摘要
克隆并分析了拟南芥（Ａｒａｂｉｄｏｐｓｉｓｔｈａｌｉａｎａ（Ｌ．）Ｈｅｙｎｈ．）ＡｔＪ３的ｃＤＮＡ核苷酸序列，并证明其翻译产物与Ｅ．ｃｏｌｉ的ＤｎａＪ蛋白高度同源。ＡｔＪ３蛋白分子中具有全部这类蛋白的典型特征包括Ｊ结构域（ｄｏｍａｉｎ）、Ｇ或ＧＦ结构域、富含半胱氨酸的锌指结构域，Ｃ末端的ＣＡＱＱ是一个蛋白法尼基化信号。用ＡｔＪ３的ｃＤＮＡ序列末端非翻译区作探针，从拟南芥基因组文库中分离获得ＡｔＪ３基因。基因序列分析表明该基因是由被５个内含子分隔的６个外显子组成。根据Ｓｏｕｔｈｅｒｎ杂交分析，ＡｔＪ３基因为单拷贝基因。Ｎｏｒｔｈｅｒｎ分析结果表明，ＡｔＪ３在子叶、叶、根、花及长角果中都表达。
The nucleotide sequence of a cDNA clone from Arabidopsis thaliana (L.) Heynh. “ecotype Columbia” was determined. The open reading frame encoded a protein, AtJ3, which was highly homologous to DnaJ protein of E. coli. The predicted amino acid sequence of AtJ3 contained J domain, G or GFdomain, Cysteine rich Zn finger like sequence, which were all characteristic of this class of DnaJ homologues. And the C teminal of AtJ3 was CAQQ, a farnesylation motif. Using primers based on the cDNA, the corresponding gene AtJ3 was isolated and sequenced. The structure of this gene consisted of six exons interrupted by five introns. The results of Southern analysis indicated that AtJ3 was a single structure gene. AtJ3 was constitutively expressed in cotyledons, leaves, roots, flowers, and siliques based on Northern analysis. Heat shock at 35 ℃ led to increase in mRNA expression in leaves.
