Synthetic DNA Promoters to Control Gene Expression Based on the Presence of Oxygen in E. coli
Open Access
Author:
Kirk, Andrew
Area of Honors:
Biological Engineering
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
Dr. Howard M Salis, Thesis Supervisor Ali Demirci, Thesis Honors Advisor
Keywords:
synthetic biology genetic engineering E. coli DNA oxygen-sensitive promoters ArcA FNR dcuC
Abstract:
A catalogue of synthetic σ70 promoters incorporating oxygen-sensitive transcription factors was designed, and the promoters were tested in E. coli. Two known oxygen-dependent transcription factors were utilized in the design of the synthetic promoters: fumarate-nitrate-reduction (FNR), and ArcA (1). The synthetic promoters were based on four distinct promoter templates: the dicarboxylate carrier (dcuC) gene that contains FNR naturally in E. coli (2), a synthetic promoter called J23113 from the Registry of Standard Biological Parts (3), the thiol peroxidase (tpx) gene that naturally contains ArcA in E. coli (4), and the tpx gene with a modified consensus Pribnow box at the -10 region of the σ70 promoter. The FNR promoters based on the natural dcuC gene were found to induce protein expression the most under anaerobic conditions; however an FNR promoter based on the entirely synthetic promoter J23113 was found to have a response within a similar range of values. The ArcA promoters based on the natural tpx gene were found to have a very low induction and even exhibited some repression in anaerobic conditions, while the ArcA promoters based on a tpx gene modified to incorporate the consensus Pribnow box at the -10 of the σ70 site were found to exhibit very low induction but no repression.