Structure and fluorescence mechanism of GFP

The crystallographic findings of Yang, Moss, and Phillips and the work of two independent teams of femtosecond spectroscopists now provide us with the information to understand the nature of the absorption and emission phenomena of green fluorescent protein (GFP). These phenomena relate the atomic resolution structure of GFP to the first known example of a Forster cycle within the core of a protein--another big surprise from this most unusual protein.