Abstract
AbstractPhotosynthetic 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.
Publisher
Springer Science and Business Media LLC
Subject
General Agricultural and Biological Sciences,General Biochemistry, Genetics and Molecular Biology,Medicine (miscellaneous)
Reference47 articles.
1. Johnson, D. C., Dean, D. R., Smith, A. D. & Johnson, M. K. Structure, function, and formation of biological iron-sulfur clusters. Annu. Rev. Biochem. 74, 247–281 (2005).
2. Glaser, T., Hedman, B., Hodgson, K. O. & Solomon, E. I. Ligand K-edge X-ray absorption spectroscopy: a direct probe of ligand-metal covalency. J. Am. Chem. Soc. 33, 859–868 (2000).
3. Mouesca, J. M., Noodleman, L., Case, D. A. & Lamotte, B. Spin-densities and spin coupling in iron-sulfur clusters - a new analysis of hyperfine coupling-constants. Inorg. Chem. 34, 4347–4359 (1995).
4. Green, J., Bennett, B., Jordan, P., Ralph, E. T., Thomson, A. J. & Guest, J. R. Reconstitution of the [4Fe-4S] cluster in FNR and demonstration of the aerobic-anaerobic transcription switch in vitro. Biochem. J. 316, 887–892 (1996).
5. Demple, B., Ding, H. E. & Jorgensen, M. Escherichia coli SoxR protein: sensor/transducer of oxidative stress and nitric oxide. Methods Enzymol. 348, 355–364 (2002).
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