DNA Motors Powered by Exonuclease III for Autonomous Rolling Motion and Biosensing Applications

Area of Science:

• * Nanotechnology and synthetic biology
• * Enzyme-powered molecular machines

Background:

• * Nucleic acid-based synthetic motors mimic biological machines for biosensing and actuation.
• * Existing RNase H-powered motors are fast but unstable due to RNA fuel dependence.

Purpose of the Study:

• * To develop a robust, RNA-free DNA motor for enhanced stability and broader applications.
• * To explore the mechanism and optimize performance of Exonuclease III-powered DNA motors.

Main Methods:

• * Designed and synthesized DNA motors powered by Exonuclease III.
• * Utilized fluorescence and brightfield microscopy to observe motor dynamics.
• * Optimized motor performance by tuning reporter chemistry, DNA sequences, and fuel density.

Main Results:

• * Demonstrated a self-avoiding rolling motion driven by DNA hydrolysis, consistent with a burnt-bridge Brownian ratchet mechanism.
• * Observed super-diffusive and Lévy-like stop-and-go dynamics under optimized conditions.
• * Achieved RNase resistance due to the DNA-only architecture.

Conclusions:

• * Established a chemically stable, tunable, and biosensing-compatible DNA motor platform.
• * Showcased the potential for motion-based biosensing using aptamer-functionalized components.
• * Highlighted the modularity and expanded scope of rolling motor platforms with enzymatic diversity.