Structural organisation of phycobilisomes from Synechocystis sp. strain PCC6803 and their interaction with the membrane.
Biochim Biophys Acta
; 1787(4): 272-9, 2009 Apr.
Article
em En
| MEDLINE
| ID: mdl-19344661
ABSTRACT
In cyanobacteria, the harvesting of light energy for photosynthesis is mainly carried out by the phycobilisome - a giant, multi-subunit pigment-protein complex. This complex is composed of heterodimeric phycobiliproteins that are assembled with the aid of linker polypeptides such that light absorption and energy transfer to photosystem II are optimised. In this work we have studied, using single particle electron microscopy, the phycobilisome structure in mutants lacking either two or all three of the phycocyanin hexamers. The images presented give much greater detail than those previously published, and in the best two-dimensional projection maps a resolution of 13 A was achieved. As well as giving a better overall picture of the assembly of phycobilisomes, these results reveal new details of the association of allophycocyanin trimers within the core. Insights are gained into the attachment of this core to the membrane surface, essential for efficient energy transfer to photosystem II. Comparison of projection maps of phycobilisomes with and without reconstituted ferredoxinNADP oxidoreductase suggests a location for this enzyme within the complex at the rod-core interface.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Membrana Celular
/
Ficobilissomas
/
Synechocystis
Idioma:
En
Revista:
Biochim Biophys Acta
Ano de publicação:
2009
Tipo de documento:
Article