On-Demand Photoactivation of DNA-Based Motor Motion.

A major challenge in the field of synthetic motors relates to mimicking the precise, on-demand motion of biological motor proteins, which mediates processes such as cargo transport, cell locomotion, and cell division. To address this challenge, we developed a system to control the motion of DNA-based synthetic motors using light. DNA motors are composed of a central chassis particle modified with DNA "legs" that hybridize to RNA "fuel", and move upon enzymatic consumption of RNA. We first concealed RNA fuel sites using photocleavable oligonucleotides that block DNA leg binding. Upon UV activation, the RNA blocking strands dissociate, exposing the RNA fuel and initiating active, directional motion. We also created a "brake" system using photocleavable DNA stalling strands, anchoring the motors until UV light removes the "brake" while simultaneously "fueling" the motors, initiating spatiotemporally controlled stop → go motion. Additionally, we modified the "brake" system to activate the motors via a chemical input, while an optical input is required to fuel the motors. This dual-input approach, functioning as an "AND" gate, demonstrates the potential for DNA motors to perform light-triggered computational tasks. Our work provides a proof of concept for enhancing the complexity and functionality of synthetic motors.