Polyphosphate produced in recombinant Escherichia coli confers mercury resistance
Polyphosphate produced in recombinant Escherichia coli confers mercury resistance
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DOI：
10.1111/j.1574-6968.2002.tb11045.x
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发表时间：
2002-02-05
影响因子：
2.1
通讯作者：
Endo, G
中科院分区：
文献类型：
--
作者：
Pan-Hou, H;Kiyono, M;Endo, G
由假单胞菌K-62的mer a缺失的广谱meroperon与产气克雷伯菌的细菌多磷酸激酶基因（ppk）在pUC119载体中融合而成的大肠杆菌菌株。用pMKB18融合质粒在汞诱导的细菌中发现了大量的ppk特异性多磷酸盐，而在没有汞诱导的细胞中则没有。这些结果表明，PMKB18菌株对Hg2-和C6H5Hg-的抗性均高于其克隆载体pUC119的等基因菌株。重组菌株从Hg2-和C6H5Hg-污染的培养基中积累了更多的汞。转运到细胞质中的Hg2-似乎与重组细胞产生的多磷酸盐螯合结合。由于多磷酸盐不直接与C6H5Hg-螯合，转运的苯汞在螯合前被降解为Hg2-。这些结果表明，聚磷酸盐能够降低转运的Hg2-的细胞毒性，可能是通过聚磷酸盐与Hg2-之间的螯合作用。(C) 2002年欧洲微生物学会联合会。Elsevier Science b.v.出版。版权所有。
An Escherichia coli strain,as generated by fusion of a mer A-deleted broad-spectrum meroperon from Pseudomonas K-62 with a bacterial poly phosphate kinase gene (ppk) from Klebsiella aerogenes in vector pUC119. A large amount of the ppk-specified polyphosphate was identified in the mercury-induced bacterium with the fusion plasmid designated pMKB18 but not in the cells without mercury induction. These results suggest that the synthesis of polyphosphate as ell Lis the expression of the mer genes is mercury-inducible and regulated by merR The E. coli strain with PMKB18 was more resistant to both Hg2- and C6H5Hg- than its isogenic strain with cloning vector pUC119. The recombinant strain accumilated more mercury from Hg2-- and C6H5Hg- -contaminated medium. Hg2- transported into the cytoplasm appeared to be bound by chelation with the polyphosphate Produced by the recombinant cells. The transported phenylmercury was degraded to Hg2- before the chelation since polyphosphate did not directly chelate with C6H5Hg-. These results indicate that Polyphosphate is capable of reducing the cytotoxicity of the transported Hg2- probably via chelation between polyphosphate and Hg2-. (C) 2002 Federation of European Microbiological Societies. Published by Elsevier Science B.V.. All rights reserved.