RNABIC · Structure, assembly and metal ion binding properties of the catalytic core of a group II intron ribozyme

Group II introns are one class of naturally occurring catalytic RNAs, ranging between 600 and thousands of nucleotides in length. These ribozymes catalyze a variety of reactions, among which the self splicing activity is the most prominent one. These large molecular machines are found primarily in organellar genes of plants, fungi and lower eukaryotes, but also in many bacteria. Metal ions are crucial for folding and activity of catalytic RNA molecules, however their structural and mechanicistic roles are poorly understood. Many biochemical studies have been performed in the past, but few structural information is available on group II intron ribozymes. Here we plan to structurally characterize by NMR the kappa-zeta region of domain 1 of the group IIB intron Sc.ai5gamma, originating from the cox1 gene in yeast mitochondria, both in the absence and presence of metal ions, in addition to investigate its docking to domain 5. The kappa-zeta region is the most central part of these ribozymes as not only it represents the nucleation core of intron folding but its complex with domain 5 comprises the largest part of the catalytic core. This dual role underlines the significance of any new information on structure, metal ion binding and domain assembly gained of these fascinating molecules, which are considered ancestors not only of the spliceosome but also of large part of the eukaryotic genome. Belonging to action 2 of the FP7 “Work Program-PEOPLE” this project intends to train an experienced researcher in the (for her) novel fascinating field of “Coordination Chemistry of nucleic acids”, a field at the interface between Chemistry and Life Science, two different Marie Curie panels.