Internal Seminar: Shannon Unit and Wolf Unit

Join us for September's first Internal Seminar Series on September 4, from 17:00 to 18:00 in C700 (Lab3). This month's first seminar features the Theory of Quantum Matter Unit (Nic Shannon) and the Molecular Cryo-Electron Microscopy Unit (Matthias Wolf).

Theory of Quantum Matter Unit (Nic Shannon)

Speaker : Owen Benton

Title : Is ice a quantum liquid?

Abstract : Ice is one of the most ubiquitous and one of the most mysterious materials on Earth, displaying at least 17 different crystal structures. In the most common form of ice (ice Ih) the oxygen ions form an ordered lattice while the protons remain disordered- in flat contradiction with the ordinary picture of solids. The disordered proton configurations are governed by strong constraints (the "ice rules") and the conventional wisdom would have it that at low temperatures the protons are trapped in a single configuration, unable to move without violating those constraints. However, recent experiments have called this into question, suggesting that the protons can remain mobile by collective quantum tunnelling. Here we will discuss the consequences of this quantum tunnelling, including the intriguing possibility that the protons in ice Ih could form a quantum liquid at low temperatures, in which they are not merely disordered but continually fluctuate from one state to another.

Molecular Cryo-Electron Microscopy Unit (Matthias Wolf)

Speaker : Molecular Indiana Jones (aka Izaak Coleman)

Title : Uncovering the history of a biological nanomachine: Using structural biology to supplement phylogenetics.

Abstract : The bacterial flagella motor is an intricate biological nanomachine that functions as a rotary motor, generating torque for bacterial motility. By use of Electron Cryo-Tomography, it has become apparent that this nanoscale motor has undergone extensive molecular evolution, whereby structural ‘mods’ in the form of additional protein subunits have been incorporated onto the highly conserved core structure of the motor. Interestingly, this has lead to structural and functional diversification of the motor across the bacterial taxa, resulting in increased torque output, alternative fuel types, and motors reaching rotational speeds in excess of 100’000rpm.
During my undergrad, in order to gain better insight into the bacterial flagellar motors evolutionary history, I performed phylogenetic analysis of the conserved core motor structure. In doing so, I identified a number of interesting evolutionary events involving both the core motor structure, and the numerous modifications. During my OIST internship, I have focused on one specific event in the flagellar motors evolutionary history, in which a group of gamma-proteobacteria, including the model species’ Salmonella enterica and Escherichia coli, acquired their flagellar motor from a distant beta-proteobacteria donor. I am using the technique of Electron Cryo-Tomography to provide structural evidence for this event, backing up the phylogenetic evidence.