Repurposing a macromolecular machine: Architecture and evolution of the F7 chemosensory system
How complex, multi-component macromolecular machines evolved remains poorly understood. We will discuss the evolutionary origins of the chemosensory machinery that controls flagellar motility in Escherichia coli. We first identified ancestral forms still present in Vibrio cholerae, Pseudomonas aeruginosa, Shewanella oneidensis and Methylomicrobium alcaliphilum, characterizing their structures by electron cryotomography and finding evidence that they function in a stress response pathway. Using bioinformatics, we then traced the evolution of the system through γ-Proteobacteria, pinpointing key evolutionary events that led to the machine now seen in E. coli. Our results suggest that two ancient chemosensory systems with different inputs and outputs (F6 and F7) existed contemporaneously, with one (F7) ultimately taking over the inputs and outputs of the other (F6), which was subsequently lost.
Date: 22 July 2019, 11:30 (Monday, 13th week, Trinity 2019)
Venue: Dorothy Crowfoot Hodgkin Building, off South Parks Road OX1 3QU
Venue Details: Main Seminar Room
Speaker: Davi Ortega (Caltech, Grant Jensen Lab)
Organising department: Department of Biochemistry
Organiser: Dr Phillip Stansfeld (University of Oxford)
Organiser contact email address: jolanta.parkinson@bioch.ox.ac.uk
Host: Dr Phillip Stansfeld (University of Oxford)
Topics:
Booking required?: Not required
Audience: Members of the University only
Editor: Jolanta Parkinson