Metal ions in the catalytic core of group II intron ribozymes

Group II introns are ribozymes that are found primarily in organellar genes of plants, fungi, and yeast, but also in a number of bacteria. They comprise roughly 600-2500 nucleotide units, which fold into a complex three-dimensional structure that is arranged around a central wheel (see Figure). Group II introns catalyse their self-excision, as well as RNA and DNA hydrolysis and intron mobility into RNA and DNA substrates. Due to their size, the conserved secondary and compact tertiary structure, and their interesting phylogenetic role, they are a rich source of information on different RNA structures and motifs. Metal ions are inextricably involved in folding, formation of such local motifs and catalysis.

By NMR, we determine the solution structures of domains part of the catalytic core, followed by the characterisation of their metal ion binding properties. Single-molecule FRET experiments are performed on the almost full-length ribozyme in order to investigate cation-dependent folding and long-range tertiary interactions.

Group members involved: Daniela Donghi, Erica Fiorini, Melodie Hadzic, Mokrane Khier, Sebastian Koenig, Danny Kowerko, Maria Pechlaner, Miriam Skilandat

Further reading:

• Angew. Chem. Int. Ed., 2009, 48, 9739-9742
• J. Inorg. Biochem., 2008, 102, 2147-2154
• Proc. Nat. Ac. Sci., 2008, 105, 13853–13858
• J. Biol. Inorg. Chem., 2008, 13, 1025-1036
• ChemBioChem, 2007, 8/3, 306-314