Diversity and evolution of phycobilisomes in marine Synechococcus spp.: a comparative genomics study
Six, Christophe, Thomas, Jean-Claude , Garczarek, Laurence, Ostrowski, Martin, Dufresne, Alexis , Blot, Nicolas, Scanlan, David J. and Partensky, Frédéric. (2007) Diversity and evolution of phycobilisomes in marine Synechococcus spp.: a comparative genomics study. Genome Biology, Vol.8 (No.12). ISSN 1474-7596
WRAP_Scanlan_Diversity_evolution.pdf - Requires a PDF viewer such as GSview, Xpdf or Adobe Acrobat Reader
Official URL: http://dx.doi.org/10.1186/gb-2007-8-12-r259
Marine Synechococcus owe their specific vivid color (ranging from blue-green to orange) to their large extrinsic antenna complexes called phycobilisomes, comprising a central allophycocyanin core and rods of variable phycobiliprotein composition. Three major pigment types can be defined depending on the major phycobiliprotein found in the rods (phycocyanin, phycoerythrin I or phycoerythrin II). Among strains containing both phycoerythrins I and II, four subtypes can be distinguished based on the ratio of the two chromophores bound to these phycobiliproteins. Genomes of eleven marine Synechococcus strains recently became available with one to four strains per pigment type or subtype, allowing an unprecedented comparative genomics study of genes involved in phycobilisome metabolism.
By carefully comparing the Synechococcus genomes, we have retrieved candidate genes potentially required for the synthesis of phycobiliproteins in each pigment type. This includes linker polypeptides, phycobilin lyases and a number of novel genes of uncharacterized function. Interestingly, strains belonging to a given pigment type have similar phycobilisome gene complements and organization, independent of the core genome phylogeny (as assessed using concatenated ribosomal proteins). While phylogenetic trees based on concatenated allophycocyanin protein sequences are congruent with the latter, those based on phycocyanin and phycoerythrin notably differ and match the Synechococcus pigment types.
We conclude that the phycobilisome core has likely evolved together with the core genome, while rods must have evolved independently, possibly by lateral transfer of phycobilisome rod genes or gene clusters between Synechococcus strains, either via viruses or by natural transformation, allowing rapid adaptation to a variety of light niches.
|Item Type:||Journal Article|
|Subjects:||Q Science > QK Botany
Q Science > QR Microbiology
|Divisions:||Faculty of Science > Life Sciences (2010- ) > Biological Sciences ( -2010)|
|Library of Congress Subject Headings (LCSH):||Cyanobacterial blooms, Gene mapping, Phycobilisomes|
|Journal or Publication Title:||Genome Biology|
|Publisher:||BioMed Central Ltd.|
|Official Date:||5 December 2007|
|Access rights to Published version:||Open Access|
|Funder:||Natural Environment Research Council (Great Britain) (NERC), France. Agence nationale de la recherche (ANR), European Commission (EC)|
|Grant number:||NE/C000536/1 (NERC)|
1. Johnson PW, Sieburth JM: Chroococcoid cyanobacteria in the
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