Refinement of the x-ray structure of the RC LH1 core complex from Rhodopseudomonas palustris by single-molecule spectroscopy.
A unique combination of single-molecule spectroscopy with numerical simulations has allowed us to achieve a refined structural model for the bacteriochlorophyll a (BChl a) pigment arrangement in reaction center-light-harvesting 1 core complexes of Rhodopseudomonas palustris. Details in the optical spectra, such as spectral separation and mutual polarizations of spectral bands, are compared with results from numerical simulations for various models of the BChl a arrangement that were all well within the 4.8-A limit of the accuracy of the available x-ray structure. The experimental data are consistent with a geometry where 15 BChl a dimers, each taken homologous to those from light-harvesting 2 complex from Rhodopseudomonas acidophila, are arranged in an overall elliptical structure featuring a gap on the long side of the ellipse.
Richter
Martin F
MF
Experimental Physics IV and Bayreuth Institute for Macromolecular Research, Universität Bayreuth, Universtitätsstrasse 30, D-95440 Bayreuth, Germany.
Baier
Jürgen
J
Southall
June
J
Cogdell
Richard J
RJ
Oellerich
Silke
S
Köhler
Jörgen
J
D001426:Bacterial Proteins / Q000737:chemistry*; D025541:Bacteriochlorophyll A / Q000737:chemistry*; D005453:Fluorescence; D045331:Photosystem I Protein Complex / Q000737:chemistry*; D011487:Protein Conformation; D012241:Rhodopseudomonas / Q000201:enzymology*; D014965:X-Rays
D001426:Bacterial Proteins; D025541:Bacteriochlorophyll A; D045331:Photosystem I Protein Complex