The type-IV secretion system (T4SS) is a machinery able to transfer DNA and proteins between bacteria and in certain cases also to eukaryotic cells. This thesis compared the T4SSs present in... Show moreThe type-IV secretion system (T4SS) is a machinery able to transfer DNA and proteins between bacteria and in certain cases also to eukaryotic cells. This thesis compared the T4SSs present in Agrobacterium tumefaciens and the conjugative plasmid RP4. A. tumefaciens is able to transfer DNA into plant cells and transform them genetically. We discovered that a novel hairpin structure on the terminus of the transferred DNA allows for earlier expression of its genes in the recipient plant cell. Further, we could describe the translocation signal of the relaxase protein TraI of RP4 responsible for DNA processing and transfer via the T4SS. Additionally, it was shown that the T4SS of RP4 is able to translocate proteins from one cell to another without parallel DNA transfer. Furthermore, we were able to create a hybrid relaxase created consisting of parts from A. tumefaciens (relaxase part) and RP4 (translocation signal) that was shown to be translocated via the T4SS of RP4. Show less
