Membrane binding of twin arginine preproteins as an early step in translocation.
The twin arginine transport (Tat) system translocates folded proteins across the bacterial inner membrane. Transport substrates are recognized by means of evolutionarily well-conserved N-terminal signal peptides. The precise role of signal peptides in the actual transport process is not yet fully understood. Potentially, much insight into the molecular details of the transport process could be gained from step-by-step in vitro experiments under controlled conditions. Here, we employ purified preproteins to study their interaction with the phospholipid membrane by using surface plasmon resonance spectroscopy. It turns out that preproteins interact tightly with a model membrane consisting of only phospholipids. This interaction, which is stabilized by both electrostatic and hydrophobic contributions, appears to constitute an early step in protein translocation by the Tat system.
Institute of Molecular Cell Biology, Department of Structural Biology, Vrije Universiteit, De Boelelaan 1087, 1081 HV Amsterdam, The Netherlands.
Anitha
A
Shanmugham
Harro W
HW
Wong Fong Sang
Yves J M
YJ
Bollen
Holger
H
Lill
D000595:Amino Acid Sequence; D001425:Bacterial Outer Membrane Proteins / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000378:metabolism*; D049452:Green Fluorescent Proteins; D008051:Lipid Bilayers / Q000378:metabolism; D008081:Liposomes / Q000378:metabolism; D008563:Membrane Lipids / Q000502:physiology; D026901:Membrane Transport Proteins / Q000378:metabolism*; D008567:Membranes, Artificial; D008969:Molecular Sequence Data; D011498:Protein Precursors / Q000378:metabolism*; D021382:Protein Sorting Signals / Q000502:physiology; D021381:Protein Transport / Q000502:physiology*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D016415:Sequence Alignment; D020349:Surface Plasmon Resonance
D001425:Bacterial Outer Membrane Proteins; D029968:Escherichia coli Proteins; D008051:Lipid Bilayers; D008081:Liposomes; D008563:Membrane Lipids; D026901:Membrane Transport Proteins; D008567:Membranes, Artificial; D011498:Protein Precursors; D021382:Protein Sorting Signals; D011993:Recombinant Fusion Proteins; C408585:twin-arginine translocase complex, E coli; D049452:Green Fluorescent Proteins; C078167:OMPA outer membrane proteins