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New insights into the molecular protein transport mechanism in bacteria published in the journal Nature Communications

The transport of proteins across biological membranes is essential for the viability of cells. In bacteria, two different pathways for the transport of proteins across the cytoplasmic membrane surrounding the cell interior are known. However, only one pathway, the so-called twin-arginine ("twin-arginine translocation" or TAT)-pathways has the amazing ability to transport folded proteins across the bacterial cytoplasmic membrane.

The close cooperation of Prof. Matthias Müller (Institute of Biochemistry and Molecular Biology, University of Freiburg) and Prof. Roland Freudl leading the group "Bacterial protein secretion" in the IBG-1 resulted in new insights into the molecular protein transport mechanism of this Tat-pathway. For instance, it could be shown that the protein TatC of the Tat-machinery has a catalytic activity as a signal peptide insertase in addition to its passive function as a receptor. This activity ensures that proteins to be transported are temporarily inserted into a specific substrate binding site after being recognized by TatC. This insertion represents an important prerequisite for the transport process.

These and other important results provide new insights into the molecular mechanism of Tat-dependent protein transport in bacteria. A manuscript covering these findings was recently published in the prestigious journal Nature Communications (

Graphic of protein transportOverview of the Tat-dependent pathway for the protein translocation in bacteria