Peter S. Kim

My laboratory has developed the use of coiled coils as model systems for studying protein-protein interactions. The coiled-coil is a type of protein structure consisting of two or more alpha-helices that wrap around one another. We recently estimated that three percent of protein sequences correspond to coiled coils, suggesting that these types of interactions will be central to many aspects of biology. Our interest in the coiled-coil motif led us to uncover a "spring-loaded" mechanism for membrane fusion by the influenza virus. In this mechanism, a structural transition within the viral membrane-fusion protein propels a hydrophobic "fusion-peptide" region of the protein toward the cell membrane, in a harpoon-like manner. Recently we found that the membrane-fusion proteins from two other viruses, including HIV, have structures that are very similar to that found in influenza, suggesting a common membrane-fusion mechanism for these diverse viruses. My laboratory also has an interest in protein folding. Our results support simple, hierarchical models for the folding process, in which intermediate stages have the same basic structural elements as the finished product. More recently, we have been using protein design as a test of our knowledge of protein folding.