The Goulding lab is building a systems-based perspective of aspects of Mycobacterium tuberculosis, informed by proteomic and crystallographic groundwork. Until recently, the focus of structural biology has been on single, isolated proteins. By focusing on molecular assemblies, we add an additional dimension to our molecular view of living systems. The utility of this approach is in yielding potential drug targets at the level of protein interactions, an approach inaccessible from an atomistic view of isolated proteins. Currently, we are focusing on host iron and heme uptake systems as iron is essential for M. tuberculosis along with metabolic enzymes that are required to maintain cell-wall integrity.