Recommended Citation
Ibrahim, Iskander M.; Wu, Huan; Ezhov, Roman; Kayanja, Gilbert E.; Zakharov, Stanislav D.; Du, Yanyan; Tao, Weiguo Andy; Pushkar, Yulia; Cramer, William A.; and Puthiyaveetil, Sujith, "An evolutionarily conserved iron-sulfur cluster underlies redox sensory function of the Chloroplast Sensor Kinase" (2020). Purdue University Libraries Open Access Publishing Fund. Paper 134.
http://dx.doi.org/10.1038/s42003-019-0728-4
DOI
10.1038/s42003-019-0728-4
Date of this Version
1-8-2020
Abstract
Photosynthetic efficiency depends on equal light energy conversion by two spectrally distinct, serially-connected photosystems. The redox state of the plastoquinone pool, located between the two photosystems, is a key regulatory signal that initiates acclimatory changes in the relative abundance of photosystems. The Chloroplast Sensor Kinase (CSK) links the plastoquinone redox signal with photosystem gene expression but the mechanism by which it monitors the plastoquinone redox state is unclear. Here we show that the purified Arabidopsis and Phaeodactylum CSK and the cyanobacterial CSK homologue, Histidine kinase 2 (Hik2), are iron-sulfur proteins. The Fe-S cluster of CSK is further revealed to be a high potential redox-responsive [3Fe-4S] center. CSK responds to redox agents with reduced plastoquinone suppressing its autokinase activity. Redox changes within the CSK iron-sulfur cluster translate into conformational changes in the protein fold. These results provide key insights into redox signal perception and propagation by the CSK-based chloroplast two-component system.
Comments
This is the publisher PDF of Ibrahim, I.M., Wu, H., Ezhov, R. et al. An evolutionarily conserved iron-sulfur cluster underlies redox sensory function of the Chloroplast Sensor Kinase. Communications Biology 3, 13 (2020). This article is distributed under a CC-BY license, and is available at DOI: 10.1038/s42003-019-0728-4.