Molecular Propulsion: Chemical Sensing and Chemotaxis of DNA Driven by RNA Polymerase

摘要

RNA polymerase (RNAP) is one of the best characterized motor proteins which transcribes on a DNA template while presenting unique motor properties. The powerful tracking ability of RNAP underlies devices supporting nanoscale motion control on planar substrates. Nevertheless existing experimental systems that track protein motor activities are restricted to tethering the substrate or the motor and, therefore, cannot support observation of autonomous movement modulated by the motor in free solution. Although autonomous control has been reported by metallic, reactive colloids, it has not been demonstrated with biomolecules under physiological conditions. Here we show the first experimental evidence that a molecular complex consisting of just a DNA template and associated RNAPs displays chemokinetic motion driven by transcription substrate NTPs. Furthermore this molecular complex exhibits biased migration into a concentration gradient of NTPs for mimicking cellular chemotaxis.