Fly-fishing for flagella: Molecular grappling hooks are the tools of a sticky bacterial predator

Predators loom large in the public consciousness, with nature documentaries feeding a fascination for the different ways in which animals hunt and kill one another. Where a resource (food) exists, nature will find a way to exploit it. This is no different at the microscopic level, and although study of microbial predation is much less common, there are several model predatory bacteria. These include Bdellovibrio bacteriovorus, a bacterium that invades the periplasm of Gram-negative bacteria, and Myxococcus xanthus, a predator capable of both single-cell, contact-dependent killing and multicellular “wolf pack” behavior involving coordinated movement of a group of predator cells. On page 288 of this issue, Lien et al. (1) report the molecular basis for ixotrophy, another mode of bacterial predation whereby gliding multicellular filamentous Aureispira deploy “grappling hooks” to catch Vibrio prey by their flagella.