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Biological crystallogenesis

Crystallography is our favorite investigation tool to characterize the 3D structure of RNAs and proteins. Each crystallographic study consists in four major steps:

The most difficult step in this scenario is very often the crystallization of the molecular target. Getting good crystals of a biomolecule is not an easy task due to the many physical chemical and biological parameters that are involved in the crystallization process. Indeed, we are particularly interested in this research field called biological crystallogenesis, which examines how above mentioned steps influence the quality of a crystal and the accuracy of structural information obtained from its X-ray analysis.

cristaux de thaumatine
Well shaped 3D crystals of protein grown in agarose gel

Over the last twenty five years, our group has been involved in the development of methods that facilitate the preparation of crystals for crystallographic studies like:

  • the use of phase diagrams as optimization tools [Sauter et al 1999a, Zhu et al 2002, Schellenberger et al 2011a]
  • the use of additives to enhance crystal growth and quality [Sauter et al, 1999b, Bonnefond et al. 2011]
  • the crystal growth in agarose gel to reach higher resolution [Sauter et al. 2002, Schellenberger et al 2011a], lower mosaicity [Lorber et al 1999a, 1999b], better cryocooling [Biertümpfel et al. 2005] or ligand soaking [Sauter et al. 2009]
  • the crystallization by the counter-diffusion method [Garcia-Ruìz et al. 2001, Biertümpfel et al. 2002, Dhouib et al 2009]
  • the crystallization in microfluidic chips [Sauter et al 2007, Dhouib et al 2009, Pinker et al 2013, de Wijn et al 2019]
  • the preparation of microcrystals for serial crystallography [de Wijn et al 2020]
ChipX: a microfluidic chip for biomolecule crystallization and in situ serial crystallography analysis