Molecular and biochemical characterization of a cytokinin oxidase from maize
Molecular and biochemical characterization of a cytokinin oxidase from maize
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DOI：
10.1104/pp.125.1.378
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发表时间：
2001-01-01
期刊：
影响因子：
7.4
通讯作者：
Morris, RO
中科院分区：
文献类型：
--
作者：
Bilyeu, KD;Cole, JL;Morris, RO
人们普遍认为，细胞分裂素氧化酶在调节不同物种部分纯化的细胞分裂素氧化酶组分中的细胞分裂素水平方面起着主要作用，但尚未清楚地揭示该酶的性质或其生物学意义。现在详细介绍了最近分离的玉米(Zea Mays)细胞分裂素氧化酶基因(CKX1)及其部分拟南芥同源基因的基因组结构。在巴斯德毕赤酵母中表达无内含子CKX1，可以大量生产重组细胞分裂素氧化酶，便于进行详细的动力学和辅因子分析，并与天然酶进行比较。该酶是一种黄素蛋白，含有共价结合的黄素腺嘌呤二核苷酸，但没有检测到重金属。描述了该酶在玉米组织中的表达。
It is generally accepted that cytokinin oxidases, which oxidatively remove cytokinin side chains to produce adenine and the corresponding isopentenyl aldehyde, play a major role in regulating cytokinin levels in planta Partially purified fractions of cytokinin oxidase from various species have been studied for many years, but have yet to clearly reveal the properties of the enzyme or to define its biological significance. Details of the genomic organization of the recently isolated maize (Zea mays) cytokinin oxidase gene (ckx1) and some of its Arabidopsis homologs are now presented. Expression of an intronless ckx1 in Pichia pastoris allowed production of large amounts of recombinant cytokinin oxidase and facilitated detailed kinetic and cofactor analysis and comparison with the native enzyme. The enzyme is a flavoprotein containing covalently bound flavin adenine dinucleotide, but no detectable heavy metals. Expression of the oxidase in maize tissues is described.