Wednesday, 2 August 11:00am – 12:00pm

This seminar will be delivered in Chemistry Lecture Theatre 4 and Online (Zoom) Please email chemistry.researchsupport@sydney.edu.au for zoom link and password.

Speaker: A/Prof. Matthew Baker, University of New South Wales

Host: Dr Constance Bailey

Title: Ask the ancestors: how did you swim in YOUR day? Synthetic biology of molecular motors from both the top down and the bottom up.

Abstract: Matthew Baker works on two systems of biophysical interest: 1) the bacterial flagellar motor, a rotary electric nanomachine which powers most bacterial swimming, and 2) using de novo DNA nanotechnology to control and shape lipid membranes. The flagellar motor is one of the canonical molecular complexes, ~40 nm in diameter but capable of rotating at 1000 Hz, self-assembling in the membrane and changing rotational direction in milliseconds. His team’s recent work on the flagellar motor used directed evolution to monitor the adaptation of the stator units, the engine which drives rotation, in changing environments to explore what constrains the operation and evolution of the motor. The structure of the stator was recently solved, hinting that the stators themselves are an even tinier rotating nanomachine! This has dramatically changed our approaches to stator engineering, as well as revolutionised the study of motor biophysics, where many tiny ‘wheels’ in turn engage the larger rotor and ultimately the bacterial filament which enables cellular propulsion.

At the other end of the scale, from the in vitro bottom-up perspective, we look at how to build multi-compartment interacting systems out of simple DNA and lipid components. Our work on DNA nanostructures, in collaboration with Dr Shelley Wickham’s team at Sydney University, has recently characterised the best conditions to get DNA nanostructures and lipids to work together. Typically, DNA nanostructures use cholesterol moieties to embed in the membrane but a full characterisation of the best way to connect and arrange these cholesterols was previously lacking. We have recently demonstrated that more cholesterols are not necessarily better and explored the most suitable linkage chemistry to allow strand displacement, the basis of all reaction and interaction in DNA nanotechnology.

Bio: Matt grew up in Dunedin, New Zealand, and finished an Hons in Chemistry at the Australian National University studying Fluctuation Theorems before completing his DPhil in Physics at the University of Oxford as a John Monash Scholar looking at the molecular motor that makes many bacteria swim. He finished a postdoc on protein transport in the Department of Biochemistry and then returned to study structural biology at the Victor Chang Cardiac Research Institute in Sydney, Australia. Matt focused primarily on how simple subunit interactions govern assembly of complex architectures, including the rotor (NSMB 2016) and filament (eLife 2017) of the bacterial flagellar motor. Matt’s group at UNSW Sydney continue to study the flagellar motor, focusing on ion selectivity changes using directed evolution and ancestral reconstruction (Mol Micro 2019, Front. Microbiol. 2020, Microlife 2023) to examine the evolutionary landscape that constrains the adaptation of the motor (Science Advances 2022). We then use this knowledge to examine other potential applications of the flagellar motor (Journal of Bacteriology 2021, Biomicrofluidics 2020, Biomicrofluidics 2023).

Matt’s team also investigate force sensitive proteins that in synthetic lipid bilayers (Channels 2019). In collaboration with Dr Shelley Wickham, we probe membrane dynamics and interactions using novel DNA nanotechnology (Nanoscale 2019, NAR 2021), with the ultimate goal to control membrane communication using de novo DNA nanotechnology.

Matt loves radio: he was a Top 5 Under 40 Scientist in Residence at the ABC in 2015 and a regular correspondent on Nightlife on the ABC for a few years. He still discusses science news approximately monthly on Koori FM in Sydney and on Saturday Morning on Radio New Zealand.