Modulating the Properties of Metal-Sensing Whole-Cell Bioreporters by Interfering with Escherichia coli Metal Homeostasis.
J Microbiol Biotechnol
; 28(2): 323-329, 2018 Feb 28.
Article
em En
| MEDLINE
| ID: mdl-29212299
ABSTRACT
In Escherichia coli, the transcription of genes related to metal homeostasis is activated by the presence of target metals. The promoter regions of those genes can be fused with reporter genes to generate whole-cell bioreporters (WCBs); these organisms sense the presence of target metals through reporter gene expression. However, the limited number of available promoters for sensing domains restricts the number of WCB targets. In this study, we have demonstrated an alternative method to generate novel WCBs, based on the notion that since the sensing mechanisms of WCBs are related to metal transportation systems, their properties can be modulated by disrupting metal homeostasis. Mutant E. coli strains were generated by deleting the znt-operon genes zntA, which encodes a zinc-export protein, and zntR, which encodes a znt-operon regulatory protein, to investigate the effects on the metal-sensing properties of WCBs. Deletion of zntA increased the sensitivity but abolished the selectivity of cadmium-sensing WCBs, whereas arsenic-sensing WCBs gained sensitivity toward cadmium. When zntR was deleted, cadmium-sensing WCBs lost the ability to detect cadmium, and this was recovered by introducing exogenous zntR. In addition, the metal-binding site of ZntR was genetically engineered to modulate metal selectivity. This study provides a valuable platform for the development of novel E. coli-based WCBs.
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Base de dados:
MEDLINE
Assunto principal:
Técnicas Biossensoriais
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Regulação Bacteriana da Expressão Gênica
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Genes Reporter
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Escherichia coli
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Homeostase
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Metais
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
J Microbiol Biotechnol
Ano de publicação:
2018
Tipo de documento:
Article