5o16

Publication Abstract from PubMed

Oxygen-containing heterocycles are a common structural motif of polyketide natural products and contribute significantly to their biological activity. However, there are only limited reports of the responsible cyclases. Here, we report structural and mechanistic investigations on AmbDH3, a polyketide synthase domain with dual activity as dehydratase (DH) and pyran-forming cyclase in ambruticin biosynthesis. AmbDH3 is similar to monofunctional DH domains, using H51 and D215 for dehydration. V173 was confirmed as a diagnostic residue for cyclisation activity by a mutational study and enzymatic in vitro experiments. Similar motifs were observed in the seemingly monofunctional AmbDH2, which also shows an unexpected cyclase activity. Our results pave the way for mining of hidden cyclases in biosynthetic pathways. They also open interesting prospects for the generation of novel biocatalysts for chemoenzymatic synthesis and pyran-polyketides by combinatorial biosynthesis.

Insights into the dual Activity of a Bifunctional Dehydratase-Cyclase Domain.,Sung KH, Berkhan G, Hollmann T, Wagner L, Blankenfeldt W, Hahn F Angew Chem Int Ed Engl. 2017 Oct 30. doi: 10.1002/anie.201707774. PMID:29084363^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.