Versatility of Enzymes Catalyzing Late Steps in Polyene 67-121C Biosynthesis

Polyene macrolide biosynthesis in streptomycetes and related bacteria: recent advances from genome sequencing and experimental studies

“…In contrast, two GTs that normally act on aromatic heptaenes do not recognise amphotericin aglycones in vivo. These are the PerDI perosaminyltransferase from S. cacaoi and the AceDI mycosaminyltransferase from A. caeruleus (Hutchinson et al, 2010;Stephens et al, 2013). These enzymes appear to have a lower tolerance for unnatural acceptors.…”

Engineered biosynthesis and characterisation of disaccharide-modified 8-deoxyamphoteronolides

“…3). This was predicted from the high sequence homology between 6 NypY and known inverting polyene glycosyltransferases (PegA, AmphDI and NysDI) that use GDP--Dmannose or GDP--D-mycosamine Stephens et al, 2013;De Poire et al, 2013).…”

Engineered Biosynthesis of Disaccharide-Modified Polyene Macrolides

“…The candicidin producer S. albidoflavus DSM40624 was transformed with the pIAGO-pegA1 (20) and pIAGO-nypY plasmids. The transformants were cultured, and polyenes were extracted into methanol by the same procedures used for amphotericins.…”

“…Recently, we carried out draft genome sequencing of this organism and identified 67-121 late biosynthetic genes. The pegA gene for the extending glycosyltransferase was expressed in Streptomyces nodosus, but only trace amounts of mannosyl-amphotericins were produced (20). It was not possible to determine whether this was due to inefficient recognition of amphotericins by PegA, low intracellular levels of GDP-D-mannose, rapid export of amphotericins before mannosylation could occur, or other unknown limiting factors.…”

“…PegA and NypY show 51% sequence identity (20), suggesting that both enzymes use GDP-␣-D-mannose as the activated sugar donor. In this study, we investigated whether NypY could recognize amphotericin B or its analogs in vivo.…”