Author | dc.contributor.author | Troncoso, Claudia | |
Author | dc.contributor.author | Cárcamo, José J. | es_CL |
Author | dc.contributor.author | Hedden, Peter | es_CL |
Author | dc.contributor.author | Tudzynski, Bettina | es_CL |
Author | dc.contributor.author | Rojas, M. Cecilia | es_CL |
Admission date | dc.date.accessioned | 2010-01-22T13:52:07Z | |
Available date | dc.date.available | 2010-01-22T13:52:07Z | |
Publication date | dc.date.issued | 2008-02 | |
Cita de ítem | dc.identifier.citation | PHYTOCHEMISTRY, Volume: 69,Issue: 3, Pages: 672-683, 2008 | en_US |
Identifier | dc.identifier.issn | 0031-9422 | |
Identifier | dc.identifier.uri | https://repositorio.uchile.cl/handle/2250/118972 | |
Abstract | dc.description.abstract | The multifunctional cytochrome P450 monooxygenases P450-1 and P450-2 from Fusarium fujikuroi catalyze the formation of GA14
and GA4, respectively, in the gibberellin (GA)-biosynthetic pathway. However, the activity of these enzymes is qualitatively and quantitatively
different in mutants lacking the NADPH:cytochrome P450 oxidoreductase (CPR) compared to CPR-containing strains. 3b-
Hydroxylation, a major P450-1 activity in wild-type strains, was strongly decreased in the mutants relative to oxidation at C-6 and
C-7, while synthesis of C19-GAs as a result of oxidative cleavage of C-20 by P450-2 was almost absent whereas the C-20 alcohol, aldehyde
and carboxylic acid derivatives accumulated. Interaction of the monooxygenases with alternative electron transport proteins could
account for these different product distributions. In the absence of CPR, P450-1 activities were NADH-dependent, and stimulated by
cytochrome b5 or by added FAD. These properties as well as the decreased efficiency of P450-1 and P450-2 in the mutants are consistent
with the participation of cytochrome b5:NADH cytochrome b5 reductase as redox partner of the gibberellin monooxygenases in the
absence of CPR. We provide evidence, from either incubations of GA12 (C-20 methyl) with cultures of the mutant suspended in
[18O]H2O or maintained under an atmosphere of [18O]O2:N2 (20:80), that GA15 (C-20 alcohol) and GA24 (C-20 aldehyde) are formed
directly from dioxygen and not from hydrolysis of covalently enzyme-bound intermediates. Thus these partially oxidized GAs correspond
to intermediates of the sequential oxidation of C-20 catalyzed by P450-2. | en_US |
Patrocinador | dc.description.sponsorship | This work was supported by Fondo Nacional de Ciencia y Tecnologı´a (Grant 1020140) and by the CONICYT/ DAAD Cooperation Program. | en_US |
Lenguage | dc.language.iso | en | en_US |
Publisher | dc.publisher | PERGAMON-ELSEVIER SCIENCE LTD | en_US |
Keywords | dc.subject | Fusarium fujikuroi | en_US |
Título | dc.title | Influence of electron transport proteins on the reactions catalyzed by Fusarium fujikuroi gibberellin monooxygenases | en_US |
Document type | dc.type | Artículo de revista | |