Centro de Pesquisas em Biotecnologia, Universidade de São Paulo, Av. Prof. Lineu Prestes, 1730, Cidade Universitária, 05508-900 - São Paulo, SP, Brasil.
Environ Sci Technol. 2012 Aug 7;46(15):8325-32. doi: 10.1021/es3006207. Epub 2012 Jul 24.
This work describes the effects of the cell surface display of a synthetic phytochelatin in the highly metal tolerant bacterium Cupriavidus metallidurans CH34. The EC20sp synthetic phytochelatin gene was fused between the coding sequences of the signal peptide (SS) and of the autotransporter β-domain of the Neisseria gonorrhoeae IgA protease precursor (IgAβ), which successfully targeted the hybrid protein toward the C. metallidurans outer membrane. The expression of the SS-EC20sp-IgAβ gene fusion was driven by a modified version of the Bacillus subtilis mrgA promoter showing high level basal gene expression that is further enhanced by metal presence in C. metallidurans. The recombinant strain showed increased ability to immobilize Pb(2+), Zn(2+), Cu(2+), Cd(2+), Mn(2+), and Ni(2+) ions from the external medium when compared to the control strain. To ensure plasmid stability and biological containment, the MOB region of the plasmid was replaced by the E. coli hok/sok coding sequence.
这项工作描述了在高度耐受金属的细菌 Cupriavidus metallidurans CH34 中展示合成植物螯合肽的细胞表面对其产生的影响。EC20sp 合成植物螯合肽基因被融合到淋病奈瑟菌 IgA 蛋白酶前体（IgAβ）的信号肽（SS）和自转运β-结构域的编码序列之间，成功将杂合蛋白靶向 C. metallidurans 外膜。SS-EC20sp-IgAβ 基因融合的表达由枯草芽孢杆菌 mrgA 启动子的改良版本驱动，该启动子表现出高水平的基础基因表达，并且在 C. metallidurans 中存在金属时进一步增强。与对照菌株相比，重组菌株显示出从外部介质中固定更多 Pb(2+)、Zn(2+)、Cu(2+)、Cd(2+)、Mn(2+)和 Ni(2+)离子的能力增强。为了确保质粒稳定性和生物控制，质粒的 MOB 区域被大肠杆菌 hok/sok 编码序列取代。
