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Chlorophyll-Binding Proteins

  1. Heiko Lokstein2,
  2. Bernhard Grimm1

Published Online: 15 MAY 2013

DOI: 10.1002/9780470015902.a0020085.pub2

eLS

eLS

How to Cite

Lokstein, H. and Grimm, B. 2013. Chlorophyll-Binding Proteins. eLS. .

Author Information

  1. 1

    Humboldt-Universität zu Berlin, Berlin, Germany

  2. 2

    University of Glasgow, Glasgow, UK

Publication History

  1. Published Online: 15 MAY 2013

Abstract

Chlorophylls and bacteriochlorophylls are the dominant pigments on Earth and serve – noncovalently bound to specific proteins – as principal light-harvesting as well as energy-transforming cofactors in photosynthetic organisms. The major groups of (bacterio)chlorophyll-binding proteins are the photosynthetic reaction centres (RCs) and the associated light-harvesting (antenna) complexes. Other proteins include water-soluble chlorophyll-binding proteins as well the chlorophyll biosynthetic and degrading enzymes. Although all RCs show structural homologies and appear to have evolved from a common ancestor, light-harvesting antenna designs vary considerably. The enormous progress that has been achieved in the elucidation of structures and functions of chlorophyll-binding proteins is reviewed. It has become increasingly clear that light-harvesting complexes do not only serve to enlarge the absorption cross-sections of the RCs but are important in the adaptation of the photosynthetic apparatus and regulation of the energy-transforming processes in response to environmental and endogenous conditions.

Key Concepts:

  • Chlorophylls and bacteriochlorophylls serve – noncovalently bound to specific proteins – as principal energy-transforming cofactors in photosynthesis.

  • Light-harvesting antenna complexes ensure optimised light harvesting and transfer of excitation energy to the reaction centres of the photosystems.

  • Reaction centre proteins remained fairly conserved during evolution, whereas photosynthetic organisms developed many distinct forms of light-harvesting complexes.

  • Oxygenic photosynthesis evolved to two different photosystems that have most likely emerged from a common ancestor.

  • The antenna system of plants and algae can ‘switch’ from effective light harvesting to photoprotective excess excitation dissipation to prevent photo-oxidative damage.

Keywords:

  • bacteriochlorophylls;
  • chlorophylls;
  • light-harvesting complexes;
  • photosynthesis;
  • pigment–protein complexes;
  • reaction centres;
  • electron transport;
  • photosystems;
  • photoprotection;
  • nonphotochemical quenching