Structure-based Analysis of Apocarotenoid Biosynthesis

描述(申请人提供)：维甲酸是动物体内必需的信号分子，已成为常见的化学预防饮食制剂。类维甲酸的生物合成途径始于类胡萝卜素被类胡萝卜素裂解双加氧酶家族中的一个成员裂解，该家族首先在植物中发现。在植物中，CCDs参与植物激素脱落酸和一种控制植物结构的新型激素的生物合成。在动物体内，CCDs负责类维甲酸的生物合成，特别是视觉所必需的维生素A和对正常发育至关重要的维甲酸。目前，还不存在任何一种CCD的高分辨率结构信息。利用一个或多个CCDs的结构，可以对植物中的酶和代谢途径工程进行结构指导的方法，以控制植物的结构并提高营养品质。在动物身上，这种方法可能会导致对视觉生色团和信号分子维甲酸的产生有更好的理解。模式生物拟南芥中的CCDs家族为系统剖析复杂的CCDs的结构和功能特征提供了一系列相关基因。

DESCRIPTION (provided by applicant): Retinoids are essential signaling molecules in animals and have become common chemo-preventive dietary agents. The retinoid biosynthetic pathway begins with the cleavage of a carotenoid by a member of the Carotenoid Cleavage Dioxygenase (CCD) family of enzymes first discovered in plants. In plants, CCDs participate in the biosynthesis of the phytohormone abscisic acid and a novel hormone that controls plant architecture. In animals the CCDs are responsible for the biosynthesis of retinoids, notably vitamin A, which is necessary for vision, and retinoic acid, which is critical to normal development. Currently, no high resolution structural information for any CCD exists. With the structure of one or more CCDs, a structurally guided approach towards enzyme and metabolic pathway engineering in plants could be done to allow for the control of plant architecture as well as increase nutritional quality. In animals, this approach could lead to a greater understanding of the production of the visual chromophore and to the signaling molecule, retinoic acid. The CCD family in the model organism Arabidopsis thaliana provides a collection of related genes for the systematic dissection of the structural and functional features of the mechanistically complex CCDs.