从商陆抑制性消减杂交文库中获得金属硫蛋白PaMT,基因全长141 bp,编码46个氨基酸,等电点和分子量分别为3.85和4.7 kD,具有12个半胱氨酸残基:具有典型的金属硫蛋白结构(CXC结构). 进化树和蛋白结构分析表明它属于金属硫蛋白家族. PaMT主要在根中表达,且受重金属胁迫上调其基因表达. 蛋白融合表达表明,PaMT可以提高大肠杆菌对重金属离子的耐受力.
A full-length cDNA of metallothionein, designated PaMT, was cloned from SSH libraries. PaMT consists of 141 bp that code 46 amino acids. Classic structure (cxc) of metallothionein and the phylogenetic tree analysis show that PaMT belongs to metallothionein family. PaMT is preferentially expressed in root and its expression is strongly up-regulated by heavy metal stress. PaMT-NusA fusion protein expressed in Coli BL21 plays a role in the tolerance to heavy metal toxicity.
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