Institut de Biologie StructuraleGrenoble / France


NMR a tool to detect ultraweak interactions in proteins

Usually, weakly polar CH/pi interactions are inferred from the three-dimensional coordinates of proteins. The researchers of IBS in collaboration with groups of York and Ottawa universities, used solution nuclear magnetic resonance (NMR) spectroscopy in tandem with an optimized methyl (Me) isotope labeling strategy to directly observe Me/pi interactions between Methyl groups and backbone atoms of proteins. Based on the results of density functional theory (DFT) calculations and NMR spectra, the researchers provide compelling evidence of Me/pi interactions in proteins and describe how simple and unambiguous assignment of donor and acceptor groups of CH-pi pairs can be achieved. Thus, the need for an a priori knowledge of the three-dimensional structure of a protein is obviated for characterization of these weak interactions on an individual basis.

Observation of CH⋅⋅⋅π Interactions between Methyl and Carbonyl Groups in Proteins. Perras FA, Marion D, Boisbouvier J, Bryce DL, Plevin MJ. Angewandte Chemie-International Edition England doi: 10.1002/anie.201702626

Protein dynamics in the crystal : a subtle balance of inter- and intramolecular contacts

Recent advances in crystallographic techniques allow to obtain not only a single static picture of proteins – which are those that fill the protein data bank – but they also reveal the dynamics of protein around these « snapshots ». Knowledge of these motions may be a key to understanding protein function. But an important question remained so far poorly understood : are the protein motions in the crystal lattice representative of those in the actual biological environment ? Kurauskas et al. have combined novel solid-state NMR techniques and multi-microsecond MD simulations to reveal, for the first time, how the crystal packing influences protein dynamics on the biologically important time scale of micro/milliseconds, and lays the ground for future crystallography-based studies of protein dynamics.

Slow conformational exchange and overall rocking motion in ubiquitin protein crystals. Kurauskas V, Izmailov SA, Rogacheva O, Hessel A, Ayala I, Woodhouse J, Shilova A, Xue Y, Yuwen T, Coquelle N, Colletier JP, Skrynnikov NR, Schanda P. Nature Communications DOI:10.1038/10.1038/s41467-017-00165-8

How plankton dominate ocean life

Photosynthesis is a unique process that allows independent colonization of the land by plants and of the oceans by phytoplankton. Although the photosynthesis process is well understood in plants, scientists are still unlocking the mechanisms evolved by phytoplankton to achieve extremely efficient photosynthesis. Researchers from the Institut de Biosciences et Biotechnologies de Grenoble (BIG), the Institut de biologie structurale (IBS), the Institut nanosciences et cryogénie (INAC), the Institut de Biologie Physico-Chimique (IBPC), ETH Zurich (Switzerland) and University of Konstanz (Germany), combine biochemical, structural and in vivo physiological studies to unravel the structure of the plastid in diatoms, prominent marine eukaryotes. The results of this study were published in Nature Communications on June 20, 2017.

Communiqué/Press release

Plastid thylakoid architecture optimises photosynthesis in diatoms. Flori S, Jouneau PH, Bailleul B, Gallet B, Estrozi LF, Moriscot C, Bastien O, Eicke S, Schober A, Río Bártulos C, Maréchal E, Kroth PG, Petroutsos D, Zeeman S, Breyton C, Schoehn G, Falconet D and Finazzi G. Nature Communications;8:15885.