The N-terminal sequence of the extrinsic PsbP protein modulates the redox potential of Cyt b559 in photosystem II
| Autor: | Ryo Nagao, Taishi Nishimura, Kentaro Ifuku, Takumi Noguchi, Fumihiko Sato, Jon Nield |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
0106 biological sciences
0301 basic medicine Conformational change Photosystem II Cytochrome Protein subunit Protein domain macromolecular substances Biology 01 natural sciences Redox Article 03 medical and health sciences Electron transfer Protein Domains Spinacia oleracea Botany Multidisciplinary Photosystem II Protein Complex food and beverages Cytochrome b Group 030104 developmental biology Membrane Biophysics biology.protein Oxidation-Reduction 010606 plant biology & botany |
| Zdroj: | Scientific Reports |
| ISSN: | 2045-2322 |
| Popis: | The PsbP protein, an extrinsic subunit of photosystem II (PSII) in green plants, is known to induce a conformational change around the catalytic Mn4CaO5 cluster securing the binding of Ca2+ and Cl– in PSII. PsbP has multiple interactions with the membrane subunits of PSII, but how these affect the structure and function of PSII requires clarification. Here, we focus on the interactions between the N-terminal residues of PsbP and the α subunit of Cytochrome (Cyt) b559 (PsbE). A key observation was that a peptide fragment formed of the first N-terminal 15 residues of PsbP, ‘pN15’, was able to convert Cyt b559 into its HP form. Interestingly, addition of pN15 to NaCl-washed PSII membranes decreased PSII’s oxygen-evolving activity, even in the presence of saturating Ca2+ and Cl– ions. In fact, pN15 reversibly inhibited the S1 to S2 transition of the OEC in PSII. These data suggest that pN15 can modulate the redox property of Cyt b559 involved in the side-electron pathway in PSII. This potential change of Cyt b559, in the absence of the C-terminal domain of PsbP, however, would interfere with any electron donation from the Mn4CaO5 cluster, leading to the possibility that multiple interactions of PsbP, binding to PSII, have distinct roles in regulating electron transfer within PSII. |
| Databáze: | OpenAIRE |
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