Arabidopsis AtIscA-I is affected by deficiency of Fe-S cluster biosynthetic scaffold AtCnfU-V.
Arabidopsis AtIscA-I is affected by deficiency of Fe-S cluster biosynthetic scaffold AtCnfU-V.
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DOI：
10.1016/j.bbrc.2005.12.104
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发表时间：
2006-02
影响因子：
3.1
通讯作者：
T. Yabe;M. Nakai
中科院分区：
文献类型：
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作者：
T. Yabe;M. Nakai
IscA被认为是铁硫簇生物合成机制的支架蛋白。我们已经确定了IscA同源物定位到质体，称为AtIscA-I，在拟南芥。AtIscA-I蛋白在拟南芥中分析的所有组织中明显组成型表达。AtIscA-I蛋白作为可溶性蛋白存在于基质中，其倾向于形成同源二聚体并且可以宿主[2Fe-2S]样簇。质体中蛋白质的完全丧失在正常植物生长或主要铁硫蛋白的生物发生中均未引起任何显著缺陷，表明这种蛋白质对于这些功能不是必需的或多余的。相反，三种质体定位的CnfU支架蛋白之一AtCnfU-V的丢失导致AtIscA-I水平的显著降低。这些数据表明，AtIscA-I支架的有效生物合成需要另一种必需的支架蛋白CnfU的功能。
IscA has been proposed to be a scaffold protein of the iron–sulfur cluster biosynthetic machinery. We have identified the IscA homolog to be localized to plastids, termed AtIscA-I, in Arabidopsis thaliana. The AtIscA-I protein was apparently constitutively expressed in all tissues analyzed in Arabidopsis. The AtIscA-I protein exists in the stroma as a soluble protein which tends to form a homo-dimer and can host a [2Fe–2S]-like cluster. Complete loss of the protein from plastids did not cause any significant defect either in normal plant growth or in biogenesis of major iron–sulfur proteins, indicating this protein is not essential or redundant for these functions. In contrast, loss of one of the three plastid-localized CnfU scaffold proteins, AtCnfU-V, caused significant reduction in the level of AtIscA-I. These data suggest that efficient biogenesis of AtIscA-I scaffold requires function of another essential scaffold protein CnfU.