A new class of proteins capable of binding transition metals
A new class of proteins capable of binding transition metals
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DOI：
10.1023/a:1006367609556
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发表时间：
1999-09-01
影响因子：
5.1
通讯作者：
Randall, SK
中科院分区：
文献类型：
--
作者：
Dykema, PE;Sipes, PR;Randall, SK
离子的吸收、转运和固存对满足植物生长发育的营养需求至关重要。此外，这些过程的调节对植物耐受有毒离子水平至关重要。通过对拟南芥和甘氨酸max cdna编码的异丙烯酰化蛋白的检测，发现了一个独特的含有假定金属结合基序的蛋白家族（核心序列为M/LXCXXC）。在这里，我们描述了这类新的蛋白质，它们能够被异戊二烯化并结合过渡金属离子。这个家族的成员含有共识异戊烯酰化（CaaX）位点，我们证明了它在体外是有效的异戊烯酰化。ATFP3是拟南芥家族的代表，在大肠杆菌中表达，并在体外检测了金属结合活性。对ATFP3与金属螯合柱（IMAC）相互作用的分析表明，它与Cu2+、Ni2+或Zn2+结合。为了测试具有这些特征的蛋白质是否存在于其他植物物种中，我们在体内用[C-14]甲羟戊酸标记烟草BY2细胞，并测试由此产生的甲羟戊酸标记的蛋白质的金属结合活性。发现了几种与铜- imac柱结合的可溶性异丙烯化蛋白。与这些蛋白在植物中的广泛分布一致，它们在拟南芥、大豆和烟草中都有发现。
Ion uptake, transport, and sequestration are essential to meet the nutritional requirements for plant growth and development. Furthermore, regulation of these processes is critical for plants to tolerate toxic levels of ions. The examination of isoprenylated proteins encoded by Arabidopsis thaliana and Glycine max cDNAs revealed a unique family of proteins containing putative metal-binding motifs (the core sequence is M/LXCXXC). Here, we describe this new class of proteins, which are capable of being isoprenylated and binding transition metal ions. Members of this family contain consensus isoprenylation (CaaX) sites, which we demonstrate are efficiently isoprenylated in vitro. ATFP3, a representative of the Arabidopsis family, was expressed in Escherichia coli and examined for metal-binding activity in vitro. Analysis of the interaction of ATFP3 with metal-chelating columns (IMAC) suggested that it binds to Cu2+, Ni2+, or Zn2+. To test whether proteins with these characteristics are present in other plant species, tobacco BY2 cells were labeled in vivo with [C-14]mevalonate and the resulting mevalonate-labeled proteins were tested for metal-binding activity. Several soluble, isoprenylated proteins which bound copper-IMAC columns were revealed. Consistent with a wide-spread distribution of these proteins in plants, their presence was observed in Arabidopsis, soybean, and tobacco.