*Living deep: Structural basis of piezophilic adaptation* ELMA group. Institut de Biologie Structurale J.-P. Ebel -- Grenoble -- France http://www.ibs.fr/groupes/groupe-extremophiles-et-grands/ We are recruiting a post-doctoral scientist interested in life adaptation to extreme conditions. The position is for 2 years and is funded by the french national agency for research (ANR) A high-pressure environment characterizes our planet. For more than 60 % of the biosphere pressure is greater than 100 bars and it can reach 1000 bars in the deepest sea trenches, like the Marianna's trench. However, in these extreme conditions, a vast biodiversity of adapted micro-organisms (piezophiles) can be encountered. So far, the molecular mechanisms that facilitate proteins function under high pressure remain obscurs. Beside interests to understand fundamental protein folding processes and life evolution, this information is essential to develop biotechnological application from deep sea enzymes. This work will be performed in the framework of a collaborative network including ENS Lyon and IFREMER-UBO in Brest in which a new archaeon from the Pyroccoccus phylum was recently discovered and was called Pyrococcus yayanosii CH1. This microbe is the first obligate piezophile as it is only able to grow under pressure (optimal growth: 98°C and 520 bars). The project is based on the study of two protein families, for which the biochemistry is well handled by the team: large peptidases complexes and lactate/malate dehydrogenase (LDH/MalDH). These proteins play key roles in metabolic adaptation to deep sea ecosystem and allow combining structural approaches (protein crystallography, small-angle scattering...) and biochemical approaches (oligomer stability, enzymatic activity measurements...). The candidate will study the molecular effects of high pressure/temperature by comparing the structural and functional properties of different proteases and LDH/MalDH from Thermococcus and Pyrococcus phylums (including Pyrococcus yayanossi CH1) isolated at various water depths. The ELMA team possesses a fully-fledged wet laboratory for all biochemical steps and the project will benefit from privileged access to large facilities (synchrotron and neutron sources) as well as from latest developments in high-pressure biophysics: high-pressure protein crystallography, for which the ELMA team is a world leader, small-angle x-ray scattering under high-pressure, UV-Visible spectrophotometer and fluorimeter both equipped with a high-pressure vessel. The candidate should have a background in biochemistry with a strong interest in structural approaches or a physico-chemistry background with a strong interest for biophysics. Candidatures, including CV, intention letter and the names and contact information of referees, as well as informal inquiries should be sent to Eric Girard (eric.girard at ibs.fr) and Bruno Franzetti (bruno.franzetti at ibs.fr). Relevant publications from the team: Coquelle et al (2007) Activity, stability and structural studies of lactate dehydrogenases adapted to extreme thermal environments. J Mol Biol 374: 547-562. Dura et al (2009) The structural and biochemical characterizations of a novel TET peptidase complex from Pyrococcus horikoshii reveal an integrated peptide degradation system in hyperthermophilic Archaea. Mol Microbiol 72: 26-40. Girard et al. (2011). Structure-function perturbation and dissociation of tetrameric urate oxidase by high-hydrostatic pressure. Biophys J 98: 2365-2373. -- *************************************************************** Eric Girard Extremophiles and Large Macromolecular Assemblies (ELMA) group Institut de Biologie Structurale J.-P. Ebel UMR 5075 CEA-CNRS-UJF-PSB 41, Rue Jules Horowitz 38027 Grenoble Cedex 1, France Web site:http://www.ibs.fr/ ***************************************************************