Structure of Chromophores in GFP-Like Proteins: X-Ray Data

The discovery of fluorescent proteins (FP) in 1962 and the following design of genetically encoded biomarkers and biosensors revolutionized the study of living systems. At present, researchers have access to FPs of a wide range of colors with a wide variety of specialized properties for visualization of biological processes in vivo using high-resolution spectroscopy techniques. GFP-like fluorescent proteins are widely used in cell biology as markers of various biological targets in a living cell. With the development of methods for visualizing processes in living organisms, the scientists have directed their efforts to designing new bright and photostable biomarkers of different colors with improved photophysical characteristics. The X-ray study plays an important role in design of the new biomarkers with improved properties. It allows us to determine the structure-function relations as a guide for directed change of the FPs properties meeting the requirements of modern research methods. The review presents the basic structures of the chromophores of the GFP-like fluorescent proteins determined by the X-ray method.