A light-responsive RNA aptamer for an azobenzene derivative

Area of Science:

• Synthetic Biology
• Molecular Biology
• Biochemistry

Background:

• Complex biological network regulation is a major challenge in synthetic biology.
• Riboswitches, utilizing RNA's structural flexibility, offer high specificity and efficiency for regulation.
• Synthetic riboswitches are valuable tools in synthetic biology applications.

Purpose of the Study:

• To develop a novel RNA aptamer that binds a small molecule ligand whose conformation is altered by light.
• To create a light-selective RNA binding system for potential use in engineered biological circuits.

Main Methods:

• Synthesis of a photoswitchable ligand (azoCm) by modifying azobenzene with chloramphenicol.
• Biophysical analysis of the ligand's stability and photoswitchability.
• In vitro selection to identify RNA aptamers specific to the ligand's trans photoisomer.
• Characterization of aptamer binding affinity and specificity.

Main Results:

• Successful development of an RNA aptamer with selective binding to the trans photoisomer of azoCm.
• Demonstrated binding affinity (KD) of 545 nM for the aptamer-ligand interaction.
• The aptamer does not bind the cis photoisomer, induced by 365 nm light, confirming light-selectivity.

Conclusions:

• A novel, light-selective RNA binding system has been engineered.
• This system utilizes an RNA aptamer and a photoswitchable ligand (azoCm).
• Potential for developing light-responsive riboswitches for advanced synthetic biology applications.