Internal structure of chlorosomes from brown-colored Chlorobium species and the role of carotenoids in their assembly

Chlorosomes are the main light harvesting complexes of green photosynthetic bacteria. Recently, a lamellar model was proposed for the arrangement of pigment aggregates in Chlorobium tepidum chlorosomes, which contain bacteriochlorophyll (BChl) c as the main pigment. Here we demonstrate that the lame...

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Detalles Bibliográficos
Autores: Psencik, Jakub, Arellano, Juan B., Ikonen, Teemu P., Borrego i Moré, Carles, Laurinmaki, Pasi A., Butcher, Sarah J., Serimaa, Ritva E., Tuma, Roman
Tipo de recurso: artículo
Fecha de publicación:2006
País:España
Institución:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
Repositorio:Recercat. Dipósit de la Recerca de Catalunya
OAI Identifier:oai:recercat.cat:10256/3563
Acceso en línea:http://hdl.handle.net/10256/3563
Access Level:acceso abierto
Palabra clave:Bacteris fotosintetitzadors
Carotenoides
Pigments fotosintètics
Carotenoids
Photosynthetic bacteria
Photosynthetic pigments
Descripción
Sumario:Chlorosomes are the main light harvesting complexes of green photosynthetic bacteria. Recently, a lamellar model was proposed for the arrangement of pigment aggregates in Chlorobium tepidum chlorosomes, which contain bacteriochlorophyll (BChl) c as the main pigment. Here we demonstrate that the lamellar organization is also found in chlorosomes from two brown-colored species (Chl. phaeovibrioides and Chl. phaeobacteroides) containing BChl e as the main pigment. This suggests that the lamellar model is universal among green sulfur bacteria. In contrast to green-colored Chl. tepidum, chlorosomes from the brown-colored species often contain domains of lamellar aggregates that may help them to survive in extremely low light conditions. We suggest that carotenoids are localized between the lamellar planes and drive lamellar assembly by augmenting hydrophobic interactions. A model for chlorosome assembly, which accounts for the role of carotenoids and secondary BChl homologs, is presented