A chemically cross-linked nonlinear proOmpA molecule can be translocated into everted membrane vesicles of Escherichia coli in the presence of the proton motive force.
The chemical cross-linking between the two cysteine residues at positions + 290 and + 302 of proOmpA was performed with N,N'-bis(3-maleimidopropionyl)-2-hydroxy-1,3-propanediamine. In the absence of the proton motive force (delta muH+), the cross-linked proOmpA was only partially translocated into everted membrane vesicles, leading to accumulation of translocation intermediates. In the presence of delta mu H+, the cross-linked proOmpA was completely translocated. The translocated OmpA still possessed the cross-linked loop composed of 13 amino acid residues and the cross-linker. It is concluded that polypeptide chains need not be necessarily linear and fully expanded to be translocated.
Tani
K
K
Institute of Applied Microbiology, University of Tokyo, Japan.
Mizushima
S
S
D000595:Amino Acid Sequence; D001425:Bacterial Outer Membrane Proteins / Q000378:metabolism*; D001693:Biological Transport, Active; D002462:Cell Membrane / Q000378:metabolism; D002474:Cell-Free System; D003432:Cross-Linking Reagents; D003545:Cysteine / Q000378:metabolism; D003959:Diamines; D004926:Escherichia coli / Q000378:metabolism*; D005089:Exocytosis / Q000502:physiology*; D008301:Maleimides; D008969:Molecular Sequence Data; D011487:Protein Conformation; D011522:Protons; D012697:Serine Endopeptidases / Q000378:metabolism
D001425:Bacterial Outer Membrane Proteins; D003432:Cross-Linking Reagents; D003959:Diamines; D008301:Maleimides; D011522:Protons; C069702:N,N'-bis(3-maleimidepropionyl)-2-hydroxy-1,3-propanediamine; D012697:Serine Endopeptidases; C036813:lysyl endopeptidase; D003545:Cysteine