Phosphatidylethanolamine mediates insertion of the catalytic domain of leader peptidase in membranes.
Leader peptidase is an integral membrane protein of E. coli and it catalyses the removal of most signal peptides from translocated precursor proteins. In this study it is shown that when the transmembrane anchors are removed in vivo, the remaining catalytic domain can bind to inner and outer membranes of E. coli. Furthermore, the purified catalytic domain binds to inner membrane vesicles and vesicles composed of purified inner membrane lipids with comparable efficiency. It is shown that the interaction is caused by penetration of a part of the catalytic domain between the lipids. Penetration is mediated by phosphatidylethanolamine, the most abundant lipid in E. coli, and does not seem to depend on electrostatic interactions. A hydrophobic segment around the catalytically important residue serine 90 is required for the interaction with membranes.
Department Biochemistry of Membranes, Centre for Biomembranes and Lipid Enzymology, Utrecht University, The Netherlands. w.klompenburg@biol.rug.nl
W
W
van Klompenburg
M
M
Paetzel
J M
JM
de Jong
R E
RE
Dalbey
R A
RA
Demel
G
G
von Heijne
B
B
de Kruijff
D000595:Amino Acid Sequence; D001665:Binding Sites; D001692:Biological Transport; D002384:Catalysis; D002462:Cell Membrane / Q000378:metabolism; D004926:Escherichia coli / Q000378:metabolism; D008051:Lipid Bilayers / Q000378:metabolism; D008563:Membrane Lipids / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism*; D008969:Molecular Sequence Data; D010714:Phosphatidylethanolamines / Q000378:metabolism*; D011485:Protein Binding; D012697:Serine Endopeptidases / Q000378:metabolism*
D008051:Lipid Bilayers; D008563:Membrane Lipids; D008565:Membrane Proteins; D010714:Phosphatidylethanolamines; D012697:Serine Endopeptidases; C026515:type I signal peptidase