Cloning of the Arabidopsis ent-kaurene oxidase gene GA3
Cloning of the Arabidopsis ent-kaurene oxidase gene GA3
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DOI：
10.1073/pnas.95.15.9019
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发表时间：
1998-07-21
影响因子：
11.1
通讯作者：
Dennis, ES
中科院分区：
文献类型：
--
作者：
Helliwell, CA;Sheldon, CC;Dennis, ES
拟南芥的GA3突变体是一个对赤霉素敏感的矮生植物。我们提供的数据表明，GA3-1突变体缺乏Ent-Kaurene氧化酶活性，这是赤霉素生物合成途径中细胞色素P450介导的第一步。通过使用传统的基于图谱的克隆和随机测序相结合的方法，我们确定了一个可能的细胞色素P450基因定位到与GA3相同的位置。相对于祖先系，两个GA3突变等位基因含有单一碱基变化，在预测的P450氨基酸序列中产生框内终止密码子。一个跨越P450基因座的基因组克隆补充了GA3-2突变体。推导出的GA3蛋白定义了另一类细胞色素P450酶。GA3基因在供试的所有组织中都有表达，其中花序组织的RNA丰度最高。
The ga3 mutant of Arabidopsis is a gibberellin-responsive dwarf. We present data showing that the ga3-1 mutant is deficient in ent-kaurene oxidase activity, the first cytochrome P450-mediated step in the gibberellin biosynthetic pathway. By using a combination of conventional map-based cloning and random sequencing we identified a putative cytochrome P450 gene mapping to the same location as GA3. Relative to the progenitor line, two ga3 mutant alleles contained single base changes generating in-frame stop codons in the predicted amino acid sequence of the P450. A genomic clone spanning the P450 locus complemented the ga3-2 mutant. The deduced GA3 protein defines an additional class of cytochrome P450 enzymes. The GA3 gene was expressed in all tissues examined, RNA abundance being highest in inflorescence tissue.