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The targeting pathway of Escherichia coli presecretory and integral membrane proteins is specified by the hydrophobicity of the targeting signal.
| Content Provider | Semantic Scholar |
|---|---|
| Author | Lee, Hin C. Bernstein, Harris D. |
| Copyright Year | 2001 |
| Abstract | Previous studies have demonstrated that presecretory proteins such as maltose binding protein (MBP) and outer membrane protein A (OmpA) are targeted to the Escherichia coli inner membrane by the molecular chaperone SecB, but that integral membrane proteins are targeted by the signal recognition particle (SRP). In vitro studies have suggested that trigger factor binds to a sequence near the N terminus of the mature region of OmpA and shunts the protein into the SecB pathway by blocking an interaction between SRP and the signal peptide. By contrast, we have found that the targeting pathway of a protein under physiological conditions is dictated by the composition of its targeting signal. Replacement of the MBP or OmpA signal peptide with the first transmembrane segment of AcrB abolished the dependence on SecB for transport and rerouted both proteins into the SRP targeting pathway. More modest alterations of the MBP signal peptide that simply increase its hydrophobicity also promoted SRP binding. Furthermore, we obtained evidence that SRP has a low affinity for typical signal peptides in vivo. These results imply that different classes of E. coli proteins are targeted by distinct pathways because bacterial SRP binds to a more restricted range of targeting signals than its eukaryotic counterpart. |
| Starting Page | 570 |
| Ending Page | 570 |
| Page Count | 1 |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | http://www.pnas.org/content/98/6/3471.full.pdf |
| PubMed reference number | 11248102v1 |
| Volume Number | 98 |
| Issue Number | 6 |
| Journal | Proceedings of the National Academy of Sciences of the United States of America |
| Language | English |
| Access Restriction | Open |
| Subject Keyword | Affinity Class Integral Membrane Proteins Maltose-Binding Proteins Molecular Chaperones OMPA outer membrane proteins Signal Peptides Signal Recognition Particle Staphylococcal Protein A Tissue membrane cellular targeting maltose binding |
| Content Type | Text |
| Resource Type | Article |
