Extended Data Fig. 3: Isomorphous difference maps in the second monomer at the QB site.
From: Structures of the intermediates of Kok’s photosynthetic water oxidation clock
a–c, Fobs − Fobs maps contoured at 3σ at plastoquinone QB in monomer a. a, 1F − 0F difference map matching reduction of the plastoquinone to a semiquinone and concomitant slight geometry change. b, 2F − 0F difference map matching replacement of the fully reduced quinol with another quinone at the original position. c, 3F − 0F difference map, showing again structural changes similar to the 1F − 0F map, indicating formation of the semiquinone. Similar views are shown for monomer A in Fig. 1d–f and comparison of both monomers indicates similar flash-induced changes in both monomers.
