Structure–function relationships in fluorescent marker proteins of the green fluorescent protein family

GFP-like proteins, originally cloned from marine animals, are genetically encoded fluorescence markers that have become indispensable tools for the life sciences. The search for GFP-like proteins with novel and improved properties is ongoing, driven by the persistent need for advanced and specialized fluorescence labels for cellular imaging. The 3D structures of these proteins are overall similar. However, considerable variations have been found in the covalent structures and the stereochemistry of the chromophore, which govern essential optical properties such as the absorption/emission wavelengths. A detailed understanding of the structure and dynamics of GFP-like proteins greatly aids in the rational engineering of advanced fluorescence marker proteins. In this chapter, we summarize the present knowledge of the structural diversity of GFP-like proteins and discuss how structure and dynamics govern their optical properties