Parallel subfunctionalisation of PsbO protein isoforms in angiosperms revealed by phylogenetic analysis and mapping of sequence variability onto protein structure
| Autor: | Lukáš Fischer, Miloš Duchoslav |
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| Rok vydání: | 2015 |
| Předmět: |
Models
Molecular Gene isoform Gene duplication Protein subunit Plant Science Biology Genes Plant Manganese-stabilizing protein (MSP) Protein Structure Secondary Magnoliopsida Open Reading Frames Protein structure Species Specificity Phylogenetics Botany Protein Isoforms Amino Acid Sequence Amino Acids GTPase Peptide sequence Phylogeny PsbO Phylogenetic tree Oxygen evolving complex Parallel evolution Photosystem II Protein Complex Protein tertiary structure Protein Structure Tertiary Open reading frame Amino Acid Substitution Evolutionary biology Homology modelling Research Article |
| Zdroj: | BMC Plant Biology |
| ISSN: | 1471-2229 |
| DOI: | 10.1186/s12870-015-0523-4 |
| Popis: | 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 Mn4CaO5 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. |
| Databáze: | OpenAIRE |
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