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

*Corresponding author for this work

Research output: Contribution to JournalArticleAcademicpeer-review

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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.

Original languageEnglish
Pages (from-to)137-144
Number of pages8
JournalBiochimica et Biophysica Acta - Bioenergetics
Issue number2
Early online date21 Nov 2017
Publication statusPublished - Feb 2018


This work was supported by the French Infrastructure for Integrated Structural Biology (FRISBI) ANR-10-INSB-05 (A.G, C.I., B.R); the European Research Council (ERC) through an Advanced Investigator Grant, contract no. 267333 (R.v.G., B.R.); the French Agence Nationale de la Recherché (ANR) through a Chaire d'excellence, ANR-07-CEX-009-01 (A.G., O.I.); the European Union (EU) FP6 MEST-CT-2004-008048 Marie Curie Early Stage Training Network via the Advanced Training in Laser Sciences project (T.P.J.K.); the EU Access to Research Infrastructures action of the Improving Human Potential Program , contract no. RII-CT-2003-506350 (A.G.); CEA-Eurotalents program, European Union contract no. PCOFUND-GA-2008-228664 (C.I.); TOP grant ( 700.58.305 ) from the Foundation of Chemical Sciences, part of the Netherlands Organization for Scientific Research (C.I. and R.v.G.). Appendix A

FundersFunder number
Foundation of Chemical Sciences
Netherlands Organization for Scientific Research
Technology Opportunities Program
European CommissionPCOFUND-GA-2008-228664, 700.58.305, FP6 MEST-CT-2004-008048
European Research Council267333
Agence Nationale de la Recherche
French Infrastructure for Integrated Structural BiologyANR-10-INSB-05


    • Light harvesting complexes
    • Photosynthesis
    • Purple bacteria
    • Single molecule spectroscopy


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