PT - JOURNAL ARTICLE AU - Chazin, Walter J. TI - The Impact of X-ray Crystallography and NMR on Intracellular Calcium Signal Transduction by EF-Hand Proteins: Crossing the Threshold from Structure to Biology and Medicine AID - 10.1126/stke.3882007pe27 DP - 2007 May 29 TA - Science's STKE PG - pe27--pe27 VI - 2007 IP - 388 4099 - http://stke.sciencemag.org/content/2007/388/pe27.short 4100 - http://stke.sciencemag.org/content/2007/388/pe27.full SO - Sci. STKE2007 May 29; 2007 AB - The use of x-ray crystallography and solution nuclear magnetic resonance (NMR) spectroscopy has revolutionized our understanding of the transduction of intracellular calcium signals into cellular responses. Indeed, the ability to cross a critical threshold from basic descriptive structural biochemistry to real-world applications in therapeutics and biotechnology now looms on the experimental horizon. The ~500 atomic resolution structures determined by x-ray and NMR approaches and deposited in the Protein Data Bank, many of which are of complexes of EF-hand proteins with peptide fragments of cellular targets, have yielded an extremely thorough description for how EF-hand proteins respond to the binding of calcium. Although this database of structures is a powerful structural tool to describe EF-hand protein function, it is limited in its ability to have a significant impact on biology and medicine because the structural effects on the downstream target are not determined. The opportunity that now lies before us is to extend this EF-hand–centric structural information so that the alterations in the target proteins are defined and the structural basis for functional consequences downstream is understood.