Dimerization of core complexes as an efficient strategy for energy trapping in Rhodobacter sphaeroides
(2016) In Biochimica et Biophysica Acta - Bioenergetics 1857(6). p.634-642- Abstract
In the purple phototrophic bacterium Rhodobacter sphaeroides, light harvesting LH2 complexes transfer absorbed solar energy to RC-LH1-PufX core complexes, which are mainly found in the dimeric state. Many other purple phototrophs have monomeric core complexes and the basis for requiring dimeric cores is not fully established, so we analysed strains of Rba. sphaeroides that contain either native dimeric core complexes or altered monomeric cores harbouring a deletion of the first 12 residues from the N-terminus of PufX, which retains the PufX polypeptide but removes the major determinant of core complex dimerization. Membranes were purified from strains with dimeric or monomeric cores, and with either high or low levels of the LH2... (More)
In the purple phototrophic bacterium Rhodobacter sphaeroides, light harvesting LH2 complexes transfer absorbed solar energy to RC-LH1-PufX core complexes, which are mainly found in the dimeric state. Many other purple phototrophs have monomeric core complexes and the basis for requiring dimeric cores is not fully established, so we analysed strains of Rba. sphaeroides that contain either native dimeric core complexes or altered monomeric cores harbouring a deletion of the first 12 residues from the N-terminus of PufX, which retains the PufX polypeptide but removes the major determinant of core complex dimerization. Membranes were purified from strains with dimeric or monomeric cores, and with either high or low levels of the LH2 complex. Samples were interrogated with absorption, steady-state fluorescence, and picosecond time-resolved fluorescence kinetic spectroscopies to reveal their light-harvesting and energy trapping properties. We find that under saturating excitation light intensity the photosynthetic membranes containing LH2 and monomeric core complexes have fluorescence lifetimes nearly twice that of membranes with LH2 plus dimeric core complexes. This trend of increased lifetime is maintained with RCs in the open state as well, and for two different levels of LH2 content. Thus, energy trapping is more efficient when photosynthetic membranes of Rba. sphaeroides consist of RC-LH1-PufX dimers and LH2 complexes.
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- author
- Chenchiliyan, Manoop LU ; Timpmann, Kõu ; Jalviste, Erko ; Adams, Peter G. ; Hunter, C. Neil and Freiberg, Arvi
- publishing date
- 2016-06
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- LH1, LH2, Light harvesting, Photosynthesis, Photosynthetic excitons, RC
- in
- Biochimica et Biophysica Acta - Bioenergetics
- volume
- 1857
- issue
- 6
- pages
- 9 pages
- publisher
- Elsevier
- external identifiers
-
- pmid:27013332
- scopus:84964470910
- ISSN
- 0005-2728
- DOI
- 10.1016/j.bbabio.2016.03.020
- language
- English
- LU publication?
- no
- additional info
- Publisher Copyright: © 2016 Elsevier B.V. All rights reserved.
- id
- 3987edc6-d134-490a-82d5-eb10920d6ff6
- date added to LUP
- 2023-06-16 10:42:15
- date last changed
- 2024-04-19 22:54:17
@article{3987edc6-d134-490a-82d5-eb10920d6ff6,
abstract = {{<p>In the purple phototrophic bacterium Rhodobacter sphaeroides, light harvesting LH2 complexes transfer absorbed solar energy to RC-LH1-PufX core complexes, which are mainly found in the dimeric state. Many other purple phototrophs have monomeric core complexes and the basis for requiring dimeric cores is not fully established, so we analysed strains of Rba. sphaeroides that contain either native dimeric core complexes or altered monomeric cores harbouring a deletion of the first 12 residues from the N-terminus of PufX, which retains the PufX polypeptide but removes the major determinant of core complex dimerization. Membranes were purified from strains with dimeric or monomeric cores, and with either high or low levels of the LH2 complex. Samples were interrogated with absorption, steady-state fluorescence, and picosecond time-resolved fluorescence kinetic spectroscopies to reveal their light-harvesting and energy trapping properties. We find that under saturating excitation light intensity the photosynthetic membranes containing LH2 and monomeric core complexes have fluorescence lifetimes nearly twice that of membranes with LH2 plus dimeric core complexes. This trend of increased lifetime is maintained with RCs in the open state as well, and for two different levels of LH2 content. Thus, energy trapping is more efficient when photosynthetic membranes of Rba. sphaeroides consist of RC-LH1-PufX dimers and LH2 complexes.</p>}},
author = {{Chenchiliyan, Manoop and Timpmann, Kõu and Jalviste, Erko and Adams, Peter G. and Hunter, C. Neil and Freiberg, Arvi}},
issn = {{0005-2728}},
keywords = {{LH1; LH2; Light harvesting; Photosynthesis; Photosynthetic excitons; RC}},
language = {{eng}},
number = {{6}},
pages = {{634--642}},
publisher = {{Elsevier}},
series = {{Biochimica et Biophysica Acta - Bioenergetics}},
title = {{Dimerization of core complexes as an efficient strategy for energy trapping in Rhodobacter sphaeroides}},
url = {{http://dx.doi.org/10.1016/j.bbabio.2016.03.020}},
doi = {{10.1016/j.bbabio.2016.03.020}},
volume = {{1857}},
year = {{2016}},
}