4gcz
From Proteopedia
Structure of a blue-light photoreceptor
Structural highlights
FunctionPHOT_BACSU Exhibits the same spectroscopical features and blue-light induced photochemistry as plants phototropins, with the reversible formation of a blue-shifted photoproduct, assigned to an FMN-cysteine thiol adduct. Although it is a positive regulator in the activation of the environmental signaling branch of the general stress transcription factor sigma-B, its precise role is undetermined.[1] FIXL_BRADU Publication Abstract from PubMedTwo-component systems (TCSs), which comprise sensor histidine kinases (SHK) and response-regulator proteins, represent the predominant strategy by which prokaryotes sense and respond to a changing environment. Despite paramount biological importance, a dearth exists of intact SHK structures containing both sensor and effector modules. Here, we report the full-length crystal structure of the engineered, dimeric, blue-light-regulated SHK YF1 at 2.3 A resolution, in which two N-terminal light-oxygen-voltage (LOV) photosensors are connected by a coiled coil to the C-terminal effector modules. A second coaxial coiled coil derived from the N-termini of the LOV photosensors and inserted between them crucially modulates light regulation: single mutations within this coiled coil attenuate or even invert the signal response of the TCS. Structural motifs identified in YF1 recur in signal receptors, and the underlying signaling principles and mechanisms may be widely shared between soluble and transmembrane, prokaryotic, and eukaryotic signal receptors of diverse biological activity. Full-length structure of a sensor histidine kinase pinpoints coaxial coiled coils as signal transducers and modulators.,Diensthuber RP, Bommer M, Gleichmann T, Moglich A Structure. 2013 Jul 2;21(7):1127-36. doi: 10.1016/j.str.2013.04.024. Epub 2013, Jun 6. PMID:23746806[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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