Mechanics and function of force generation by bacterial pili
Claudia Holz, Rainer Kurre, and Kanimozhi Ramakrishnan
Type IV pili are molecular motors that mediate bacterial surface motility. Like grappling hooks, these polymers cooperate for generating bacterial movement. Pili are multifunctional polymers that are essential not only for motility, but also for adhesion to surfaces, virulence, and horizontal gene transfer.
We have used laser tweezers to show that type IV pili can generate forces exceeding 100pN, making pili the strongest linear motors characterized so far. Currently, we are investigating how force generation can be controlled by environmental inputs. To this end, we use a combination of methods from biophysics and genetics. Our model bacteria include the human pathogen Neisseria gonorrhoeae and the soil-dweller Myxococcus xanthus.
The dynamics of type IV pili is important for controlling the architecture of bacterial biofilms. Within these large communities bacteria can communicate and even share tasks. We developed a method for controlling the nucleation of such bacterial clusters by using the method of microcontact printing. On a surface with varying physico-chemical properties, bacterial movement can be guided and the formation of microcolonies can be controlled.
Techniques
- Laser tweezers
- Microcontact printing
- Molecular cloning
- Surface analytics
Collaborations
Michael Koomey, Oslo University
Lotte Søgaard-Andersen, Max Planck-Institut Marburg
Bart Jan Ravoo, Westfälische Wilhelms-Universität Münster
Publications
- Kurre, R., Maier, B. Oxygen Depletion Triggers Switching between Discrete Speed Modes of Gonococcal Type IV Pili, Biophys. J., 102(11), 2556 (2012)
Meel, C., Kouzel, N., Oldewurtel, E.R., Maier, B. Three-Dimensional Obstacles for Bacterial Surface Motility, Small, 8(4), 530 (2012)http://www3.interscience.wiley.com/journal/122213601/abstract
Allemand, J.-F., Maier, B., Smith, D.E. Molecular motors for DNA translocation in procaryotens, Curr. Opin. Biotechnol., accepted
Holz, C., Opitz, D., Greune, L., Kurre, R., Koomey, M., Schmidt, M.A., Maier, B. Multiple pilus motors cooperate for persistent bacterial movement in two dimensions. Phys. Rev. Lett. 104(17), 178104 (2010)http://www.cell.com/biophysj/retrieve/pii/S0006349508000878
- Holz, C., Opitz, D., Mehlich, J., Ravoo, B.J., Maier, B. Bacterial motility and clustering guided by microcontact printing. Nano Lett. 9(12), 4553-4557 (2009)
Allemand, J.-F., Maier, B. Bacterial translocation motors investigated by single molecule techniques, FEMS Mircobiol. Rev. (2009)
- Bulyha, I., Schmidt, C., Lenz, P., Jakovljevic, V., Höne, A., Maier, B., Hoppert , M., Søgaard-Andersen, L. Regulation of the type IV pili molecular machine by dynamic localization of two motor proteins. Mol. Microbiol. 74(3), 691-706 (2009)
- Clausen, M., Jakovljevic, V., Søgaard-Andersen, L., Maier, B. High force generation is a conserved property of type IV pilus systems. J. Bacteriol. 191(14), 4633-4638 (2009)
Clausen, M., Koomey, M., Maier, B. Dynamics of type IV pili is controlled by switching between multiple states. Biophys. J. 96(3), 1169-1177 (2009)
Winther-Larsen, H.C., Wolfgang, M.C., van Putten, J.P.M., Roos, N., Aas, F.E., Egge-Jacobsen, W.M., Maier, B., Koomey, M. Pseudomonas aeruginosa Type IV Pilus Expression in Neisseria gonorrhoeae: Effects of Pilin Subunit Composition on Function and Organelle Dynamics. J. Bacteriol. 189(18), 6676-6685 (2007)
Maier, B. Manipulation of single molecules in living bacteria. Microbe 1(7), 330-336 (2006)
Maier, B. Using laser tweezers to measure twitching motility. Curr. Opin. Microbiol. 8(3), 1-6 (2005)
Maier, B., Koomey, M., and Sheetz, M.P. A force-dependent switch reverses type IV pilus retraction. Proc. Natl. Acad. Sci. USA 101(30), 10961-10966 (2004)
Maier, B., Potter, L., So, M., Long, C.D., Seifert, H.S., Sheetz, M.P. Single pilus motor forces exceed 100pN. Proc. Natl. Acad. Sci. USA 99(25), 16012-16017 (2002)