GEFs, GAPs, GDIs and effectors: taking a closer (3D) look at the regulation of Ras−related GTP−binding proteins

Cell biology depends on the interactions of macromolecules, such as protein−DNA, protein−protein or protein−nucleotide interactions. GTP−binding proteins are no exception to the rule. They regulate cellular processes as diverse as protein biosynthesis and intracellular membrane trafficking. Recently, a large number of genes encoding GTP−binding proteins and the proteins that interact witht these molecular switches have been cloned and expressed. The 3D structures of some of these have also been elucidate