Copy number of ArsR reporter plasmid determines its arsenite response and metal specificity.
Appl Microbiol Biotechnol
; 102(13): 5753-5761, 2018 Jul.
Article
em En
| MEDLINE
| ID: mdl-29766244
ABSTRACT
The key component in bacteria-based biosensors is a transcriptional reporter employed to monitor induction or repression of a reporter gene corresponding to environmental change. In this study, we made a series of reporters in order to achieve highly sensitive detection of arsenite. From these reporters, two biosensors were developed by transformation of Escherichia coli DH5α with pLHPars9 and pLLPars9, consisting of either a high or low copy number plasmid, along with common elements of ArsR-luciferase fusion and addition of two binding sequences, one each from E. coli and Acidithiobacillus ferrooxidans chromosome, in front of the R773 ArsR operon. Both of them were highly sensitive to arsenite, with a low detection limit of 0.04 µM arsenite (~ 5 µg/L). They showed a wide dynamic range of detection up to 50 µM using high copy number pLHPars9 and 100 µM using low copy number pLLPars9. Significantly, they differ in metal specificity, pLLPars9 more specific to arsenite, while pLHPars9 to both arsenite and antimonite. The only difference between pLHPars9 and pLLPars9 is their copy numbers of plasmid and corresponding ratios of ArsR to its binding promoter/operator sequence. Therefore, we propose a working model in which DNA bound-ArsR is different from its free form in metal specificity.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Plasmídeos
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Transativadores
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Genes Reporter
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Arsenitos
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Dosagem de Genes
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Proteínas de Escherichia coli
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Metais
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
Appl Microbiol Biotechnol
Ano de publicação:
2018
Tipo de documento:
Article
País de afiliação:
China