The mechanism of cyclic electron flow

Biochim Biophys Acta Bioenerg. 2019 May 1;1860(5):433-438. doi: 10.1016/j.bbabio.2018.12.005. Epub 2019 Mar 7.

Abstract

Apart from the canonical light-driven linear electron flow (LEF) from water to CO2, numerous regulatory and alternative electron transfer pathways exist in chloroplasts. One of them is the cyclic electron flow around Photosystem I (CEF), contributing to photoprotection of both Photosystem I and II (PSI, PSII) and supplying extra ATP to fix atmospheric carbon. Nonetheless, CEF remains an enigma in the field of functional photosynthesis as we lack understanding of its pathway. Here, we address the discrepancies between functional and genetic/biochemical data in the literature and formulate novel hypotheses about the pathway and regulation of CEF based on recent structural and kinetic information.

Keywords: Biophysics; Cyclic electron flow; Cytochrome b(6)f; Photosynthesis; Photosystem I; Plastoquinone.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Adenosine Triphosphate / metabolism*
  • Chloroplasts / enzymology*
  • Electron Transport / physiology
  • Kinetics
  • Photosynthesis / physiology*
  • Photosystem I Protein Complex / metabolism*
  • Photosystem II Protein Complex / metabolism*

Substances

  • Photosystem I Protein Complex
  • Photosystem II Protein Complex
  • Adenosine Triphosphate