Introduction of basic amino acid residues after the signal peptide inhibits protein translocation across the cytoplasmic membrane of Escherichia coli. Relation to the orientation of membrane proteins.
The introduction of positive charges at the amino terminus of the mature domain of secretory proteins resulted in strong inhibition of their translocation across the cytoplasmic membrane of Escherichia coli, both in vitro and in vivo. The model secretory proteins used were OmpF-Lpp chimeric proteins possessing a cleavable or uncleavable signal peptide, beta-lactamase (Bla) and Bla-Lpp chimeric proteins. It is suggested that positively charged residues preceding the hydrophobic domain of the signal peptide have a positive effect, and ones following the hydrophobic domain, a negative effect on the translocation. These findings are discussed in relation to the orientation of membrane proteins, of which positive charges are predominant on the cytoplasmic surface.
Yamane
K
K
Institute of Applied Microbiology, University of Tokyo, Japan.
Mizushima
S
S
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism*; D008962:Models, Theoretical; D008969:Molecular Sequence Data; D009154:Mutation; D015345:Oligonucleotide Probes; D010957:Plasmids; D011401:Promoter Regions, Genetic; D011499:Protein Processing, Post-Translational; D021382:Protein Sorting Signals / Q000235:genetics* / Q000378:metabolism; D013347:Subcellular Fractions / Q000378:metabolism
D001426:Bacterial Proteins; D008565:Membrane Proteins; D015345:Oligonucleotide Probes; D021382:Protein Sorting Signals