Structural Insights into Maize Viviparous14, a Key Enzyme in the Biosynthesis of the Phytohormone Abscisic Acid W
The key regulatory step in the biosynthesis of abscisic acid (ABA), a hormone central to the regulation of several important processes in plants, is the oxidative cleavage of the 11,12 double bond of a 9-cis-epoxycarotenoid. The enzyme viviparous14 (VP14) performs this cleavage in maize (Zea mays), making it a target for the rational design of novel chemical agents and genetic modifications that improve plant behavior through the modulation of ABA levels. The structure of VP14, determined to 3.2-{angstrom} resolution, provides both insight into the determinants of regio- and stereospecificity of this enzyme and suggests a possible mechanism for oxidative cleavage. Furthermore, mutagenesis of the distantly related CCD1 of maize shows how the VP14 structure represents a template for all plant carotenoid cleavage dioxygenases (CCDs). In addition, the structure suggests how VP14 associates with the membrane as a way of gaining access to its membrane soluble substrate.
- Research Organization:
- Brookhaven National Lab. (BNL), Upton, NY (United States). National Synchrotron Light Source
- Sponsoring Organization:
- DOE - OFFICE OF SCIENCE
- DOE Contract Number:
- DE-AC02-98CH10886
- OSTI ID:
- 1020156
- Report Number(s):
- BNL-96006-2011-JA; TRN: US201116%%136
- Journal Information:
- Plant Cell, Vol. 22, Issue 9; ISSN 1040-4651
- Country of Publication:
- United States
- Language:
- English
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GENETIC ANALYSIS OF ABSCISIC ACID BIOSYNTHESIS
Specific oxidative cleavage of carotenoids by VP14 of maize
Related Subjects
99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE
ABSCISIC ACID
BIOSYNTHESIS
CAROTENOIDS
CLEAVAGE
DESIGN
DOUBLE BONDS
ENZYMES
GENETICS
HORMONES
MAIZE
MEMBRANES
MODIFICATIONS
MODULATION
MUTAGENESIS
REGULATIONS
RESOLUTION
TARGETS
national synchrotron light source