Characterization of the diversification of phospholipid:diacylglycerol acyltransferases in the green lineage

摘要: Triacylglycerols have important physiological roles in photosynthetic organisms, and are widely used as food, feed industrial materials our daily life. Phospholipid:diacylglycerol acyltransferase (PDAT) is the pivotal enzyme catalyzing acyl-CoA-independent biosynthesis of triacylglycerols, which unique plants, algae fungi, but not animals, has essential functions plant algal growth, development stress responses. Currently, this yet to be examined an evolutionary context at level green lineage. Some fundamental questions remain unanswered, such how PDATs evolved organisms whether evolution terrestrial from a lineage charophyte diverges function. As such, we molecular analysis biochemical assays address these questions. Our results indicated that PDAT underwent divergent lineage: exist wide range plants algae, cyanobacteria. Although exhibit conservation several features, phylogenetic selection-pressure analyses revealed overall they highly divergent, driven by different selection constraints. Positive selection, one major driving force, may resulted enzymes with higher functional importance land than algae. Further structural mutagenesis demonstrated some amino acid sites under positive critically structure function, central lecithin:cholesterol family general.