Genetic and biochemical evidence for the involvement of α-1,4 glucanotransferases in amylopectin synthesis
Genetic and biochemical evidence for the involvement of α-1,4 glucanotransferases in amylopectin synthesis
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DOI：
10.1104/pp.120.4.993
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发表时间：
1999-08-01
期刊：
影响因子：
7.4
通讯作者：
Ball, S
中科院分区：
文献类型：
--
作者：
Colleoni, C;Dauvillée, D;Ball, S
我们描述了莱茵衣藻（Chlamydomonas reinhardtii） STA11基因的一个新突变，该突变导致颗粒淀粉沉积显著减少，支链淀粉结构和颗粒形状发生重大改变。这种缺陷同时导致线性麦芽寡糖的积累。sta11-1突变导致α -1,4葡聚糖转移酶，即歧化酶（d酶）的缺失。在基因剂量实验中，发现d酶活性与野生型等位基因剂量的数量有关。所有其他参与淀粉生物合成的酶，包括adp -葡萄糖焦磷酸化酶、去分支酶、可溶性和颗粒结合淀粉合成酶、分支酶、磷酸化酶、铜-葡萄糖苷酶（麦芽糖酶）和淀粉酶，都不受突变的影响。这些数据表明，d酶是单细胞藻莱因哈德梭菌正常淀粉颗粒生物生成所必需的。
We describe a novel mutation in the Chlamydomonas reinhardtii STA11 gene, which results in significantly reduced granular starch deposition and major modifications in amylopectin structure and granule shape. This defect simultaneously leads to the accumulation of linear malto-oligosaccharides. The sta11-1 mutation causes the absence of an alpha-1,4 glucanotransferase known as disproportionating enzyme (D-enzyme). D-enzyme activity was found to be correlated with the amount of wild-type allele doses in gene dosage experiments. All other enzymes involved in starch biosynthesis, including ADP-glucose pyrophosphorylase, debranching enzymes, soluble and granule-bound starch synthases, branching enzymes, phosphorylases, cu-glucosidases (maltases), and amylases, were unaffected by the mutation. These data indicate that the D-enzyme is required for normal starch granule biogenesis in the monocellular alga C. reinhardtii.