Structural and functional diversification of the light-harvesting complexes in photosynthetic eukaryotes.
Eukaryotes acquired photosynthetic metabolism over a billion years ago, and during that time the light-harvesting antennae have undergone significant structural and functional divergence. The antenna systems are generally used to harvest and transfer excitation energy into the reaction centers to drive photosynthesis, but also have the dual role of energy dissipation. Phycobilisomes formed the first antenna system in oxygenic photoautotrophs, and this soluble protein complex continues to be the dominant antenna in extant cyanobacteria, glaucophytes, and red algae. However, phycobilisomes were lost multiple times during eukaryotic evolution in favor of a thylakoid membrane-integral light-harvesting complex (LHC) antenna system found in the majority of eukaryotic taxa. While photosynthesis spread across different eukaryotic kingdoms via endosymbiosis, the antenna systems underwent extensive modification as photosynthetic groups optimized their light-harvesting capacity and ability to acclimate to changing environmental conditions. This review discusses the different classes of LHCs within photosynthetic eukaryotes and examines LHC diversification in different groups in a structural and functional context.
Neilson
Jonathan A D
JA
Department of Biology, University of New Brunswick, Fredericton, NB E3B 5A3, Canada.
Durnford
Dion G
DG
D002734:Chlorophyll / Q000378:metabolism; D056890:Eukaryota / Q000378:metabolism*; D019143:Evolution, Molecular; D045342:Light-Harvesting Protein Complexes / Q000235:genetics / Q000378:metabolism*; D010788:Photosynthesis; D010802:Phylogeny
D045342:Light-Harvesting Protein Complexes; D002734:Chlorophyll