8A7H

Crystal structure of a chimeric LOV-Histidine kinase SB2F1-I66R mutant (light state; asymmetrical variant, trigonal form with long c axis)

Summary for 8A7H

• Entry DOI: 10.2210/pdb8a7h/pdb
• Descriptor: Putative Sensory box protein,Sensor protein FixL, ADENOSINE-5'-TRIPHOSPHATE, Flavin mononucleotide (semi-quinone intermediate) (3 entities in total)
• Functional Keywords: lov domain, pas domain, photocycle, dimerization, signaling blue light photoreceptor, sensory histidine kinase, chimeric, de novo protein, signaling protein
• Biological source: Pseudomonas putida KT2440; More
• Total number of polymer chains: 2
• Total formula weight: 87819.14

Authors

Arinkin, V.,Granzin, J.,Batra-Safferling, R. (deposition date: 2022-06-21, release date: 2024-01-10, Last modification date: 2026-07-15)

Primary citation

Arinkin, V.,Stadler, A.M.,Meier, S.S.M.,Jaeger, K.E.,Moglich, A.,Krauss, U.,Batra-Safferling, R.
Dimer asymmetry in signaling of blue light sensor histidine kinases.
Sci Adv, 12:eaed8943-eaed8943, 2026

PubMed Abstract: Photoreceptor sensory histidine kinases (SHKs) couple light absorption to conformational changes regulating two-component signaling. Despite their importance and widespread use in optogenetics, the underlying structural signaling mechanisms remain poorly understood. Here, we engineered dimeric SHKs based on short light-oxygen-voltage (LOV) proteins, determined their crystal structures, and investigated their signaling mechanisms. Regardless of illumination, the structures adopted a light-state like LOV-LOV dimer with symmetric/straight kinase modules. In contrast, small-angle x-ray scattering together with functional assays revealed pronounced light-dependent rearrangements in solution and allowed the assignment of the kinase-ON dark state to an asymmetric/kinked conformation, whereas the light state adopts a symmetric/straight structure. Comparative analyses of natural and engineered SHKs identified conserved motifs linking light-induced LOV domain rotation to kinase activity. The findings highlight the central role of dimer asymmetry and flexibility in SHK signaling, thereby not least informing the engineering of new light-responsive signaling systems.

PubMed: 42384803
DOI: 10.1126/sciadv.aed8943

Experimental method

X-RAY DIFFRACTION (3.145 Å)