The 2.2 Å Crystal Structure of a Pocilloporin Pigment Reveals a Nonplanar Chromophore Conformation Academic Article uri icon


  • Reef-building corals contain host pigments, termed pocilloporins, that function to regulate the light environment of their resident microalgae by acting as a photoprotectant in excessive sunlight. We have determined the crystal structure of an intensely blue, nonfluorescent pocilloporin to 2.2 A resolution and a genetically engineered fluorescent variant to 2.4 A resolution. The pocilloporin chromophore structure adopts a markedly different conformation in comparison with the DsRed chromophore, despite the chromophore sequences (Gln-Tyr-Gly) being identical; the tyrosine ring of the pocilloporin chromophore is noncoplanar and in the trans configuration. Furthermore, the fluorescent variant adopted a noncoplanar chromophore conformation. The data presented here demonstrates that the conformation of the chromophore is highly dependent on its immediate environment.


  • Prescott, Mark
  • Ling, Michael
  • Beddoe, Travis
  • Oakley, Aaron J
  • Dove, Sophie
  • Hoegh-Guldberg, Ove
  • Devenish, Rodney J
  • Rossjohn, Jamie

publication date

  • March 2003