Intramolecular Autoregulatory Sequences in Proteins

Sa？etak The worldwide structural genomics initiative promises, within the next decade, to provide us with the three-dimensional structures of most representative proteins. However, the initiative does not in the initial stages specifically address the structural basis of protein-protein interactions and protein regulation, both of which are crucial for understanding the cellular function of proteins. This report reviews the studies of the structural basis of protein-protein interactions and regulation in several biologically important cellular processes carried out in our laboratory. The focus will be on the recognition of nuclear localization sequences (NLSs) by the nuclear import factor importin-α, and its regulation. Regulatory interactions in retroviral envelope proteins and the enzyme phenylalanine hydroxylase (PAH) will be discussed also. Ali three biological systems share a regulatory mechanism termed active sitedirected or intrasteric regulation