8F71

Crystal structure of the histidine kinase domain of bacteriophytochrome RpBphP2

Summary for 8F71

• Entry DOI: 10.2210/pdb8f71/pdb
• Descriptor: Histidine kinase, ADENOSINE-5'-TRIPHOSPHATE, MAGNESIUM ION, ... (4 entities in total)
• Functional Keywords: histidine kinase, bacteriophytochrome, signaling protein, transferase
• Biological source: Rhodopseudomonas palustris CGA009
• Total number of polymer chains: 2
• Total formula weight: 60184.71

Authors

Yang, X.,Kumarapperuma, I.,Tom, I. (deposition date: 2022-11-17, release date: 2023-11-22, Last modification date: 2024-10-23)

Primary citation

Kumarapperuma, I.,Tom, I.P.,Bandara, S.,Montano, S.,Yang, X.
Mode of autophosphorylation in bacteriophytochromes RpBphP2 and RpBphP3.
Photochem Photobiol Sci, 22:1257-1266, 2023

PubMed Abstract: Phytochromes are red-light photoreceptors that regulate a wide range of physiological processes in plants, fungi and bacteria. Canonical bacteriophytochromes are photosensory histidine kinases that undergo light-dependent autophosphorylation, thereby regulating cellular responses to red light via two-component signaling pathways. However, the molecular mechanism of kinase activation remains elusive for bacteriophytochromes. In particular, the directionality of autophosphorylation is still an open question in these dimeric photoreceptor kinases. In this work, we perform histidine kinase assays on two tandem bacteriophytochromes RpBphP2 and RpBphP3 from the photosynthetic bacterium Rhodopseudomonas palustris. By examining the kinase activities of full-length bacteriophytochromes and two loss-of-function mutants under different light conditions, we demonstrate that RpBphP2 and RpBphP3 undergo light-dependent trans-phosphorylation between protomers in both homodimeric and heterodimeric forms. We have further determined the crystal structure of the histidine kinase domains of RpBphP2 at 3.19 Å resolution. Based on structural comparisons and homology modeling, we also present a model to account for the actions of trans-autophosphorylation in bacteriophytochromes.

PubMed: 36757561
DOI: 10.1007/s43630-023-00366-9

Experimental method

X-RAY DIFFRACTION (3.19 Å)