Design principles of solar light harvesting in plants: Functional architecture of the monomeric antenna CP29

Vincenzo Mascoli, Vladimir Novoderezhkin, Nicoletta Liguori, Pengqi Xu, Roberta Croce*

*Corresponding author for this work

Research output: Contribution to JournalArticleAcademicpeer-review

Abstract

In plants and green algae, light-harvesting complexes (LHCs) are a large family of chlorophyll binding proteins functioning as antennae, collecting solar photons and transferring the absorbed energy to the photosynthetic reaction centers, where light to chemical energy conversion begins. Although LHCs are all highly homologous in their structure and display a variety of common features, each complex finds a specific location and task in the energy transport. One example is CP29, which occupies a pivotal position in Photosystem II, bridging the peripheral antennae to the core. The design principles behind this specificity, however, are still unclear. Here, a synergetic approach combining steady-state and ultrafast spectroscopy, mutational analysis and structure-based exciton modeling allows uncovering the energy landscape of the chlorophylls bound to this complex. We found that, although displaying an overall highly conserved exciton structure very similar to that of other LHCs, CP29 possesses an additional terminal emitter domain. The simultaneous presence of two low energy sites facing the peripheral antennae and the core, allows CP29 to efficiently work as a conduit in the energy flux. Our results show that the LHCs share a common solid architecture but have finely tuned their structure to carry out specific functions.

Original languageEnglish
Article number148156
Pages (from-to)1-13
Number of pages13
JournalBiochimica et Biophysica Acta - Bioenergetics
Volume1861
Issue number3
Early online date24 Jan 2020
DOIs
Publication statusPublished - 1 Mar 2020

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Keywords

  • Chlorophyll
  • Electronic spectroscopy
  • Energy transfer
  • Exciton modeling
  • Light harvesting
  • Mutational analysis

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