Download MendeleyStructural Insights into Substrate Selectivity, Catalytic Mechanism, and Redox Regulation of Rice Photosystem II Core Phosphatase.
Liu, X., Chai, J., Ou, X., Li, M., Liu, Z.(2019) Mol Plant 12: 86-98
- PubMed: 30453087
- DOI: https://doi.org/10.1016/j.molp.2018.11.006
- Primary Citation of Related Structures:
6AE9 - 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 H 2 O 2 . 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.
Organizational Affiliation:
National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, P. R. China; University of Chinese Academy of Sciences, Beijing 100049, P. R. China.
