UDP-glucuronic acid:anthocyanin glucuronosyltransferase from red daisy (Bellis perennis) flowers -: Enzymology and phylogenetics of a novel glucuronosyltransferase involved in flower pigment biosynthesis
UDP-glucuronic acid:anthocyanin glucuronosyltransferase from red daisy (Bellis perennis) flowers -: Enzymology and phylogenetics of a novel glucuronosyltransferase involved in flower pigment biosynthesis
复制标题
DOI：
10.1074/jbc.m410537200
复制
发表时间：
2005-01-14
影响因子：
4.8
通讯作者：
Nakayama, T
中科院分区：
文献类型：
--
作者：
Sawada, S;Suzuki, H;Nakayama, T
与关于脊椎动物葡萄糖醛酸基转移酶(GUATS)的丰富的生化和遗传信息相比，关于植物GUATS的作用和系统发育的信息有限。本文报道了一种与红雏菊(Bellis Perennis)花色素生物合成有关的新的UGAT基因的纯化、鉴定和基因克隆。纯化的BpUGAT是一种可溶性单体酶，其相对分子质量为54 kDa，在pH 7.0，30℃时，催化3-O-6“-O-丙二酸基葡萄糖苷3-O-O”-O-丙二酸基葡萄糖苷的2“-羟基发生区域特异性转移，k(CAT)为34 S(-1)。BpUGAT对氰基3-O-葡萄糖苷(如K-m为氰基3-O-6“-O-丙二酰基葡萄糖苷，19微米)和UDP-葡萄糖醛酸脂(K-m，476微米)具有高度专一性。根据纯化的酶的氨基酸序列，获得了BpUGAT的全长cDNA。定量PCR分析表明，BpUGAT转录本可以在红花瓣中特异地检测到，这与植物中酶活性的时空分布一致，也与该酶在色素生物合成中的作用一致。序列分析表明，BpUGAT与糖基转移酶超家族中的糖基转移酶1(GT1)家族相关(根据碳水化合物活性酶(CAZy)数据库)。在包含脊椎动物GATS和植物次生产物糖基转移酶的GT1家族成员中，与植物的类黄酮鼠李糖基转移酶的序列相似性最高(28-40%)。尽管BpUGAT的生物学作用(色素生物合成)和酶性质与脊椎动物GUAT显著不同，但这两种GUAT有一个相似之处，即这些酶产生的产物更易溶于水，从而促进它们在空泡中积累(在BpUGAT中)或它们从脊椎动物细胞中排泄)，证实了GT1家族成员在亲脂小分子代谢中的普遍意义。
In contrast to the wealth of biochemical and genetic information on vertebrate glucuronosyltransferases (UGATs), only limited information is available on the role and phylogenetics of plant UGATs. Here we report on the purification, characterization, and cDNA cloning of a novel UGAT involved in the biosynthesis of flower pigments in the red daisy (Bellis perennis). The purified enzyme, BpUGAT, was a soluble monomeric enzyme with a molecular mass of 54 kDa and catalyzed the regiospecific transfer of a glucuronosyl unit from UDPglucuronate to the 2"-hydroxyl group of the 3-glucosyl moiety of cyanidin 3-O-6"-O-malonylglucoside with a k(cat) value of 34 s(-1) at pH 7.0 and 30 degreesC. BpUGAT was highly specific for cyanidin 3-O-glucosides (e.g. K-m for cyanidin 3-O-6"-O-malonylglucoside, 19 muM) and UDP-glucuronate (K-m, 476 muM). The BpUGAT cDNA was isolated on the basis of the amino acid sequence of the purified enzyme. Quantitative PCR analysis showed that transcripts of BpUGAT could be specifically detected in red petals, consistent with the temporal and spatial distributions of enzyme activity in the plant and also consistent with the role of the enzyme in pigment biosynthesis. A sequence analysis revealed that BpUGAT is related to the glycosyltransferase 1 (GT1) family of the glycosyltransferase superfamily ( according to the Carbohydrate-Active Enzymes (CAZy) data base). Among GT1 family members that encompass vertebrate UGATs and plant secondary product glycosyltransferases, the highest sequence similarity was found with flavonoid rhamnosyltransferases of plants (28 - 40% identity). Although the biological role ( pigment biosynthesis) and enzymatic properties of BpUGAT are significantly different from those of vertebrate UGATs, both of these UGATs share a similarity in that the products produced by these enzymes are more water-soluble, thus facilitating their accumulation in vacuoles (in BpUGAT) or their excretion from cells in vertebrate UGATs), corroborating the proposed general significance of GT1 family members in the metabolism of small lipophilic molecules.