Identification of a Na+-Binding Site near the Oxygen-Evolving Complex of Spinach Photosystem II
| Autor: | Alisha Dziarski, Gary W. Brudvig, Victor S. Batista, Hao Li Huang, Marilyn R. Gunner, Divya Kaur, Ipsita Ghosh, Gourab Banerjee, Christopher J. Gisriel, Krystle Reiss, Jimin Wang, Joshua M. Perez-Cruet |
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| Rok vydání: | 2020 |
| Předmět: |
chemistry.chemical_classification
biology Photosystem II Sodium food and beverages chemistry.chemical_element macromolecular substances Oxygen-evolving complex biology.organism_classification Biochemistry Crystallography chemistry.chemical_compound Deprotonation chemistry Spinach Hydroxide Counterion Binding site |
| Zdroj: | Biochemistry. 59:2823-2831 |
| ISSN: | 1520-4995 0006-2960 |
| DOI: | 10.1021/acs.biochem.0c00303 |
| Popis: | The oxygen-evolving complex (OEC) of photosystem II (PSII) is an oxomanganese cluster composed of four redox-active Mn ions and one redox-inactive Ca2+ ion, with two nearby bound Cl- ions. Sodium is a common counterion of both chloride and hydroxide anions, and a sodium-specific binding site has not been identified near the OEC. Here, we find that the oxygen-evolution activity of spinach PSII increases with Na+ concentration, particularly at high pH. A Na+-specific binding site next to the OEC, becomes available after deprotonation of the D1-H337 amino acid residue, is suggested by the analysis of two recently published PSII cryo-electron microscopy maps in combination with quantum mechanical calculations and multiconformation continuum electrostatics simulations. |
| Databáze: | OpenAIRE |
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