6FHT

Crystal structure of an artificial phytochrome regulated adenylate/guanylate cyclase in its dark adapted Pr form

Summary for 6FHT

• Entry DOI: 10.2210/pdb6fht/pdb
• Descriptor: Bacteriophytochrome,Adenylate cyclase, 3-[2-[(Z)-[3-(2-carboxyethyl)-5-[(Z)-(4-ethenyl-3-methyl-5-oxidanylidene-pyrrol-2-ylidene)methyl]-4-methyl-pyrrol-1-ium -2-ylidene]methyl]-5-[(Z)-[(3E)-3-ethylidene-4-methyl-5-oxidanylidene-pyrrolidin-2-ylidene]methyl]-4-methyl-1H-pyrrol-3- yl]propanoic acid, SULFATE ION, ... (5 entities in total)
• Functional Keywords: phytochrome, cyclase, lyase
• Biological source: Deinococcus radiodurans; More
• Total number of polymer chains: 2
• Total formula weight: 162498.01

Authors

Etzl, S.,Winkler, A. (deposition date: 2018-01-15, release date: 2018-04-18, Last modification date: 2024-11-06)

Primary citation

Etzl, S.,Lindner, R.,Nelson, M.D.,Winkler, A.
Structure-guided design and functional characterization of an artificial red light-regulated guanylate/adenylate cyclase for optogenetic applications.
J. Biol. Chem., 293:9078-9089, 2018

PubMed Abstract: Genetically targeting biological systems to control cellular processes with light is the concept of optogenetics. Despite impressive developments in this field, underlying molecular mechanisms of signal transduction of the employed photoreceptor modules are frequently not sufficiently understood to rationally design new optogenetic tools. Here, we investigate the requirements for functional coupling of red light-sensing phytochromes with non-natural enzymatic effectors by creating a series of constructs featuring the bacteriophytochrome linked to a guanylate/adenylate cyclase. Incorporating characteristic structural elements important for cyclase regulation in our designs, we identified several red light-regulated fusions with promising properties. We provide details of one light-activated construct with low dark-state activity and high dynamic range that outperforms previous optogenetic tools and expands our toolkit, as demonstrated by manipulation of locomotor activity. The full-length crystal structure of this phytochrome-linked cyclase revealed molecular details of photoreceptor-effector coupling, highlighting the importance of the regulatory cyclase element. Analysis of conformational dynamics by hydrogen-deuterium exchange in different functional states enriched our understanding of phytochrome signaling and signal integration by effectors. We found that light-induced conformational changes in the phytochrome destabilize the coiled-coil sensor-effector linker, which releases the cyclase regulatory element from an inhibited conformation, increasing cyclase activity of this artificial system. Future designs of optogenetic functionalities may benefit from our work, indicating that rational considerations for the effector improve the rate of success of initial designs to obtain optogenetic tools with superior properties.

PubMed: 29695503
DOI: 10.1074/jbc.RA118.003069

Experimental method

X-RAY DIFFRACTION (2.35 Å)