Speaker Professor Jan Löwe, Director, MRC Laboratory of Molecular Biology, University of Cambridge 

Title Prokaryotic Cytoskeletons

Host Julien Bergeron

 

Abstract Like their eukaryotic counterparts, bacteria and archaea depend on filaments to organise their cells. Since the discovery of FtsZ over 30 years ago, a plethora of actin-like, tubulin-like and intermediate filament-like polymers have been found and investigated.

I will describe our current understanding of how some of these prokaryotic cytoskeletons function in cell division, cell shape determination, DNA segregation and beyond. I will point out how we think they evolved during evolution into eukaryotic F-actin and microtubules. The path is less clear for intermediate filaments and I will discuss our recent structure of crescentin that illuminates its evolutionary relationship with them.

Finally, a survey of all available structures of the filamentous proteins reveals that a conformational switch during the polymerisation process is required to make in-built, nucleotide hydrolysis-driven filament dynamics such as treadmilling useful in cells. The cytomotive switch is required to link filament polarity with hydrolysis direction and is universal.