We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Biochemical characterization of TASSELSEED 2, an essential plant short-chain dehydrogenase/reductase with broad spectrum activities.
- Authors
Xiaoqiu Wu; Knapp, Stefan; Stamp, Anna; Stammers, David K.; Jörnvall, Hans; Dellaporta, Stephen L.; Oppermann, Udo
- Abstract
The development of unisexual flowers in maize and other plants proceeds through selective elimination of floral organs in an initially bisexual floral meristem. The essential character of the tasselseed 2 gene ( TS2) in this cell-death pathway has been established previously. Molecular cloning of TS2 reveals membership to the evolutionarily conserved superfamily of short-chain dehydrogenases/reductases, but its substrate specificity remained unknown. Recombinant TS2 protein was produced in Escherichia coli, and purified to apparent homogeneity. Analytical ultracentrifugation and gel filtration experiments show that TS2 is a tetrameric enzyme. Thermal denaturation followed by circular dichroism spectroscopy reveals that TS2 binds NAD(H) and NAD(P)(H). Substrate screening demonstrates that TS2 converts steroids with specificities found at positions 3 and 17, and several dicarbonyl and quinone compounds, thus establishing TS2 as a plant 3β/17β-hydroxysteroid dehydrogenase and carbonyl/quinone reductase. Taken together, the genetic data and the substrate specificities determined suggest that TS2 converts specific plant compounds and acts as a prereceptor control mechanism, in a manner similar to that of mammalian hydroxysteroid dehydrogenases.
- Subjects
MERISTEMS; MOLECULAR cloning; PLANT cells &; tissues; DEHYDROGENASES; ESCHERICHIA coli
- Publication
FEBS Journal, 2007, Vol 274, Issue 5, p1172
- ISSN
1742-464X
- Publication type
Article
- DOI
10.1111/j.1742-4658.2007.05642.x