Abstract
In the water-oxidizing reactions of photosystem II (PSII), a tyrosine residue plays a key part as an intermediate electron-transfer reactant between the primary donor chlorophylls (the pigment P(680)) and the water-oxidizing Mn cluster. The tyrosine is deprotonated upon oxidation, and the coupling between the proton reaction and electron transfer is of great mechanistic importance for the understanding of the water-oxidation mechanism. Within a programme on artificial photosynthesis, we have made and studied the proton-coupled tyrosine oxidation in a model system and been able to draw mechanistic conclusions that we use to interpret the analogous reactions in PSII.
Full Text
The Full Text of this article is available as a PDF (160.5 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Ahlbrink R., Haumann M., Cherepanov D., Bögershausen O., Mulkidjanian A., Junge W. Function of tyrosine Z in water oxidation by photosystem II: electrostatical promotor instead of hydrogen abstractor. Biochemistry. 1998 Jan 27;37(4):1131–1142. doi: 10.1021/bi9719152. [DOI] [PubMed] [Google Scholar]
- Aubert C., Vos M. H., Mathis P., Eker A. P., Brettel K. Intraprotein radical transfer during photoactivation of DNA photolyase. Nature. 2000 Jun 1;405(6786):586–590. doi: 10.1038/35014644. [DOI] [PubMed] [Google Scholar]
- Diner B. A. Amino acid residues involved in the coordination and assembly of the manganese cluster of photosystem II. Proton-coupled electron transport of the redox-active tyrosines and its relationship to water oxidation. Biochim Biophys Acta. 2001 Jan 5;1503(1-2):147–163. doi: 10.1016/s0005-2728(00)00220-6. [DOI] [PubMed] [Google Scholar]
- Haumann M., Mulkidjanian A., Junge W. Tyrosine-Z in oxygen-evolving photosystem II: a hydrogen-bonded tyrosinate. Biochemistry. 1999 Jan 26;38(4):1258–1267. doi: 10.1021/bi981557i. [DOI] [PubMed] [Google Scholar]
- Hoganson C. W., Babcock G. T. A metalloradical mechanism for the generation of oxygen from water in photosynthesis. Science. 1997 Sep 26;277(5334):1953–1956. doi: 10.1126/science.277.5334.1953. [DOI] [PubMed] [Google Scholar]
- Rappaport F., Lavergne J. Coupling of electron and proton transfer in the photosynthetic water oxidase. Biochim Biophys Acta. 2001 Jan 5;1503(1-2):246–259. doi: 10.1016/s0005-2728(00)00228-0. [DOI] [PubMed] [Google Scholar]
- Renger G. Photosynthetic water oxidation to molecular oxygen: apparatus and mechanism. Biochim Biophys Acta. 2001 Jan 5;1503(1-2):210–228. doi: 10.1016/s0005-2728(00)00227-9. [DOI] [PubMed] [Google Scholar]
- Tommos C., Babcock G. T. Proton and hydrogen currents in photosynthetic water oxidation. Biochim Biophys Acta. 2000 May 12;1458(1):199–219. doi: 10.1016/s0005-2728(00)00069-4. [DOI] [PubMed] [Google Scholar]