10.1021/bi100217h.s002 Simon A. Jackson Simon A. Jackson Robert D. Fagerlund Robert D. Fagerlund Sigurd M. Wilbanks Sigurd M. Wilbanks Julian J. Eaton-Rye Julian J. Eaton-Rye Crystal Structure of PsbQ from <i>Synechocystis</i> sp. PCC 6803 at 1.8 Å: Implications for Binding and Function in Cyanobacterial Photosystem II American Chemical Society 2010 Thermosynechococcus elongatus crystal structure cyanobacterial PsbQ helical core Synechocystis sp Cyanobacterial Photosystem IIIn Synechocystis sp PCC 6803 Thermosynechococcus vulcanus photosystem II crystal Structure divalent metal binding site PSII interaction site 2010-04-06 00:00:00 Journal contribution https://acs.figshare.com/articles/journal_contribution/Crystal_Structure_of_PsbQ_from_i_Synechocystis_i_sp_PCC_6803_at_1_8_Implications_for_Binding_and_Function_in_Cyanobacterial_Photosystem_II/2779273 In <i>Synechocystis</i> 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 <i>Thermosynechococcus elongatus</i> or <i>Thermosynechococcus vulcanus</i>. We present the crystal structure of cyanobacterial PsbQ determined in the presence and absence of Zn<sup>2+</sup>. 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.