Our laboratory seeks to understand how cells move one of the largest and most hydrophilic biological molecules across hydrophobic membrane barriers. In bacteria alone, this process is involved in the transfer of antibiotic resistance, spore formation, and proper chromosome segregation during growth. Yet, very little is known about the molecular mechanism of DNA translocation across membranes in any system, as tools to study the mechanism of DNA transporters in their biological context at the membrane have been lacking. We combine in vitro and in vivo biochemistry, microscopy, microbiology and molecular biology to study these DNA transport complexes.