Giessen Plant Physiology phytochrome work selected as lead project for European Neutron Crystallography facility
Jon Hughes's group at the JLU's Institute for Plant Physiology works on phytochromes, photoreceptor molecules used by all plants and many microorganisms to perceive and respond to their light environment. A particular focus is to elucidate the 3D molecular structure to understand the mechanism by which the protein absorbs light and then transmits the signal to the cell. The movement of protons and re-arrangement of hydrogen bonds is important in phytochrome action, as in many proteins - the collaborative research program of SFB 1078 based in Berlin is devoted to this and includes the Hughes group. Like most others worldwide, Hughes uses X-ray crystallography to derive 3D protein structures in order to find out how they work – but unfortunately, protons are invisible to X-rays! One solution to this problem is Hughes's collaboration with the Matysik group in Leipzig to exploit solid-state nuclear magnetic resonance (NMR) methods which are particularly good at detecting protons. Alternatively, though, it is possible to use neutrons rather than X-rays to probe the crystals, as neutron diffraction allows protons to be localized. But there's another problem: whereas incredibly powerful X-ray sources exist, it is much, much more difficult to generate powerful beams of neutrons. A new European research facility in Lund (Sweden) should change that, however, providing a very large technological step forward from the current premier neutron source at the Oak Ridge National Laboratory in the USA. Because of the great interest in phytochrome function, the Hughes group has been selected as a "guinea pig" for the first experiments using the Lund Spallation Source. This work might allow protonation dynamics in the phytochrome molecule to be studied directly, not only helping us to understand how phytochromes work but also how protein structure/function in general is regulated by protonation dynamics.
See http://www.uni-giessen.de/fbz/fb08/Inst/pflphysfor more details about Plant Physiology at the JLU.