Signal transduction in LOV and BLUF blue light photoreceptors.

• Applicant: Professorin Dr. Ilme Schlichting
• Subject Area: Biophysics
• Term: from 2010 to 2016
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 119438981

This project aims at obtaining new structural information on light-activated enzymes containing flavin- and retinal-based photoreceptor domains. The major goal is to understand the coupling between the sensing photoreceptor domains and the regulated output entities, a prerequisite for any rational (re)design of function to increase potential applications. We will focus on the expression of several natural light-activated cyclases (PAC) of Astasia and Beggiatoa, light-activated kinases (phototropins) of Mougeotia, and light-regulated transcription factors (Aureochromes) of Heterokontophytes. In addition, we will work on custom-designed synthetic systems where the structural changes induced in the photosensor domain unmask interaction regions with regulatory proteins of the attached output domain. We will engineer rhodopsin-cyclase chimera by merging well-studied bacterial cyclases with the light-sensitive phoborhodopsin (SRII) via a versatile HAMP domain linker. All proteins that are functional and light-activatable will be subjected to crystallization screens for structure determination. Structurally characterized proteins will be studied in detail enzymatically, spectroscopically and functionally in vitro and in vivo.

• DFG Programme: Research Units
• Subproject of: FOR 1279: “Protein-based Photoswitches” as Optogenetic Tools