Our interest is in ABC membrane proteins, products of the largest family of genes known to code for proteins mediating translocation of solutes across biological membranes in all forms of life. Of the 48 recognized in the human genome nearly twenty are involved in human disease including at least three that are major contributors to the failure of cancer chemotherapy due to resistance to anti-neoplastic drugs. Most of our research is focused on an ABC protein mutated in patients with cystic fibrosis, ie. ABCC7 or CFTR. Because its conformational maturation and intracellular trafficking is defective in most patients we are attempting to completely elucidate and manipulate the underlying mechanisms. Other efforts include characterization and integration of the enzymatic and ion channel activities of the protein and determination of its 3D structure. A low resolution structure has been obtained from 2D crystalline arrays of the purified protein and 3D crystallization trials are proceeding to enable X-ray diffraction and atomic resolution.