Bacterial Protein Export

  • Stuart W. Shales


Consideration of protein export by bacteria is of major importance to many research institutions and industrial organisations currently involved in biotechnology. Bacteria (in particular, Escherichia coli), are used as hosts for the biosynthesis of proteins. Genes encoding these products may have been introduced into the cells by the elegant and powerful techniques of genetic engineering. It would be highly desirable if the bacterial host could export such proteins into the extracellular medium, namely the fermentation broth. There are two principal reasons for this: first, downstream processing (i.e. product separation, concentration and purification) would be simplified and, consequently, less expensive, and second, export would overcome the problem of product degradation by intracellular protease enzymes. Both of these factors could well influence the financial viability of a process and are, therefore, of significant concern to the biotechnologist. What is desired and what can be achieved are, however, entirely different and this is, in part, questioning the continuing use of existing bacterial strains in recombinant DNA technology. There are other factors relating to host suitability which need to be taken into account — for example, genetic instability, glycosylation, pyrogen and toxin production; these will be discussed later.


Outer Membrane Protein Secretion Cytoplasmic Membrane Mature Protein Leader Sequence 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

Reference and Bibliography

  1. 1.
    Breton, A. M., Micaud, J. M., Younes, G. and Guespin-Michel, J. F. (1984). Myxococcus xantus, a Gram-negative non-pathogenic bacterium, that secretes proteins into the extracellular growth medium, is a potential cloning host for excreted protein production. Proceedings of the Third European Congress on Biotechnology, Munich, pp.441–446Google Scholar
  2. 2.
    Date, T. (1983). Demonstration by a novel genetic technique that leader peptidase is an essential enzyme of Escherichia coli. Journal of Bacteriology, 154, 76–83Google Scholar
  3. 3.
    Date, T. and Wickner, W. (1981). Isolation of the Escherichia coli leader peptidase gene and effects of leader peptidase overproduction in vivo. Proceedings of the National Academy of Sciences, USA, 78, 6106–6110CrossRefGoogle Scholar
  4. 4.
    Davies, B. D. and Tai, P. C. (1980). The mechanism of protein secretion across membranes. Nature, Lond., 283, 433–438CrossRefGoogle Scholar
  5. 5.
    Emerick, A. W., Bertolani, B. L., Ben-Bassat, A., White, T. J. and Konrad, M. W. (1984). Expression of a β-lactamase preproinsulin fusion protein in Escherichia coli. Biotechnology, 2, 165–168Google Scholar
  6. 6.
    Gilkes, N. R., Kilburn, D. G., Miller, R. C. Jr. and Warren, R. A. J. (1984). A mutant of Escherichia coli that leaks cellulase activity encoded by cloned cellulase genes from Cellulomonas fimi. Biotechnology, 2, 259–263Google Scholar
  7. 7.
    Gray, G. L., McKeown, J. A., Jones, A. J. S., Seeburg, P. H. and Heyneker, H. L. (1984). Pseudomonas aeruginosa secretes and correctly processes human growth hormone. Biotechnology, 2, 161–165CrossRefGoogle Scholar
  8. 8.
    Kingsman, S. M. and Kingsman, A. J. (1983). The production of interferon in bacteria and yeast. In Interferons: From Molecular Biology to Clinical Applications (D. C. Burke and A. G. Morris, Eds.). Symposium 35, published for the Society for General Microbiology by Cambridge University Press, pp.212–254Google Scholar
  9. 9.
    Michaelis, S. and Beckwith, J. (1982). Mechanisms of incorporation of cell envelope proteins in Escherichia coli. Annual Reviews of Microbiology, 36, 435–465CrossRefGoogle Scholar
  10. 10.
    Michaelis, S., Guarente, L. and Beckwith, J. (1983). In vitro construction and characterization of phoA-lacZ gene fusions in Escherichia coli. Journal of Bacteriology, 154, 356–365Google Scholar
  11. 11.
    Michaelis, S., Inouye, H., Oliver, D. and Beckwith, J. (1983). Mutations that alter the signal sequence of alkaline phosphatase in Escherichia coli. Journal of Bacteriology, 154, 366–374Google Scholar
  12. 12.
    Mosback, K., Birnbaum, S., Hardy, K., Davies, J. and Bulow, L. (1983). Formation of proinsulin by immobilized Bacillus subtilis. Nature, Lond., 302, 543–545CrossRefGoogle Scholar
  13. 13.
    Palade, G. E. (1975). Intracellular aspects of the process of protein synthesis. Science, 189, 347–358CrossRefGoogle Scholar
  14. 14.
    Silhavy, T. J., Benson, S. A. and Emr, S. D. (1983). Mechanisms of protein localization. Microbiological Reviews, 47, 313–344Google Scholar
  15. 15.
    Wickner, W. (1980). Assembly of proteins into membranes. Science, 210, 861–868CrossRefGoogle Scholar

Copyright information

© The Editor and the Contributors 1988

Authors and Affiliations

  • Stuart W. Shales

There are no affiliations available

Personalised recommendations