Cross-linking Evidence for Multiple Interactions of the PsbP and PsbQ Proteins in a Higher Plant Photosystem II Supercomplex
| Autor: | Yoichiro Fukao, Fumihiko Sato, Taishi Nishimura, Jon Nield, Kentaro Ifuku, Kunio Ido |
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| Rok vydání: | 2014 |
| Předmět: |
Models
Molecular Cyanobacteria Photosystem II Protein subunit Molecular Sequence Data Plant Biology macromolecular substances Oxygen-evolving complex Biochemistry Spinacia oleracea Tandem Mass Spectrometry polycyclic compounds Protein Interaction Domains and Motifs Amino Acid Sequence Protein Structure Quaternary Molecular Biology Peptide sequence biology Photosystem II Protein Complex food and beverages Cell Biology biology.organism_classification Recombinant Proteins Chloroplast Protein Subunits Cross-Linking Reagents Amino Acid Substitution Mutagenesis Site-Directed Biophysics Spinach Function (biology) |
| Zdroj: | Journal of Biological Chemistry. 289:20150-20157 |
| ISSN: | 0021-9258 |
| DOI: | 10.1074/jbc.m114.574822 |
| Popis: | The extrinsic subunits of membrane-bound photosystem II (PSII) maintain an essential role in optimizing the water-splitting reaction of the oxygen-evolving complex (OEC), even though they have undergone drastic change during the evolution of oxyphototrophs from symbiotic cyanobacteria to chloroplasts. Two specific extrinsic proteins, PsbP and PsbQ, bind to the lumenal surface of PSII in green plants and maintain OEC conformation and stabilize overall enzymatic function; however, their precise location has not been fully resolved. In this study, PSII-enriched membranes, isolated from spinach, were subjected to chemical cross-linking combined with release-reconstitution experiments. We observed direct interactions between PsbP and PsbE, as well as with PsbR. Intriguingly, PsbP and PsbQ were further linked to the CP26 and CP43 light-harvesting proteins. In addition, two cross-linked sites, between PsbP and PsbR, and that of PsbP and CP26, were identified by tandem mass spectrometry. These data were used to estimate the binding topology and location of PsbP, and the putative positioning of PsbQ and PsbR on the lumenal surface of the PSII. Our model gives new insights into the organization of PSII extrinsic subunits in higher plants and their function in stabilizing the OEC of the PSII supercomplex. |
| Databáze: | OpenAIRE |
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