<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<meta http-equiv="content-type" content="text/html;
charset=ISO-8859-1">
</head>
<body bgcolor="#ffffff" text="#000000">
<b>Living deep: Structural basis of piezophilic adaptation</b><br>
ELMA group. Institut de Biologie Structurale J.-P. Ebel – Grenoble –
France<br>
<a class="moz-txt-link-freetext"
href="http://www.ibs.fr/groupes/groupe-extremophiles-et-grands/">http://www.ibs.fr/groupes/groupe-extremophiles-et-grands/</a><br>
<br>
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)<br>
<br>
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.<br>
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).<br>
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<br>
LDH/MalDH from Thermococcus and Pyrococcus phylums (including
Pyrococcus yayanossi CH1) isolated at various water depths.<br>
<br>
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.<br>
<br>
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.<br>
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).<br>
<br>
Relevant publications from the team:<br>
Coquelle et al (2007) Activity, stability and structural studies of
lactate dehydrogenases adapted to extreme thermal environments. J
Mol Biol 374: 547-562.<br>
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.<br>
Girard et al. (2011). Structure-function perturbation and
dissociation of tetrameric urate oxidase by high-hydrostatic
pressure. Biophys J 98: 2365-2373.<br>
<pre class="moz-signature" cols="72">--
***************************************************************
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: <a class="moz-txt-link-freetext" href="http://www.ibs.fr/">http://www.ibs.fr/</a>
***************************************************************
</pre>
</body>
</html>