Apoprotein heterogeneity increases spectral disorder and a step-wise modification of the B850 fluorescence peak position

Cristian Ilioaia; Tjaart P J Krüger; Oana Ilioaia; Bruno Robert; Rienk van Grondelle; Andrew Gall

doi:10.1016/j.bbabio.2017.11.003

Apoprotein heterogeneity increases spectral disorder and a step-wise modification of the B850 fluorescence peak position

Biochim Biophys Acta Bioenerg. 2018 Feb;1859(2):137-144. doi: 10.1016/j.bbabio.2017.11.003. Epub 2017 Nov 21.

Authors

Cristian Ilioaia¹, Tjaart P J Krüger², Oana Ilioaia³, Bruno Robert⁴, Rienk van Grondelle⁵, Andrew Gall⁶

Affiliations

¹ Institut des sciences du vivant Frédéric Joliot, Commissariat à l'Energie Atomique et aux énergies alternatives (CEA), 91191 Gif-sur-Yvette, France; Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91191 Gif-sur-Yvette cedex, France; Department of Physics and Astronomy, Faculty of Sciences, VU University Amsterdam, De Boelelaan, 1081 HV Amsterdam, The Netherlands. Electronic address: cristian.ilioaia@cea.fr.
² Department of Physics and Astronomy, Faculty of Sciences, VU University Amsterdam, De Boelelaan, 1081 HV Amsterdam, The Netherlands; Department of Physics, University of Pretoria, Hatfield, 0028 Pretoria, South Africa.
³ Institut des sciences du vivant Frédéric Joliot, Commissariat à l'Energie Atomique et aux énergies alternatives (CEA), 91191 Gif-sur-Yvette, France; Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91191 Gif-sur-Yvette cedex, France.
⁴ Institut des sciences du vivant Frédéric Joliot, Commissariat à l'Energie Atomique et aux énergies alternatives (CEA), 91191 Gif-sur-Yvette, France; Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91191 Gif-sur-Yvette cedex, France; Department of Physics and Astronomy, Faculty of Sciences, VU University Amsterdam, De Boelelaan, 1081 HV Amsterdam, The Netherlands.
⁵ Department of Physics and Astronomy, Faculty of Sciences, VU University Amsterdam, De Boelelaan, 1081 HV Amsterdam, The Netherlands. Electronic address: r.van.grondelle@vu.nl.
⁶ Institut des sciences du vivant Frédéric Joliot, Commissariat à l'Energie Atomique et aux énergies alternatives (CEA), 91191 Gif-sur-Yvette, France; Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91191 Gif-sur-Yvette cedex, France. Electronic address: andrrew.gall@cea.fr.

PMID: 29174011
DOI: 10.1016/j.bbabio.2017.11.003

Abstract

It has already been established that the quaternary structure of the main light-harvesting complex (LH2) from the photosynthetic bacterium Rhodopseudomonas palustris is a nonameric 'ring' of PucAB heterodimers and under low-light culturing conditions an increased diversity of PucB synthesis occurs. In this work, single molecule fluorescence emission studies show that different classes of LH2 'rings' are present in "low-light" adapted cells and that an unknown chaperon process creates multiple sub-types of 'rings' with more conformational sub-states and configurations. This increase in spectral disorder significantly augments the cross-section for photon absorption and subsequent energy flow to the reaction centre trap when photon availability is a limiting factor. This work highlights yet another variant used by phototrophs to gather energy for cellular development.

Keywords: Light harvesting complexes; Photosynthesis; Purple bacteria; Single molecule spectroscopy.

Publication types

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

MeSH terms

Apoproteins / chemistry*
Bacterial Proteins / chemistry*
Light-Harvesting Protein Complexes / chemistry*
Rhodopseudomonas / chemistry*
Spectrometry, Fluorescence

Substances

Apoproteins
Bacterial Proteins
Light-Harvesting Protein Complexes

Grants and funding

267333/ERC_/European Research Council/International