Increase in D-tagatose Production Rate by Site-directed Mutagenesis of L-arabinose Isomerase from Geobacillus thermodenitrificans

• Published in: Biotechnology letters Vol. 28; no. 3; pp. 145 - 149
• Main Authors: Oh, Hyo-Jung, Kim, Hye-Jung, Oh, Deok-Kun
• Format: Journal Article
• Language: English
• Published: Dordrecht Kluwer Academic Publishers 01.02.2006; Springer; Springer Nature B.V
• Subjects: Aldose-Ketose Isomerases - genetics; Aldose-Ketose Isomerases - metabolism; Amino acids; aromatic compounds; Bacillaceae - genetics; Bacillaceae - metabolism; Bacillus thermodenitrificans; Biological and medical sciences; Biotechnology; Fundamental and applied biological sciences. Psychology; galactose; Geobacillus thermodenitrificans; Hexoses - biosynthesis; Mutagenesis; Mutagenesis, Site-Directed; mutants; Mutation; Recombinant Proteins - genetics; Recombinant Proteins - metabolism; site-directed mutagenesis; tagatose; kinetic parameters; site-directed mutagenesis; Isomerases; Intramolecular oxidoreductases; D-tagatose production; Enzyme; Site directed mutagenesis; Production; Kinetic parameter; L-Arabinose isomerase; Geobacillus thermodenitrificans
• ISSN: 0141-5492; 1573-6776
• DOI: 10.1007/s10529-005-5327-4

Among single-site mutations of L-arabinose isomerase derived from Geobacillus thermodenitrificans, two mutants were produced having the lowest and highest activities of D-tagatose production. Site-directed mutagenesis at these sites showed that the aromatic ring at amino acid 164 and the size of amino acid 475 were important for D-tagatose production. Among double-site mutations, one mutant converted D-galactose into D-tagatose with a yield of 58% whereas the wild type gave 46% D-tagatose conversion after 300 min at 65 °C.