Recent work has focused on obtaining a better understanding of the three-dimensional structural relationships between the alpha and beta subunits of the F1 moiety and the location of nucleotide binding domains within these subunits. Four types of approach are currently being pursued: X-ray crystallographic, chemical, molecular biological and biochemical. Here we briefly review some of the major conclusions of these studies, and point out some of the problems that must be resolved before an adequate model that relates structure to function in the ATP synthase molecule can be formulated.