کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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2181233 | 1095281 | 2008 | 8 صفحه PDF | دانلود رایگان |
The insecticidal loline alkaloids, produced by Neotyphodium uncinatum and related endophytes, are exo-1-aminopyrrolizidines with an ether bridge between C-2 and C-7. Loline alkaloids vary in methyl, acetyl, and formyl substituents on the 1-amine, which affect their biological activity. Enzymes for key loline biosynthesis steps are probably encoded by genes in the LOL cluster, which is duplicated in N. uncinatum, except for a large deletion in lolP2. The role of lolP1 was investigated by its replacement with a hygromycin B phosphotransferase gene. Compared to wild type N. uncinatum and an ectopic transformant, ΔlolP1 cultures had greatly elevated levels of N-methylloline (NML) and lacked N-formylloline (NFL). Complementation of ΔlolP1 with lolP1 under control of the Emericella nidulanstrpC promoter restored NFL production. These results and the inferred sequence of LolP1 indicate that it is a cytochrome P450, catalyzing oxygenation of an N-methyl group in NML to the N-formyl group in NFL.
Journal: Fungal Genetics and Biology - Volume 45, Issue 9, September 2008, Pages 1307–1314