   1.14.13.38 | more |
a otcC disruption mutant strain of Streptomyces rimosus synthesizes a novel C-17 polyketide, the ability to make a 19-carbon backbone in the mutant strain is restored when the inactive mutant enzyme, with three essential glycine residues of the NADH-binding domain mutated by site-directed mutagenesis, is expressed in the disruption mutant strain, thus the quarternary structure of the enzyme is required, not only the its activity, in the synthase complex |
674496 |
| 1.14.13.38 | more |
recombinant overexpression of gene oxySin Saccharomyces cerevisiae, functional coexpression with heterologous dehydrotetracycline reductase CtcM, and the F420 reductase FNO. Biosynthesis of tetracycline is enabled by OxyS performing just one hydroxylation step in Saccharomyces cerevisiae despite its previous characterization as a double hydroxylase. This single hydroxylation enables the purification and structural characterization of a hypothetical intermediate in oxytetracycline biosynthesis that can explain structural differences between oxytetracycline and chlortetracycline. Using the alternative enzyme CtcM from the chlortetracycline pathway instead of OxyR yields in vitro an increased ratio of tetracycline to oxytetracycline. A unique cofactor to the last steps of the tetracyclines' biosynthesis that is not native to Saccharomyces cerevisiae is cofactor F420, a lactyl oligoglutamate phosphodiester derivative of 7,8-didemethyl-8-hydroxy-5-deazariboflavin (Fo). Fo is much more synthetically accessible than F420. Fo can replace F420 in tetracycline biosynthesis. Three F420 reductase candidates from Mycobacterium tuberculosis, Archaeoglobus fulgidus, and Streptomyces griseus are explored, and the enzyme from Archaeoglobus fulgidus is chosen. Method development and evaluation, method optimization, overview |
763803 |
