Directional control of a processive molecular hopper

Abstract

Tiny cargos ferried along a track Control of molecules at the nanometer scale requires motors that convert potential energy into movement. Qing et al. designed a small molecule that could hop along a track of cysteine residues within a membrane-embedded protein pore. The direction of processive movement along the track was reversible, driven by an applied potential across the membrane. Cargos were attached to a carrier motor, and their position and chemical identity read out from changes in the current through the pore. These features enabled repeat observations of a single molecule as it moved back and forth on the track. Science , this issue p. 908