from cellulosic materials to value-added compounds. Here, by introducing random and saturation mutagenesis into the Thermoascus aurantiacus β-glucosidase gene, we generated a hyperthermostable mutant with five amino acid substitutions. Analysis of temperature-induced unfolding revealed the involvement of each replacement in the increased T value. Structural analysis showed that all replacements are located at the periphery of the catalytic pocket. D433N replacement, which had a pronounced thermostabilizing effect (ΔT ＝ 4.5°C), introduced an additional hydrogen bond with a backbone carbonyl oxygen in a long loop structure. The mutant enzyme expressed in Kluyveromyces marxianus exhibited a T of 82°C and hydrolyzed cellobiose with k and K values of 200 s and 1.8 mM, respectively. When combined with a thermostable endoglucanase, the mutant enzyme released 20％ more glucose than wild-type enzyme from cellulosic material. The mutant enzyme is therefore a noteworthy addition to the existing repertoire of thermostable β-glucosidases.

PubMed: 39971319
DOI: 10.2183/pjab.101.011

実験手法

X-RAY DIFFRACTION (2.3 Å)