Ribonucleases

All RNA molecules are transcribed into precursor RNAs and have to undergo a variety of processing events to become functional RNAs. In addition, they also have to undergo controlled degradation. The generation and regulated turnover of these RNA molecules is catalysed by ribonucleases. Only few of these important enzymes have been identified in Archaea. Therefore we are investigating and identifying new ribonucleases and are characterising them using in vitro and in vivo methods in Haloarchaea.

We isolated the tRNA processing enzyme tRNase Z and are currently characterising this enzyme in detail. In addition, we investigate the mRNA 3'-end processing protein CPSF, the RNase G/E, the RppH protein and RNase J. To learn more about the evolution of these ribonucleases we compare them to their eukaryotic counterparts in yeast and plants.

The different steps from a tRNA precursor molecule to a functional tRNA molecule are shown. The precursor contains additional sequences which have to be cut or cut out by diffenrent enzymes (RNase P, splicing endonuclease, tRNase Z) and the CCA sequence has to be added to the tRNA 3´ end by another enzyme (nucleotidyl transferase). — The maturation steps required to generate a functional tRNA molecule are shown. The precursor contains additional sequences which have to be removed by endonucleases (RNase P, splicing endonuclease and tRNase Z) and the CCA sequence has to be added to the tRNA 3´ end by the nucleotidyl transferase.