Engineering Approaches to Biomolecular Motors

Engineering Approaches to Biomolecular Motors: From in vitro to in vivo Wednesday Speaker Abstracts

Construction of a Synthetic Protein Motor Using a Covalent Self-Assembly System Roberta B. Davies 1 , Nancy R. Forde 2 , Dek N. Woolfson 3 , Heiner Linke 4 , Paul M. Curmi 5 . 1 Victor Chang Cardiac Research Institute, Darlinghurst, NSW, Australia, 5 University of NSW, Kensington, NSW, Australia. 2 Simon Fraser University, Burnaby, BC, Canada, 3 Bristol University, Bristol, United Kingdom, 4 Lund University, Lund, Sweden, Nanotechnology is emerging as a powerful field in the attempt to harness nature’s ability to work at the nanoscale through the use of protein machines. Working towards that end, considerable advances have been made in the construction of small molecule and DNA-based motors, however construction of synthetic protein based assemblies with motor properties is still in its infancy. We present what is likely to be the first synthetic protein motor construction derived from non- motor protein components. These have been produced from DNA templates by expression in bacteria. Components have been designed to spontaneously self assemble into covalently linked branched protein structures capable of binding specific DNA sequences dictated by particular ligands. Ultimately these assemblies will be tested for their ability to move along a DNA track bearing repeats of the specific DNA sequences required for binding by the protein modules. Movement will be controlled by supply of ligands using microfluidic devices. Conformational Switching as a Driving Force for Designed Motors Elizabeth Bromley 1 , Lara Small 1 , Asahi Cano-Marques 1 , Richard Sessions 2 , Martin Zuckermann 3 . 1 University of Durham, Durham, United Kingdom, 2 University of Bristol, Bristol, United Kingdom, 3 Simon Fraser University, Vancouver, BC, Canada. Conformational switching is an important component of the operation of most biological motors, and can play a significant role in the processivity and speed with which such motors move. We have chosen to explore the function of nanoscale motors via the design of synthetic motors made from biomimetic components. One such motor design is the bar-motor, a bipedal motor designed to walk along an asymmetric DNA-based track. The motor comprises two ligand gated DNA binding domains linked by a coiled-coil segment. This motor would be expected to step randomly via the cyclic addition of ligands, however, processive motion can be encouraged via the introduction of a power stroke in which the conformation of the coiled coil is coupled to the ligand cycle. In this work we use multiscale modelling to predict the function of a motor with the ascribed properties. We then explore the design of the coiled-coil region in relation to its ability to undergo conformational switching once coupled to a photosensitive azobenzene unit. We further present experimental data on the performance of various coiled-coil-azobenzene designs on exposure to light.

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