A1 Refereed original research article in a scientific journal
Substantial deletions in the DE loop of the photosystem II D1 protein do not prevent its turnover or cross-linking with the alpha-subunit of cytochrome b559. A study using Synechocystis sp PCC 6803 mutants
Authors: Barbato R, Mulo P, Bergo E, Carbonera D, Maenpaa P, Giacometti GM, Barber J, Aro EM
Publisher: GUSTAV FISCHER VERLAG
Publication year: 1999
Journal: Journal of Plant Physiology
Journal name in source: JOURNAL OF PLANT PHYSIOLOGY
Journal acronym: J PLANT PHYSIOL
Volume: 154
Issue: 5-6
First page : 591
Last page: 596
Number of pages: 6
ISSN: 0176-1617
DOI: https://doi.org/10.1016/S0176-1617(99)80231-4
Abstract
Light-induced damage of photosystem II brings about the specific degradation of the reaction centre D1-protein. Under similar conditions, cross-linking occurs between this protein and the alpha-subunit of cytochrome b559, giving rise to a 41-kDa adduct. In order to understand whether there is any relationship between the formation of the 41-kDa adduct and the D1-protein degradation, three deletion mutants of Synechocystis sp. PCC 6803 have been employed. The three mutants have deletions in the DE loop of the D1-protein, Delta(G240-V249), Delta(R225-F239) and Delta(R225-V249), which incorporates the < PEST-like > region and the FGQEEET motif. These regions have been implicated in the degradation and turnover of the D1 protein, and also in the formation of the 41-kDa adduct. Using a proteolytic digestion assay we show that the deletions induce conformational changes in the putative helical region of the DE-loop. However, the deletion mutants mantain their abilities to degrade and turnover the D1 protein, and also to generate the 41-kDa adduct, reinforcing the idea of a correlation between the two phenomena.
Light-induced damage of photosystem II brings about the specific degradation of the reaction centre D1-protein. Under similar conditions, cross-linking occurs between this protein and the alpha-subunit of cytochrome b559, giving rise to a 41-kDa adduct. In order to understand whether there is any relationship between the formation of the 41-kDa adduct and the D1-protein degradation, three deletion mutants of Synechocystis sp. PCC 6803 have been employed. The three mutants have deletions in the DE loop of the D1-protein, Delta(G240-V249), Delta(R225-F239) and Delta(R225-V249), which incorporates the < PEST-like > region and the FGQEEET motif. These regions have been implicated in the degradation and turnover of the D1 protein, and also in the formation of the 41-kDa adduct. Using a proteolytic digestion assay we show that the deletions induce conformational changes in the putative helical region of the DE-loop. However, the deletion mutants mantain their abilities to degrade and turnover the D1 protein, and also to generate the 41-kDa adduct, reinforcing the idea of a correlation between the two phenomena.
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