Protein complex formation during starch digestion in the human microbiome
Event details
| Date | 26.07.2016 |
| Hour | 12:15 |
| Speaker |
Dr. Hannah Tuson, Department of Chemistry, University of Michigan Bio: I am using single-molecule fluorescence microscopy to examine the localization and dynamics of proteins in live bacteria. I work primarily in three biological systems: 1. the starch utilization system (Sus) in the human gut bacterium Bacteroides thetaiotaomicron, which binds to and degrades starch; 2. the proteins involved in replication restart after fork collapse in Bacillus subtilis; and 3. the TonB-dependent iron importer FhuA in Escherichia coli. |
| Location | |
| Category | Conferences - Seminars |
Bacteroides thetaiotaomicron is one of the most abundant inhabitants of the mammalian gut. This obligate anaerobe unlocks nutrients from our diet via the catabolism of host indigestible carbohydrates. This process occurs via substrate-specific polysaccharide utilization systems, of which the best studied is the Starch Utilization System (Sus). Sus includes five outer membrane proteins: SusDEF cooperate to bind large starch molecules, which SusG degrades into smaller oligosaccharides for transport to the periplasm through the SusC porin. We have examined the dynamics of SusG in live B. thetaiotaomicron cells with single-molecule fluorescence microscopy and tracking, and found that the dynamics of SusG are altered in the presence of starch. We are now extending our studies to fluorescently labeled SusE and SusF in order to directly probe the assembly dynamics of the full Sus complex. We show that both SusE-PAmCherry and SusF-PAmCherry are essentially stationary in the membrane, even when other members of the Sus complex are absent. Additionally, we show that mobile SusG often co-localizes with stationary SusE and SusF. This research will allow us to better understand the role of the Sus proteins in starch breakdown by symbiotic bacteria during normal human digestion, as well as to discern the process of carbohydrate metabolism by gut bacteria in general.
Practical information
- Informed public
- Free
Organizer
- GHI Floor Seminars, Prof. Melanie Blokesch