The tol gene products and the import of macromolecules into Escherichia coli.
Genetic studies have identified a number of genes whose products appear to be required for the transport of the group A colicins and the single-stranded DNA of certain filamentous bacteriophages into Escherichia coli. Mutations in these genes allow normal binding of the colicins to their outer-membrane receptors and of the bacteriophage of the tip of specific conjugative pili, but do not allow translocation of the macromolecules to their target. These mutations have been designed 'tolerant' (tol) mutations and the protein products specified by these genes appear to comprise part of a transport system known as the Tol import system. Some of these genes have been isolated, sequenced and their protein products localized to the membranes or periplasm of E. coli. Information is also available regarding the domains of the colicins or phage proteins which interact with the Tol proteins. A preliminary model of the location and possible interactions of the Tol proteins is presented.
Department of Biochemistry, Duke University Medical Center, Durham, North Carolina 27710.
R E
RE
Webster
D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001692:Biological Transport; D002352:Carrier Proteins; D003087:Colicins / Q000378:metabolism*; D003090:Coliphages / Q000378:metabolism*; D004277:DNA, Single-Stranded / Q000378:metabolism; D004279:DNA, Viral / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D029968:Escherichia coli Proteins; D010861:Fimbriae, Bacterial / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D008565:Membrane Proteins / Q000378:metabolism*; D033903:Periplasmic Proteins; D011956:Receptors, Cell Surface; D011971:Receptors, Immunologic / Q000378:metabolism; D011991:Receptors, Virus / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism
D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D002352:Carrier Proteins; D003087:Colicins; D004277:DNA, Single-Stranded; D004279:DNA, Viral; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D033903:Periplasmic Proteins; D011956:Receptors, Cell Surface; D011971:Receptors, Immunologic; D011991:Receptors, Virus; D011993:Recombinant Fusion Proteins; C028593:colicin receptor, E coli; C062093:tolA protein, E coli; C062094:tolB protein, E coli; C060792:tolQ protein, E coli; C060794:tolR protein, E coli