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Updated: Jun 15, 2026

Isolation and Characterization of Intact Phycobilisome in Cyanobacteria
Published on: November 10, 2021
Crystal structure of PsbQ from Synechocystis sp. PCC 6803 at 1.8 A: implications for binding and function in
Simon A Jackson1, Robert D Fagerlund, Sigurd M Wilbanks
1Department of Biochemistry, University of Otago, Dunedin 9054, New Zealand.
Abstract:
In Synechocystis sp. PCC 6803, PsbQ is associated with photosystem II (PSII) complexes with the highest activity and stability. However, this subunit is not found in PSII X-ray crystallographic structures from Thermosynechococcus elongatus or Thermosynechococcus vulcanus. We present the crystal structure of cyanobacterial PsbQ determined in the presence and absence of Zn(2+). The protein has a well-defined helical core, containing four helices arranged in an up-down-up-down fold. A conserved potential interaction site composed of a divalent metal binding site and adjacent hydrophobic pocket has been identified.
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