OPEN ACCESS ARTICLE

This Article Free via Open Access: OA OA Full Text Full Text (PDF) Supplemental Data OA All Versions of this Article: 145/4/1681    most recent pp.107.107805v1 Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Dobáková, M. Articles by Komenda, J. Search for Related Content PubMed PubMed Citation Articles by Dobáková, M. Articles by Komenda, J. Agricola Articles by Dobáková, M. Articles by Komenda, J.

BIOENERGETICS AND PHOTOSYNTHESIS

Role of the PsbI Protein in Photosystem II Assembly and Repair in the Cyanobacterium Synechocystis sp. PCC 6803^1,[W],[OA]

Marika Dobáková, Martin Tich and Josef Komenda^*

Institute of Microbiology, Academy of Sciences, 37981 Tebo, Czech Republic; and Institute of Physical Biology, University of South Bohemia, 37333 Nové Hrady, Czech Republic

The involvement of the PsbI protein in the assembly and repair of the photosystem II (PSII) complex has been studied in the cyanobacterium Synechocystis sp. PCC 6803. Analysis of PSII complexes in the wild-type strain showed that the PsbI protein was present in dimeric and monomeric core complexes, core complexes lacking CP43, and in reaction center complexes containing D1, D2, and cytochrome b-559. In addition, immunoprecipitation experiments and the use of a histidine-tagged derivative of PsbI have revealed the presence in the thylakoid membrane of assembly complexes containing PsbI and either the precursor or mature forms of D1. Analysis of PSII assembly in the psbI deletion mutant and in strains lacking PsbI together with other PSII subunits showed that PsbI was not required for formation of PSII reaction center complexes or core complexes, although levels of unassembled D1 were reduced in its absence. However, loss of PsbI led to a dramatic destabilization of CP43 binding within monomeric and dimeric PSII core complexes. Despite the close structural relationship between D1 and PsbI in the PSII complex, PsbI turned over much slower than D1, whereas high light-induced turnover of D1 was accelerated in the absence of PsbI. Overall, our results suggest that PsbI is an early assembly partner for D1 and that it plays a functional role in stabilizing the binding of CP43 in the PSII holoenzyme.

The author responsible for distribution of materials integral to the findings presented in this article in accordance with the policy described in the Instructions for Authors (www.plantphysiol.org) is: Josef Komenda (komenda{at}alga.cz).

^[W] The online version of this article contains Web-only data.

^[OA] Open Access articles can be viewed online without a subscription.

www.plantphysiol.org/cgi/doi/10.1104/pp.107.107805

^* Corresponding author; e-mail komenda{at}alga.cz.

Received August 21, 2007; accepted September 26, 2007; published October 5, 2007.

This article has been cited by other articles:

				R. Sobotka, U. Duhring, J. Komenda, E. Peter, Z. Gardian, M. Tichy, B. Grimm, and A. Wilde Importance of the Cyanobacterial Gun4 Protein for Chlorophyll Metabolism and Assembly of Photosynthetic Complexes J. Biol. Chem., September 19, 2008; 283(38): 25794 - 25802. [Abstract] [Full Text] [PDF]

				J. Komenda, J. Nickelsen, M. Tichy, O. Prasil, L. A. Eichacker, and P. J. Nixon The Cyanobacterial Homologue of HCF136/YCF48 Is a Component of an Early Photosystem II Assembly Complex and Is Important for Both the Efficient Assembly and Repair of Photosystem II in Synechocystis sp. PCC 6803 J. Biol. Chem., August 15, 2008; 283(33): 22390 - 22399. [Abstract] [Full Text] [PDF]