Pathogenic bacteria have an arsenal of surface and secreted proteins that allow them to conquer the many unique niches they occupy throughout the course of infection. Most of these proteins are related both structural and functional to their eukaryotic counterparts. In particular some bacteria have hijacked some eukaryote specific proteins to aid in bacterial pathogenesis This proposal will investigate the structure and function of ecto-nucleoside triphosphate diphosphoydrolases (NTPDases) from Legionella. The outcomes of this proposal will aid in understanding the mechanism of a microbial NTPDases with the potential to develop novel antimicrobials.