Role of the LolP cytochrome P450 monooxygenase in loline alkaloid biosynthesis.
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.
Spiering
Martin J
MJ
Department of Plant Pathology, University of Kentucky, 1405 Veterans Drive, Lexington, KY 40546-0312, USA.
Faulkner
Jerome R
JR
Zhang
Dong-Xiu
DX
Machado
Caroline
C
Grossman
Robert B
RB
Schardl
Christopher L
CL
D000470:Alkaloids / Q000096:biosynthesis* / Q000737:chemistry; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics / Q000378:metabolism*; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D006999:Hypocreales / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics* / Q000378:metabolism; D011523:Protoplasts / Q000378:metabolism
D000470:Alkaloids; D005656:Fungal Proteins; D003577:Cytochrome P-450 Enzyme System; C059478:loline