A novel plastid-targeted J-domain protein in Arabidopsis thaliana
A novel plastid-targeted J-domain protein in Arabidopsis thaliana
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DOI：
10.1023/a:1010665702621
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发表时间：
2001-01-01
影响因子：
5.1
通讯作者：
Gray, JC
中科院分区：
文献类型：
--
作者：
Orme, W;Walker, AR;Gray, JC
拟南芥cDNA编码ATJ11，已知的最小的J-结构域蛋白，已被分离和表征。161个氨基酸残基的前体蛋白在体外合成和进口的分离豌豆叶绿体，它被定位到基质和切割成一个成熟的蛋白质的125个氨基酸残基。成熟蛋白由一个80个氨基酸的J-结构域，和N-和C-末端延伸的24和21个氨基酸残基，分别，这表明在其他DnaJ相关蛋白的区域没有相似性。大肠杆菌产生的ATJ11对E. coli DnaK对荧光素酶的复性有抑制作用，但DnaK不能促进荧光素酶的复性，DnaJ、GrpE对荧光素酶的复性有抑制作用。ATJ11由4号染色体上的单拷贝基因编码，并在所有检测的植物器官中表达。ATJ11的一个片段，显示72%的同一性，在2号染色体上的4号染色体的4.5 Mb重复中编码。这些蛋白代表了一类新的J结构域蛋白。
Arabidopsis cDNAs encoding ATJ11, the smallest known J-domain protein, have been isolated and characterized. The precursor protein of 161 amino acid residues was synthesized in vitro and imported by isolated pea chloroplasts where it was localized to the stroma and cleaved to a mature protein of 125 amino acid residues. The mature protein consists of an 80 amino acid J-domain, and N- and C-terminal extensions of 24 and 21 amino acid residues, respectively, which show no similarity to regions in other DnaJ-related proteins. ATJ11 produced in Escherichia coli stimulated the weak ATPase activity of E. coli DnaK, but was unable to stimulate refolding of firefly luciferase by DnaK, and inhibited refolding by DnaK, DnaJ and GrpE. ATJ11 is encoded by a single-copy gene on chromosome 4, and is expressed in all plant organs examined. A paralogue of ATJ11, showing 72% identity, is encoded in a 4.5 Mb duplication of chromosome 4 on chromosome 2. These proteins represent a novel class of J-domain proteins.