Genetic studies on mechanisms of protein localization in escherichia coli K‐12
- 1 January 1980
- journal article
- review article
- Published by Wiley in Journal of Supramolecular Structure
- Vol. 13 (2), 147-163
- https://doi.org/10.1002/jss.400130203
Abstract
In the last few years, several laboratories have demonstrated that many proteins (both from eukaryotic and prokaryotic organisms) that are destined to be localized in noncytoplasmic locations initially are synthesized as a precursor with a 15–30 amino acid extension at the NH2-terminal end of the molecule. This extra peptide has been termed the signal sequence, and it has been proposed that this signal plays a role in the localization of the extracytoplasmic protein. We are studying the process by which proteins are exported to the envelope region of Escherichia coli. Our work deals primarily with the outer membrane proteins, λ receptor, the product of the lamB gene, and the major outer membrane (porin) proteins 1a and 1b, products of the ompF and ompC genes. Using techniques of gene fusion, we have demonstrated that information specifying the cellular location of the λ receptor is contained within the lamB gene. Furthermore, we have shown that this information is capable of directing even a normally cytoplasmic protein, β-galactosidase, to the outer membrane. Some of this information is contained within the signal sequence. Mutations that alter this sequence prevent export of the λ receptor protein. Again using techniques of gene fusion, we have shown that the signal sequence alone is not sufficient to cause export of β-galactosidase from the cytoplasm. Other information within the lamB gene is required. Selection procedures have been developed to isolate mutations that exhibit a general alteration in the export process. Genetic analysis of these mutations has provided evidence for the involvement of the ribosome in the process of protein localization. The structural genes for the porin proteins, 1a and 1b, are regulated at the transcriptional level by the ompB locus. This has permitted us to extend our studies on outer membrane protein localization to protein 1. With this genetic system, it should be possible to determine if E coli employs more than a single mechanism for the export of proteins to the outer membrane.Keywords
This publication has 61 references indexed in Scilit:
- Mutations affecting localization of an Escherichia coli outer membrane protein, the bacteriophage λ receptorJournal of Molecular Biology, 1980
- Sequence analysis of mutations that prevent export of λ receptor, an Escherichia coli outer membrane proteinNature, 1980
- The Assembly of Cell MembranesScientific American, 1979
- Processing in vitro of Precursor Periplasmic Proteins from Escherichia coliEuropean Journal of Biochemistry, 1978
- Dominant constitutive mutations in malT, the positive regulator gene of the maltose regulon in Escherichia coliJournal of Molecular Biology, 1978
- The Outer Membrane Proteins of Gram-Negative Bacteria: Biosynthesis, Assembly, and FunctionsAnnual Review of Biochemistry, 1978
- The use of thin acrylamide gels for DNA sequencingFEBS Letters, 1978
- Studies on bacteriophage fd DNAJournal of Molecular Biology, 1977
- Transposition and fusion of the lac genes to selected promoters in Escherichia coli using bacteriophage lambda and MuJournal of Molecular Biology, 1976
- Transfer of proteins across membranes. I. Presence of proteolytically processed and unprocessed nascent immunoglobulin light chains on membrane-bound ribosomes of murine myeloma.The Journal of cell biology, 1975