Increase in D-tagatose production rate by site-directed mutagenesis of L-arabinose isomerase from Geobacillus thermodenitrificans.
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 degrees C.
Oh
Hyo-Jung
HJ
Department of Bioscience and Biotechnology, Sejong University, Seoul, 143-747, South Korea.
Kim
Hye-Jung
HJ
Oh
Deok-Kun
DK
D019747:Aldose-Ketose Isomerases / Q000235:genetics / Q000378:metabolism*; D001406:Bacillaceae / Q000235:genetics / Q000378:metabolism*; D006601:Hexoses / Q000096:biosynthesis*; D016297:Mutagenesis, Site-Directed; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism
D006601:Hexoses; D011994:Recombinant Proteins; D019747:Aldose-Ketose Isomerases; C019715:L-arabinose isomerase; C030192:tagatose