English   español  
Please use this identifier to cite or link to this item: http://hdl.handle.net/10261/8181
Share/Impact:
Statistics
logo share SHARE logo core CORE   Add this article to your Mendeley library MendeleyBASE

Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL | DATACITE
Exportar a otros formatos:

Title

Effect of carotenoid biosynthesis inhibition on the chlorosome organization in Chlorobium phaeobacteroides strain CL1401

AuthorsArellano, Juan B. ; Psencik, Jakub; Borrego, Carles M.; Ma, Ying-Zhong; Guyoneaud, Rémy; García-Gil, L. Jesús; Gillbro, Tomas
KeywordsCarotenoids
chlorosomes
Chlorobium phaeobacteroides
bacteriochlorophyll
isorenieratene
energy transfer
Issue DateJun-2000
PublisherWiley-Blackwell
CitationPhotochemistry and Photobiology (2000) 71:715-723
AbstractWe have studied the effect of the absence of carotenoids on the organization of bacteriochlorophylls (BChls) in chlorosomes of Chlorobium (Chl.) phaeobacteroides strain CL1401. Carotenoid-depleted chlorosomes were obtained by means of 2-hydroxybiphenyl–supplemented cultures. In the presence of the inhibitor, isorenieratene (Isr) and β-Isr biosynthesis were inhibited to more than 95%, leading to an accumulation of the colorless precursor phytoene inside the chlorosomes. In addition, there was a 30–40% decrease in the baseplate BChl a content. The absorption spectrum of the carotenoid-depleted chlorosomes showed a 10 nm blue shift in the BChl e Qy absorption peak. Under reducing conditions, a decrease in the BChl a/BChl e fluorescence emission ratio was observed in carotenoid-depleted chlorosomes relative to that in control chlorosomes, caused mainly by the decrease in the BChl a content. The steady-state fluorescence emission anisotropy in the BChl e region dropped from ;0.24 for native chlorosomes to ;0.14 for carotenoid-depleted ones, indicating reorganization of BChl e. The circular dichroism (CD) signal of the carotenoid-depleted chlorosomes was increased two times in the BChl e Qy region. A simple model based on the structure proposed was used to explain the observed effects. Carotenoids might affect the angle between the direction of the BChl e Qy transition and the axis of the rod. The orientation of BChl a in the baseplate remains unchanged in carotenoid-depleted chlorosomes, although there is a partial loss of BChl a as a consequence of a decrease in the baseplate size. The carotenoids are most likely rather close to the BChls and appear to be important for the aggregate structure in Chl. phaeobacteroides.
Publisher version (URL)http://www3.interscience.wiley.com/journal/119932103/abstract
URIhttp://hdl.handle.net/10261/8181
DOIhttp://dx.doi.org/10.1562/0031-8655(2000)0710715EOCBIO2.0.CO2
Appears in Collections:(IRNASA) Artículos
Files in This Item:
File Description SizeFormat 
Arellano et al 2000a.pdf294,43 kBAdobe PDFThumbnail
View/Open
Show full item record
Review this work
 


WARNING: Items in Digital.CSIC are protected by copyright, with all rights reserved, unless otherwise indicated.