Charakterisierung von Proteinen des RNA-Metabolismus in Haloferax volcanii
FacultiesFakultät für Naturwissenschaften
LicenseStandard (Fassung vom 01.10.2008)
In this thesis three proteins in connection to the cellular RNA metabolism of the model archaeon H. volcanii were investigated for their biological functions. The first project focussed on gaining knowledge about the Lsm protein through generation and characterisation of a deletion mutant of the hvolsm gene as well as co-immunoprecipitation of potential interaction partners of the protein. While in Bacteria and Eukarya functions of the Sm/Lsm family of proteins are well understood, for the archaeal homologs only the typical ring-shaped structure and the characteristic binding to oligo(U) stretches could be shown thus far. This thesis research provides evidence that HvoLsm is not essential for cell survival. In addition, first co-immunoprecipitation experiments showed an interaction of HvoLsm with as yet unidentified RNA species as well as MS-analysed specific proteins. In another project the tRNA 3’ processing enzyme tRNase Z was investigated for its in vivo functions. Here, essentiality of this protein for survival of H. volcanii was verified, as a deletion of the hvotrz gene turned out to be lethal. Therefore the analysis of the biological function of this protein can only be achieved using different strategies (see Hölzle et al., 2008). In the last project dealing with the tRNase Z homolog NZ, it could be demonstrated that despite extensive in vitro and in vivo studies the function of this so far uncharacterised, unessential protein remains elusive. Nevertheless, several hints were obtained for an involvement of HvoNZ in the methylglyoxal metabolism or more specific the glyoxalase system as a glyoxalase II. Moreover, first results of co-immunoprecipitation experiments hint on a possible role in transcription regulation or even cell proliferation. Further analyses are necessary to account for the function and relevance of HvoNZ for the cell and possibly also for the evolution of the long version of the tRNase Z proteins.
Subject HeadingsArchaebakterien [GND]
Haloferax volcanii [GND]