8BOR

Photosensory module from DrBphP without PHY tongue

Summary for 8BOR

• Entry DOI: 10.2210/pdb8bor/pdb
• Descriptor: Bacteriophytochrome, 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 (3 entities in total)
• Functional Keywords: kinase, photosensor, transferase, phytochrome
• Biological source: Deinococcus radiodurans R1; More
• Total number of polymer chains: 4
• Total formula weight: 215740.62

Authors

Kurttila, M.,Takala, H.,Ihalainen, J.A. (deposition date: 2022-11-15, release date: 2023-06-28, Last modification date: 2024-11-13)

Primary citation

Kurttila, M.,Rumfeldt, J.,Takala, H.,Ihalainen, J.A.
The interconnecting hairpin extension "arm": An essential allosteric element of phytochrome activity.
Structure, 31:1100-, 2023

PubMed Abstract: In red-light sensing phytochromes, isomerization of the bilin chromophore triggers structural and dynamic changes across multiple domains, ultimately leading to control of the output module (OPM) activity. In between, a hairpin structure, "arm", extends from an interconnecting domain to the chromophore region. Here, by removing this protein segment in a bacteriophytochrome from Deinococcus radiodurans (DrBphP), we show that the arm is crucial for signal transduction. Crystallographic, spectroscopic, and biochemical data indicate that this variant maintains the properties of DrBphP in the resting state. Spectroscopic data also reveal that the armless systems maintain the ability to respond to light. However, there is no subsequent regulation of OPM activity without the arms. Thermal denaturation reveals that the arms stabilize the DrBphP structure. Our results underline the importance of the structurally flexible interconnecting hairpin extensions and describe their central role in the allosteric coupling of phytochromes.

PubMed: 37392739
DOI: 10.1016/j.str.2023.06.007

Experimental method

X-RAY DIFFRACTION (2.3 Å)