8I2R

Beijerinckia indica beta-fructosyltransferase variant H395R/F473Y in complex with fructose

Summary for 8I2R

• Entry DOI: 10.2210/pdb8i2r/pdb
• Descriptor: Beta-fructosyltransferase, MAGNESIUM ION, beta-D-fructofuranose, ... (5 entities in total)
• Functional Keywords: beta-fructosyltransferase, hydrolase, transferase
• Biological source: Beijerinckia indica subsp. indica NBRC 3744
• Total number of polymer chains: 1
• Total formula weight: 57628.92

Authors

Tonozuka, T. (deposition date: 2023-01-15, release date: 2023-06-14, Last modification date: 2024-10-16)

Primary citation

Li, D.,Miyasaka, Y.,Kubota, A.,Kozono, T.,Kitano, Y.,Sasaki, N.,Fujii, T.,Tochio, T.,Kadota, Y.,Nishikawa, A.,Tonozuka, T.
Characterization and alteration of product specificity of Beijerinckia indica subsp. indica beta-fructosyltransferase.
Biosci.Biotechnol.Biochem., 87:981-990, 2023

PubMed Abstract: The trisaccharide 1-kestose, a major constituent of fructooligosaccharide, has strong prebiotic effects. We used high-performance liquid chromatography and 1H nuclear magnetic resonance spectroscopy to show that BiBftA, a β-fructosyltransferase belonging to glycoside hydrolase family 68, from Beijerinckia indica subsp. indica catalyzes transfructosylation of sucrose to produce mostly 1-kestose and levan polysaccharides. We substituted His395 and Phe473 in BiBftA with Arg and Tyr, respectively, and analyzed the reactions of the mutant enzymes with 180 g/L sucrose. The ratio of the molar concentrations of glucose and 1-kestose in the reaction mixture with wild-type BiBftA was 100:8.1, whereas that in the reaction mixture with the variant H395R/F473Y was 100:45.5, indicating that H395R/F473Y predominantly accumulated 1-kestose from sucrose. The X-ray crystal structure of H395R/F473Y suggests that its catalytic pocket is unfavorable for binding of sucrose while favorable for transfructosylation.

PubMed: 37280168
DOI: 10.1093/bbb/zbad074

Experimental method

X-RAY DIFFRACTION (1.36 Å)