| Literature DB >> 18655839 |
Martin J Spiering1, Jerome R Faulkner, Dong-Xiu Zhang, Caroline Machado, Robert B Grossman, Christopher L Schardl.
Abstract
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, DeltalolP1 cultures had greatly elevated levels of N-methylloline (NML) and lacked N-formylloline (NFL). Complementation of DeltalolP1 with lolP1 under control of the Emericella nidulans trpC 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.Entities:
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Year: 2008 PMID： 18655839 DOI： 10.1016/j.fgb.2008.07.001
Source DB: PubMed Journal: Fungal Genet Biol ISSN： 1087-1845 Impact factor: 3.495