The photosynthetic apparatus of Rhodopseudomonas palustris: structures and organization.
The structural analysis of the individual components of the photosynthetic apparatus of Rhodopseudomonas palustris, or those of related species, is almost complete. To shed light on the assembly and organization of this machinery, we have studied native membranes of Rps.palustris grown under different light conditions using atomic force microscopy (AFM). The organization of the complexes in the membranes is different from any previously observed: with areas of crystalline core-complexes, crystalline peripheral antennae, mixed domains, and apparently pure lipid membranes devoid of protein. Examination of antennae structure shows that chromatic adaptation is associated with modifications in absorption and size of the peripheral light harvesting complexes (LH2) as light intensity is reduced. The core-complex is observed to contain a reaction centre (RC) surrounded by an elliptical assembly of 15 LH1 subunits and a "gap" attributed to the W-subunit. The localization of the W-subunit is not restricted to the periapsis of the core-complex but randomly located with respect to the RC imposed axis.
Scheuring
Simon
S
Institut Curie, UMR-CNRS 168, 11 rue Pierre et Marie Curie, 75231 Paris Cedex 05, France. simon.scheuring@curie.fr
Gonçalves
Rui Pedro
RP
Prima
Valérie
V
Sturgis
James N
JN
D020130:Bacterial Chromatophores / Q000648:ultrastructure; D002462:Cell Membrane / Q000528:radiation effects / Q000648:ultrastructure; D008027:Light; D045342:Light-Harvesting Protein Complexes / Q000737:chemistry; D018625:Microscopy, Atomic Force; D010788:Photosynthesis; D012241:Rhodopseudomonas / Q000737:chemistry* / Q000528:radiation effects / Q000648:ultrastructure
D045342:Light-Harvesting Protein Complexes