title: "Four-dimensional" protein structures: examples from metalloproteins.
abstract: The fact that an object, for example, a protein, possesses a three-dimensional structure seems an obvious concept. However, when the object is flexible, the concept is less obvious. Growing experimental data over several decades show that proteins are not rigid objects, but they may sample more or less wide ranges of different conformations. To stress this concept, we propose to call the range of sampled conformations the "fourth dimension" of the protein structure. Nuclear magnetic resonance is a precious technique to define this fourth dimension. Examples of conformational heterogeneity taken from the realm of metalloproteins and their functional implications are discussed.
authors.affiliation: Centro Risonanze Magnetiche (CERM) and Department of Agricultural Biotechnology, University of Florence, Via Luigi Sacconi, 6, 50019 Sesto Fiorentino (Florence), Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Fragai
authors.forename: Claudio
authors.initials: C
authors.lastname: Luchinat
authors.forename: Giacomo
authors.initials: G
authors.lastname: Parigi
mesh_terms: D003300:Copper / Q000737:chemistry; D008667:Metalloproteins / Q000737:chemistry*; D008958:Models, Molecular; D011487:Protein Conformation; D015398:Signal Transduction
chemical_list: D008667:Metalloproteins; D003300:Copper