Change search
ReferencesLink to record
Permanent link

Direct link
Multiple Deletions of Small Cab-like Proteins in the Cyanobacterium Synechocystis sp. PCC 6803: CONSEQUENCES FOR PIGMENT BIOSYNTHESIS AND ACCUMULATION
Umeå University, Faculty of Science and Technology, Chemistry.
Umeå University, Faculty of Science and Technology, Chemistry.
2004 (English)In: Journal of Biological Chemistry, Vol. 279, no 27, 27971-9 p.Article in journal (Refereed) Published
Abstract [en]

Deletion of the genes for four or five small Cab-like proteins (SCPs) in photosystem (PS) I-less and PS I-less/PS II-less strains of Synechocystis sp. PCC 6803 caused a large decrease in the chlorophyll and carotenoid content of the cells without accumulation of early intermediates in the chlorophyll biosynthesis pathway, suggesting limited chlorophyll availability. The PS II/PS I ratio increased upon deletion of multiple SCPs in a wild type background, similar to what is observed in the presence of subsaturating concentrations of gabaculin, an inhibitor of an early step in the tetrapyrrole biosynthesis pathway. Upon deletion of multiple SCPs, neither 77 K fluorescence emission properties of phycobilisomeless thylakoids from the PS I-less/PS II-less strain nor the energy trapping efficiency of PS II were affected, indicating that under steady-state conditions SCPs do not bind much chlorophyll and do not serve as PS II antenna. Under conditions where protochlorophyllide reduction and thus chlorophyll synthesis were inhibited, chlorophyll disappeared quickly in a mutant lacking all five SCPs. This implies a role of SCPs in stabilization of chlorophyll-binding proteins and/or in reuse of chlorophylls. Under these conditions of inhibited reduction of protochlorophyllide, the accumulation kinetics of this intermediate were greatly altered in the absence of the five SCPs. This indicates an alteration of tetrapyrrole biosynthesis kinetics by SCPs. Based on this and other evidence, we propose that SCPs bind carotenoids and transiently bind chlorophyll, aiding in the supply of chlorophyll to nascent or reassembling photosynthetic complexes, and regulate the tetrapyrrole biosynthesis pathway as a function of the demand for chlorophyll.

Place, publisher, year, edition, pages
2004. Vol. 279, no 27, 27971-9 p.
URN: urn:nbn:se:umu:diva-13999DOI: doi:10.1074/jbc.M403307200OAI: diva2:153670
Available from: 2007-05-21 Created: 2007-05-21 Last updated: 2011-01-12Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Funk, Christiane
By organisation

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 22 hits
ReferencesLink to record
Permanent link

Direct link