English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Background  PsbO, the manganese-stabilising protein, is an indispensable extrinsic subunit of photosystem II. It plays a crucial role in the stabilisation of the water-splitting Mn 4 CaO 5  cluster, which catalyses the oxidation of water to molecular oxygen by using light energy. PsbO was also demonstrated to have a weak GTPase activity that could be involved in regulation of D1 protein turnover. Our analysis of  psbO  sequences showed that many angiosperm species express two  psbO  paralogs, but the pairs of isoforms in one species were not orthologous to pairs of isoforms in distant species.    Results  Phylogenetic analysis of 91  psbO  sequences from 49 land plant species revealed that  psbO  duplication occurred many times independently, generally at the roots of modern angiosperm families. In spite of this, the level of isoform divergence was similar in different species. Moreover, mapping of the differences on the protein tertiary structure showed that the isoforms in individual species differ from each other on similar positions, mostly on the luminally exposed end of the β-barrel structure. Comparison of these differences with the location of differences between PsbOs from diverse angiosperm families indicated various selection pressures in PsbO evolution and potential interaction surfaces on the PsbO structure.    Conclusions  The analyses suggest that similar subfunctionalisation of PsbO isoforms occurred parallelly in various lineages. We speculate that the presence of two PsbO isoforms helps the plants to finely adjust the photosynthetic apparatus in response to variable conditions. This might be mediated by diverse GTPase activity, since the isoform differences predominate near the predicted GTP-binding site.    Electronic supplementary material  The online version of this article (doi:10.1186/s12870-015-0523-4) contains supplementary material, which is available to authorized users.

bmc plant biology

Parallel subfunctionalisation of PsbO protein isoforms in angiosperms revealed by phylogenetic analysis and mapping of sequence variability onto protein structure