6AE9

X-ray structure of the photosystem II phosphatase PBCP

Summary for 6AE9

• Entry DOI: 10.2210/pdb6ae9/pdb
• Descriptor: Probable protein phosphatase 2C 1, MAGNESIUM ION, PHOSPHATE ION, ... (6 entities in total)
• Functional Keywords: pp2c phosphatase, photosystem ii phosphatase, hydrolase
• Biological source: Oryza sativa subsp. japonica (Rice)
• Total number of polymer chains: 2
• Total formula weight: 58131.32

Authors

Liu, X.Y.,Chai, J.C.,Ou, X.M.,Liu, Z.F. (deposition date: 2018-08-03, release date: 2019-01-02, Last modification date: 2023-11-22)

Primary citation

Liu, X.,Chai, J.,Ou, X.,Li, M.,Liu, Z.
Structural Insights into Substrate Selectivity, Catalytic Mechanism, and Redox Regulation of Rice Photosystem II Core Phosphatase.
Mol Plant, 12:86-98, 2019

PubMed Abstract: Photosystem II (PSII) core phosphatase (PBCP) selectively dephosphorylates PSII core proteins including D1, D2, CP43, and PsbH. PBCP function is required for efficient degradation of the D1 protein in the repair cycle of PSII, a supramolecular machinery highly susceptible to photodamage during oxygenic photosynthesis. Here we present structural and functional studies of PBCP from Oryza sativa (OsPBCP). In a symmetrical homodimer of OsPBCP, each monomer contains a PP2C-type phosphatase core domain, a large motif characteristic of PBCPs, and two small motifs around the active site. The large motif contributes to the formation of a substrate-binding surface groove, and is crucial for the selectivity of PBCP toward PSII core proteins and against the light-harvesting proteins. Remarkably, the phosphatase activity of OsPBCP is strongly inhibited by glutathione and HO. S-Glutathionylation of cysteine residues may introduce steric hindrance and allosteric effects to the active site. Collectively, these results provide detailed mechanistic insights into the substrate selectivity, redox regulation, and catalytic mechanism of PBCP.

PubMed: 30453087
DOI: 10.1016/j.molp.2018.11.006

Experimental method

X-RAY DIFFRACTION (1.47 Å)