Type IV Pili - multifunctional surface filaments
Many species of bacteria produce long, thin, flexible protein filaments called type IV pili (T4P). These fascinating appendages can be rapidly and repeatedly extended and retracted, allowing the bacteria to use them to capture DNA (like a spear-fishing rod) or to crawl on surfaces (like a grappling hook). They are adhesive, allowing bacteria to stick to all kinds of different surfaces, including the host in the case of pathogens. Bacteria use them to 'feel' surface contact, which then turns on expression of surface-associated genes such as those involved in biofilm formation. They are receptors for bacteriophages (viruses that specifically kill bacteria) and in some species, can even act as wires to conduct electricity!
We study multiple aspects of these amazing filaments. Ongoing projects range from studying the structure and function of the machine that makes the filaments, the motor that extends and retracts them, the diversity of the subunits that make up the filaments and its relationship to phage escape, the regulatory pathways involved in surface sensing, and more!