A nanoengine for gliding motility.

The terminal organelle present in some mycoplasma species is a very large, complex, flexible structure involved in cell adherence, motility and cell division. In this issue of Molecular Microbiology, Hasselbring and Krause report on a mutant in which the terminal organelle is only weakly connected to the rest of the cell. 'Run-away' terminal organelles first stretch the cells, then break away and continue moving independently for more than half an hour. This remarkable observation proves that the 'nanoengine' driving motility is indeed associated with the terminal organelle, and opens up new opportunities for dissecting and understanding its mechanism.