HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

J. Biol. Chem., Vol. 283, Issue 10, 6067-6075, March 7, 2008

This Article Full Text Full Text (PDF) All Versions of this Article: 283/10/6067    most recent M708950200v1 Submit a Letter to Editor Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Rontein, D. Articles by Tissier, A. Search for Related Content PubMed PubMed Citation Articles by Rontein, D. Articles by Tissier, A. Social Bookmarking                      What's this?

CYP725A4 from Yew Catalyzes Complex Structural Rearrangement of Taxa-4(5),11(12)-diene into the Cyclic Ether 5(12)-Oxa-3(11)-cyclotaxane^*

Denis Rontein¹, Sandrine Onillon, Gaëtan Herbette, Agnes Lesot^¶, Danièle Werck-Reichhart^¶, Christophe Sallaud, and Alain Tissier

From the Librophyt, Centre de Cadarache, 13115 St. Paul-Lez-Durance, France, Spectropole, Campus Scientifique de Saint Jérôme, Aix-Marseille Université, 13397 Marseille cedex 20, France, and the ^¶Department Plant Stress Response, Institute of Plant Molecular Biology, CNRS-UPR2357, Université Louis Pasteur, 20 Rue Goethe, 67000 Strasbourg, France

Taxa-4(5),11(12)-diene is the first committed precursor of functionalized taxanes such as paclitaxel, a successful anticancer drug. Biosynthesis of taxanes in yew involves several oxidations, a number of which have been shown to be catalyzed by cytochrome P-450 oxygenases. Hydroxylation of the C-5 of taxa-4(5),11(12)-diene is believed to be the first of these oxidations, and a gene encoding a taxa-4(5),11(12)-diene 5-hydroxylase (CYP725A4) was recently described (Jennewein, S., Long, R. M., Williams, R. M., and Croteau, R. (2004) Chem. Biol. 11, 379–387). In an attempt to produce the early components of the paclitaxel pathway by a metabolic engineering approach, cDNAs encoding taxa-4(5),11(12)-diene synthase and CYP725A4 were introduced in Nicotiana sylvestris for specific expression in trichome cells. Their co-expression did not lead to the production of the expected 5-hydroxytaxa-4(20),11(12)-diene. Instead, taxa-4(5),11(12)-diene was quantitatively converted to a novel taxane that was purified and characterized. Its structure was determined by NMR analysis and found to be that of 5(12)-oxa-3(11)-cyclotaxane (OCT) in which the eight-carbon B-ring from taxa-4(5),11(12)-diene is divided into two fused five-carbon rings. In addition, OCT contains an ether bridge linking C-5 and C-12 from opposite sides of the molecule. OCT was also the sole major product obtained after incubation of taxa-4(5),11(12)-diene with NADPH and microsomes prepared from recombinant yeast expressing CYP725A4. The rearrangement of the taxa-4(5),11(12)-diene ring system is thus mediated by CYP725A4 only and does not rely on additional enzymes or factors present in the plant. The complex structure of OCT led us to propose a reaction mechanism involving a sequence of events so far unknown in P-450 catalysis.

Received for publication, October 31, 2007 , and in revised form, December 20, 2007.

^* The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

¹ To whom correspondence should be addressed: Librophyt, Centre de Cadarache, Bâtiment 185, 13115 St. Paul-lez-Durance, France. Tel.: 33-442-574-941; Fax: 33-442-574-439; E-mail: denis.rontein{at}librophyt.com.

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				C. Sallaud, D. Rontein, S. Onillon, F. Jabes, P. Duffe, C. Giacalone, S. Thoraval, C. Escoffier, G. Herbette, N. Leonhardt, et al. A Novel Pathway for Sesquiterpene Biosynthesis from Z,Z-Farnesyl Pyrophosphate in the Wild Tomato Solanum habrochaites PLANT CELL, January 1, 2009; 21(1): 301 - 317. [Abstract] [Full Text] [PDF]