  2.1.1.259 | evolution |
molecular evolution of the substrate specificity of chloroplastic aldolases/Rubisco lysine methyltransferases in plants, overview. The His-Ala/Pro-Trp triad located in the central part of LSMT enzymes is the key motif to confer the capacity to trimethylate Rubisco. Two of the critical residues are located on a surface loop outside the methyltransferase catalytic site. A strict correlation between the presence of the triad motif and the in vivo methylation status of Rubisco is observed, distribution of the motif into a phylogenetic tree, overview. Chloroplastic fructose-1,6-bisphosphate aldolases (FBAs) are naturally trimethylated in both Pisum sativum and Arabidopsis thaliana, whereas the Rubisco large subunit is trimethylated only in the former species. The distribution of the motif into a phylogenetic tree further suggests that the ancestral function of LSMT was FBA trimethylation. In a recent event during higher plant evolution, this function evolved in ancestors of Fabaceae, Cucurbitaceae, and Rosaceae to include Rubisco as an additional substrate to the archetypal enzyme |
757705 |
