Diverse Combinatorial Biosynthesis Strategies for C-H Functionalization of Anthracyclinones.

spp. are "nature's antibiotic factories" that produce valuable bioactive metabolites, such as the cytotoxic anthracycline polyketides. While the anthracyclines have hundreds of natural and chemically synthesized analogues, much of the chemical diversity stems from enzymatic modifications to the saccharide chains and, to a lesser extent, from alterations to the core scaffold.

Evolution-inspired engineering of anthracycline methyltransferases.

soil bacteria produce hundreds of anthracycline anticancer agents with a relatively conserved set of genes. This diversity depends on the rapid evolution of biosynthetic enzymes to acquire novel functionalities. Previous work has identified -adenosyl-l-methionine-dependent methyltransferase-like proteins that catalyze 4-O-methylation, 10-decarboxylation, or 10-hydroxylation, with additional differences in substrate specificities.

Pathway Engineering of Anthracyclines: Blazing Trails in Natural Product Glycodiversification.

The anthracyclines are structurally diverse anticancer natural products that bind to DNA and poison the topoisomerase II-DNA complex in cancer cells. Rational modifications in the deoxysugar functionality are especially advantageous for synthesizing drugs with improved potency. Combinatorial biosynthesis of glycosyltransferases and deoxysugar synthesis enzymes is indispensable for the generation of glycodiversified anthracyclines.

The Rieske Oxygenase SnoT Catalyzes 2''-Hydroxylation of l-Rhodosamine in Nogalamycin Biosynthesis.

Nogalamycin is an anthracycline anti-cancer agent that intercalates into the DNA double helix. The binding is facilitated by two carbohydrate units, l-nogalose and l-nogalamine, that interact with the minor and major grooves of DNA, respectively. However, recent investigations have shown that nogalamycin biosynthesis proceeds through the attachment of l-rhodosamine (2''-deoxy-4''-epi-l-nogalamine) to the aglycone.

Evolution-guided engineering of non-heme iron enzymes involved in nogalamycin biosynthesis.

Microbes are competent chemists that are able to generate thousands of chemically complex natural products with potent biological activities. The key to the formation of this chemical diversity has been the rapid evolution of secondary metabolism. Many enzymes residing on these metabolic pathways have acquired atypical catalytic properties in comparison with their counterparts found in primary metabolism.

Enzymatic Synthesis of the C-Glycosidic Moiety of Nogalamycin R.

Carbohydrate moieties are essential for the biological activity of anthracycline anticancer agents such as nogalamycin, which contains l-nogalose and l-nogalamine units. The former of these is attached through a canonical O-glycosidic linkage, but the latter is connected via an unusual dual linkage composed of C-C and O-glycosidic bonds. In this work, we have utilized enzyme immobilization techniques and synthesized l-rhodosamine-thymidine diphosphate (TDP) from α-d-glucose-1-TDP using seven enzymes.