4″-Oxo-avermectin is a key intermediate in the manufacture of the insecticide emamectin benzoate from the natural product avermectin. Seventeen Streptomyces strains with the ability to oxidize avermectin to 4″-oxo-avermectin in a regioselective manner have been discovered, and the enzymes responsible for this reaction were found to be CYPs (cytochrome P450 mono-oxygenases). The genes for these enzymes have been cloned, sequenced and compared to reveal a new subfamily of CYPs. The biocatalytic enzymes have been overexpressed in Escherichia coli, Streptomyces lividans and solvent-tolerant Pseudomonas putida strains using different promoters and vectors. FDs (ferredoxins) and FREs (ferredoxin:NADP+ reductases) were also cloned from Streptomyces coelicolor and biocatalytic Streptomyces strains, and tested in co-expression systems to optimize the electron transport. Subsequent studies showed that increasing the biocatalytic conversion levels to commercial relevance results in the production of several side products in significant amounts. Chimaeric Ema CYPs were created by sequential rounds of GeneReassembly™, a proprietary directed evolution method, and selected for improved substrate specificity by high-throughput screening.
Skip Nav Destination
Article navigation
December 2006
-
Cover Image
Cover Image
- PDF Icon PDF LinkFront Matter
- PDF Icon PDF LinkTable of Contents
Conference Article|
October 25 2006
Biocatalytic conversion of avermectin into 4″-oxo-avermectin: discovery, characterization, heterologous expression and specificity improvement of the cytochrome P450 enzyme
I. Molnár;
I. Molnár
1
*Syngenta Biotechnology, Inc., Research Triangle Park, NC 27709, U.S.A.
1To whom correspondence should be addressed, at the present address: Natural Products Center, Office of Arid Land Studies, College of Agriculture and Life Sciences, University of Arizona, Tucson, AZ 85706, U.S.A. (email imolnar@cals.arizona.edu).
Search for other works by this author on:
V. Jungmann;
V. Jungmann
†Syngenta AG, CH-4002 Basel, Switzerland
Search for other works by this author on:
J. Stege;
J. Stege
‡Diversa Corporation, 4955 Directors Place, San Diego, CA 92121, U.S.A.
Search for other works by this author on:
A. Trefzer;
A. Trefzer
2
‡Diversa Corporation, 4955 Directors Place, San Diego, CA 92121, U.S.A.
Search for other works by this author on:
J.P. Pachlatko
J.P. Pachlatko
†Syngenta AG, CH-4002 Basel, Switzerland
Search for other works by this author on:
Publisher: Portland Press Ltd
Received:
June 20 2006
Online ISSN: 1470-8752
Print ISSN: 0300-5127
© 2006 The Biochemical Society
2006
Biochem Soc Trans (2006) 34 (6): 1236–1240.
Article history
Received:
June 20 2006
Citation
I. Molnár, V. Jungmann, J. Stege, A. Trefzer, J.P. Pachlatko; Biocatalytic conversion of avermectin into 4″-oxo-avermectin: discovery, characterization, heterologous expression and specificity improvement of the cytochrome P450 enzyme. Biochem Soc Trans 1 December 2006; 34 (6): 1236–1240. doi: https://doi.org/10.1042/BST0341236
Download citation file:
Sign in
Don't already have an account? Register
Sign in to your personal account
You could not be signed in. Please check your email address / username and password and try again.
Captcha Validation Error. Please try again.