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Figure 4
Schematic representation of the crystallization experiment of cgAUS1. (I) cgAUS1 after setting up the crystallization experiment; the protein exists as a monomer in solution. (II) Crystallization set-up after a few hours; partial precipitation occurs due to unspecific interactions between cgAUS1 monomers. (IIIA) Crystallization set-up after a longer period of time, the precipitate dissolves again under the formation of a high dense protein phase (LLPS) containing clusters of protein molecules (here the tetrameric arrangement of cgAUS1 is shown within the LLPS built of the crystallographic dimer). (IIIB) The same scenario as in (IIIA), but cocrystallized with TEW. As all crystal forms obtained are composed of the same crystallographic dimer, it is very likely that these dimers are crucial for the formation of the LLPS and thus the crystallization process. Nucleation and crystal growth was difficult to control within the LLPS zone in the absence of TEW (IIIA), which resulted in crystal forms of lower quality. However, in the presence of TEW (IIIB), both nucleation and crystal growth were dramatically improved, leading to a new crystal form of higher quality. cgAUS1 molecules are depicted as green cartoons, TEW is represented as a cluster of red spheres, and the LLPS is marked by a red circle.

Volume 4| Part 6| November 2017| Pages 734-740
ISSN: 2052-2525