Chapter 3 The Use of Genetic Techniques to Analyze Protein Export in Escherichia coli Chapter uri icon


  • This chapter discusses the use of genetic techniques to analyze protein export in Escherichia coli (E. coli), which lacks any kind of internal, membrane-bounded organelles. The task of localizing proteins to their correct, final destination is somewhat simpler than that faced by a eukaryotic cell. Various proteins are exported to one of three extracytoplasmic compartments: (1) the cytoplasmic or inner membrane includes a number of proteins involved in nutrient transport, energy metabolism, chemotaxis, lipid biosynthesis, and other processes; (2) the outer membrane contains relatively fewer proteins, but certain of these constitute major cellular proteins. Many outer membrane proteins function in the transport of various hydrophilic substances across this barrier by either active or passive mechanisms and were initially identified by their properties as receptors for different bacteriophages and/or colicins; (3) the periplasm, an aqueous space bounded by the cytoplasmic and outer membranes, contains two general classes of proteins. A classic genetic approach to the understanding of protein localization in E. coli calls for the isolation of mutants unable to export one or more proteins to their proper extracytoplasmic compartment. An analysis of such mutants could reveal (1) the properties inherent to extracytoplasmic proteins that facilitate correct localization, (2) the domains of these proteins within which such specific export signals are located, and (3) the nature of the cellular protein export machinery, if indeed any such specialized apparatus exists. 1985, Elsevier Inc. All rights reserved.

author list (cited authors)

  • Bankaitis, V. A., Ryan, J. P., Rasmussen, B. A., & Bassford, P. J.

citation count

  • 46

complete list of authors

  • Bankaitis, Vytas A||Ryan, J Patrick||Rasmussen, Beth A||Bassford, Philip J

Book Title

  • Membrane Protein Biosynthesis and Turnover

publication date

  • January 1985