A DNA Bubble-Mediated Gene Regulation System Based on Thrombin-Bound DNA Aptamers

Area of Science:

• Molecular Biology
• Biotechnology
• Synthetic Biology

Background:

• Cell-free gene expression systems offer a controllable environment for studying biological processes.
• Enhancing transcription efficiency is crucial for optimizing synthetic gene circuits and protein production.
• Aptamers, short nucleic acid sequences, can bind specific targets and modulate molecular interactions.

Purpose of the Study:

• To develop a novel strategy for enhancing gene transcription in cell-free systems.
• To investigate the mechanism of aptamer-mediated gene regulation via promoter modulation.
• To demonstrate the efficacy of the proposed system in boosting target gene expression.

Main Methods:

• Symmetrically introducing duplex aptamers upstream of the T7 promoter on both sense and antisense strands of double-stranded plasmids.
• Inducing a DNA bubble formation due to non-complementary aptamer sequences.
• Utilizing thrombin binding to aptamers to enlarge the DNA bubble.
• Assessing gene expression levels of GFP and EcaA in cell-free systems.

Main Results:

• The novel aptamer-based system successfully enhanced target gene transcription in cell-free systems.
• Enlargement of the DNA bubble by aptamer-thrombin interaction improved RNA polymerase binding and promoter recognition.
• Increased DNA unwinding efficiency contributed to higher transcriptional output.
• Demonstrated enhanced expression of reporter genes (GFP) and functional genes (EcaA).

Conclusions:

• The developed method provides an effective means to enhance gene transcription in cell-free expression platforms.
• Aptamer-mediated modulation of promoter accessibility offers a new paradigm for gene regulation.
• This approach holds potential for applications in synthetic biology, protein engineering, and diagnostics.