[1] Max Planck Inst Biochem, Lab RNA Biol, D-82152 Martinsried, Germany
[2] Univ Regensburg, D-93053 Regensburg, Germany
[3] Univ Munich, Sect Evolutionary Biol, Dept Biol 2, D-82152 Planegg Martinsried, Germany
[4] Fritz Lipmann Inst eV, Leibniz Inst Age Res, D-07745 Jena, Germany
[5] Max Planck Inst Biochem, Dept Mol Med, D-82152 Martinsried, Germany