Transmembrane insertion of twin-arginine signal peptides is driven by TatC and regulated by TatB

• DOI: 10.1038/ncomms2308
• Publication Date: 2012-12-18T09:50:06Z
• Authors: Julia Fröbel; Patrick Rose; Frank Lausberg; Anne-Sophie Blümmel; Roland Freudl; Matthias Müller
• Keywords: Twin-arginine translocation pathway; TATB; SIGNAL (programming language)

The twin-arginine translocation (Tat) pathway of bacteria and plant chloroplasts mediates the transmembrane transport folded proteins, which harbour signal sequences with a conserved motif. Many Tat translocases comprise three membrane proteins TatA, TatB TatC. TatC was previously shown to be involved in recognizing peptides. Here we show that beyond recognition, insertion sequence, thereby translocating sequence cleavage site across bilayer. In absence TatB, this can lead removal even from translocation-incompetent substrate. Hence interaction peptides counteracts their premature uncoupled translocation. This capacity is not shared by homologous TatA protein. Collectively our results suggest an insertase for translocation-proficient recognition requires concerted action TatB. B C act together translocate bacterial chloroplast membranes, however precise mechanism remains unclear. Fröbel colleagues discover has unforeseen activity, while prevents before