8Y0M
beta-glucosidase mutant M279V_T308S_K361R_D433N_N514C
Summary for 8Y0M
| Entry DOI | 10.2210/pdb8y0m/pdb |
| Descriptor | beta-glucosidase, MAGNESIUM ION, 1-DEOXYNOJIRIMYCIN, ... (4 entities in total) |
| Functional Keywords | thermoascus aurantiacus, beta-glucosidase, thermostable enzyme, mutant, hydrolase |
| Biological source | Thermoascus aurantiacus |
| Total number of polymer chains | 4 |
| Total formula weight | 375008.52 |
| Authors | Matsuzaki, C.,Katayama, T. (deposition date: 2024-01-22, release date: 2025-04-30, Last modification date: 2025-11-12) |
| Primary citation | 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 Cited by 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: 39971319DOI: 10.2183/pjab.101.011 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.3 Å) |
Structure validation
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