Title data
Brotosudarmo, Tatas H. P. ; Kunz, Ralf ; Böhm, Paul S. ; Gardiner, Alastair T. ; Moulisová, Vladimira ; Cogdell, Richard J. ; Köhler, Jürgen:
Single-molecule spectroscopy reveals that individual low-light LH2 complexes from Rhodopseudomonas palustris 2.1.6. have a heterogeneous polypeptide composition.
In: Biophysical Journal.
Vol. 97
(2009)
Issue 5
.
- pp. 1491-1500.
ISSN 1542-0086
DOI: https://doi.org/10.1016/j.bpj.2009.06.034
Abstract in another language
Rhodopseudomonas palustris belongs to the group of purple bacteria that have the ability to produce LH2 complexes with unusual absorption spectra when they are grown at low-light intensity. This ability is often related to the presence of multiple genes encoding the antenna apoproteins. Here we report, for the first time to our knowledge, direct evidence that individual low-light LH2 complexes have a heterogeneous alphabeta-apoprotein composition that modulates the site energies of Bchl a molecules, producing absorption bands at 800, 820, and 850 nm. The arrangement of the Bchl a molecules in the "tightly coupled ring" can be modeled by nine alphabeta-Bchls dimers, such that the Bchls bound to six alphabeta-pairs have B820-like site energies and the remaining Bchl a molecules have B850-like site energies. Furthermore, the experimental data can only be satisfactorily modeled when these six alphabeta-pairs with B820 Bchl a molecules are distributed such that the symmetry of the assembly is reduced to C(3). It is also clear from the measured single-molecule spectra that the energies of the electronically excited states in the mixed B820/850 ring are mainly influenced by diagonal disorder.
Further data
Item Type: | Article in a journal |
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Refereed: | Yes |
Institutions of the University: | Faculties > Faculty of Mathematics, Physics und Computer Science > Department of Physics > Chair Experimental Physics IX - Spectroscopy of Soft Matter > Chair Experimental Physics IX - Spectroscopy of Soft Matter - Univ.-Prof. Dr. Jürgen Köhler Faculties Faculties > Faculty of Mathematics, Physics und Computer Science Faculties > Faculty of Mathematics, Physics und Computer Science > Department of Physics Faculties > Faculty of Mathematics, Physics und Computer Science > Department of Physics > Chair Experimental Physics IX - Spectroscopy of Soft Matter |
Result of work at the UBT: | Yes |
DDC Subjects: | 500 Science > 530 Physics |
Date Deposited: | 10 Apr 2018 12:15 |
Last Modified: | 12 Jan 2023 07:21 |
URI: | https://eref.uni-bayreuth.de/id/eprint/43280 |