Acclimation of bacterial cell state for high-throughput enzyme engineering using a DmpR-dependent transcriptional activation system.
Sci Rep
; 10(1): 6091, 2020 04 08.
Article
in En
| MEDLINE
| ID: mdl-32269250
ABSTRACT
Genetic circuit-based biosensors have emerged as an effective analytical tool in synthetic biology; these biosensors can be applied to high-throughput screening of new biocatalysts and metabolic pathways. Sigma 54 (σ54)-dependent transcription factor (TF) can be a valuable component of these biosensors owing to its intrinsic silent property compared to most of the housekeeping sigma 70 (σ70) TFs. Here, we show that these unique characteristics of σ54-dependent TFs can be used to control the host cell state to be more appropriate for high-throughput screening. The acclimation of cell state was achieved by using guanosine (penta)tetraphosphate ((p)ppGpp)-related genes (relA, spoT) and nutrient conditions, to link the σ54 TF-based reporter expression with the target enzyme activity. By controlling stringent programmed responses and optimizing assay conditions, catalytically improved tyrosine phenol lyase (TPL) enzymes were successfully obtained using a σ54-dependent DmpR as the TF component, demonstrating the practical feasibility of this biosensor. This combinatorial strategy of biosensors using σ factor-dependent TFs will allow for more effective high-throughput enzyme engineering with broad applicability.
Full text:
1
Database:
MEDLINE
Main subject:
Bacterial Proteins
/
Tyrosine Phenol-Lyase
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Protein Engineering
/
Transcriptional Activation
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Trans-Activators
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High-Throughput Screening Assays
Language:
En
Journal:
Sci Rep
Year:
2020
Type:
Article