The Tol Proteins of Escherichia Coli and Their Involvement in the Translocation of Group A Colicins

Biochimie. May-Jun 2002;84(5-6):391-7. doi: 10.1016/s0300-9084(02)01419-0.


The Tol proteins are involved in outer membrane stability of Gram-negative bacteria. The TolQRA proteins form a complex in the inner membrane while TolB and Pal interact near the outer membrane. These two complexes are transiently connected by an energy-dependent interaction between Pal and TolA. The Tol proteins have been parasitized by group A colicins for their translocation through the cell envelope. Recent advances in the structure and energetics of the Tol system, as well as the interactions between the N-terminal translocation domain of colicins and the Tol proteins are presented.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Colicins / metabolism*
  • Escherichia coli / metabolism
  • Escherichia coli Proteins / metabolism*
  • Membrane Proteins / metabolism*
  • Protein Transport / physiology


  • Colicins
  • Escherichia coli Proteins
  • Membrane Proteins
  • tolA protein, E coli
  • tolQ protein, E coli
  • tolR protein, E coli