Charakterisierung der Prozessierungs-und Interferenzaktivität des CRISPR/Cas-Systems in Haloferax volcanii
FacultiesFakultät für Naturwissenschaften
The CRISPR/Cas-system represents an adaptive, heritable immune system found in prokaryotes to defend themselves against viruses and other invasive genetic elements. An essential part of this system is the biogenesis of small RNA molecules, so called crRNAs, which mediate the specificity during the degradation of foreign nucleic acids. This thesis deals with the characterization of these crRNA processing events in the archaeal model organism Haloferax volcanii. To be able to detect proteins of the CRISPR/Cas-system, polyclonal antibodies against the proteins Cas5, Cas6 and Cas7 were obtained by the immunization of mice. Moreover, it was investigated by in vivo and in vitro studies, which Cas-proteins are required for the processing and stabilization of the crRNA and whether these proteins interact with each other in a complex. By mutational analysis of the Cas6 protein several amino acid residues were identified which are essential for the function of the protein. At last, the processing- and crRNA-binding activity of Cas6 from the bacterium Caldicellulosiruptor lactoaceticus was analyzed in vitro. Here it was shown that this protein interacts with repeat-RNA, but does not cleave it.
Subject HeadingsHaloferax volcanii [GND]
Interferenz <Genetik> [GND]
RNA processing, post-transcriptional [MeSH]