title: A functional prolipoprotein signal peptide with a deletion of four amino acid residues from the hydrophobic region.
abstract: The deletion of several codons within the signal sequence coding region of the Escherichia coli lipoprotein gene has been accomplished by oligonucleotide-directed site-specific mutagenesis. The deletion of the Leu-13 residue in a mutant in which two glycine residues had previously been deleted from the hydrophobic region (Inouye, S., Vlasuk, G., Hsiung, H., and Inouye, M. (1984) J. Biol. Chem. 259, 3729-3733) was found to cause the accumulation of the unmodified form of the protein in the cytoplasm and cytoplasmic membrane. This mutation also caused a cessation in cell growth within 15 min after synthesis of the mutant protein was induced. A deletion of the Val-7 residue was capable of suppressing the effect of the Leu-13 deletion when both are present. However, by itself the Val-7 deletion appeared to have little effect on the glycine mutant. The ability of the signal sequence to mediate the secretion of the protein after the deletion of 4 residues from the hydrophobic region demonstrates a surprising degree of flexibility in the length of this region. The deletion mutations were also found to have an unusual effect on the rate of synthesis of lipoprotein.
mesh_terms: D000595:Amino Acid Sequence; D001425:Bacterial Outer Membrane Proteins / Q000096:biosynthesis* / Q000235:genetics; D001483:Base Sequence; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000235:genetics; D029968:Escherichia coli Proteins; D008074:Lipoproteins; D009154:Mutation; D010455:Peptides / Q000032:analysis*; D011498:Protein Precursors / Q000096:biosynthesis* / Q000235:genetics; D021382:Protein Sorting Signals
chemical_list: D001425:Bacterial Outer Membrane Proteins; D029968:Escherichia coli Proteins; D008074:Lipoproteins; C099932:Lpp protein, E coli; D010455:Peptides; D011498:Protein Precursors; D021382:Protein Sorting Signals