Logo of pnasPNASInfo for AuthorsSubscriptionsAboutThis Article
Proc Natl Acad Sci U S A. 1991 Jul 15; 88(14): 5939–5943.

TolA: a membrane protein involved in colicin uptake contains an extended helical region.


The group A colicins and the DNA of many single-stranded filamentous bacteriophage are able to use combinations of the Tol proteins to gain entrance into or across the membrane of Escherichia coli. The TolA protein is a 421-amino acid residue integral membrane protein composed of three domains. Domain I, consisting of the amino-terminal 47 amino acids, contains a 21-residue hydrophobic segment that anchors the protein in the inner membrane. The remaining 374 amino acids, containing the other two domains, reside in the periplasmic space. Domain III, consisting of the carboxyl-terminal 120 residues, is considered to be the functional domain based on the location of the tolA592 deletion mutation. The internal 262 amino acids comprise domain II, which connects domains I and III together via short regions of polyglycine. It contains a large number of 3- to 5-residue polyalanine stretches, many of which have a repeat of the sequence Lys-Ala-Ala-Ala-(Glu/Asp). Circular dichroism analysis of different portions of TolA show domain II to be predominantly alpha-helical in structure while domain III contains approximately 10% helical structure.

Full text

Full text is available as a scanned copy of the original print version. Get a printable copy (PDF file) of the complete article (1.1M), or click on a page image below to browse page by page. Links to PubMed are also available for Selected References.

Images in this article

Click on the image to see a larger version.

Selected References

These references are in PubMed. This may not be the complete list of references from this article.
  • Hill C, Holland IB. Genetic basis of colicin E susceptibility in Escherichia coli. I. Isolation and properties of refractory mutants and the preliminary mapping of their mutations. J Bacteriol. 1967 Sep;94(3):677–686. [PMC free article] [PubMed]
  • Nomura M, Witten C. Interaction of colicins with bacterial cells. 3. Colicin-tolerant mutations in Escherichia coli. J Bacteriol. 1967 Oct;94(4):1093–1111. [PMC free article] [PubMed]
  • Nagel de Zwaig R, Luria SE. Genetics and physiology of colicin-tolerant mutants of Escherichia coli. J Bacteriol. 1967 Oct;94(4):1112–1123. [PMC free article] [PubMed]
  • Sun TP, Webster RE. fii, a bacterial locus required for filamentous phage infection and its relation to colicin-tolerant tolA and tolB. J Bacteriol. 1986 Jan;165(1):107–115. [PMC free article] [PubMed]
  • Sun TP, Webster RE. Nucleotide sequence of a gene cluster involved in entry of E colicins and single-stranded DNA of infecting filamentous bacteriophages into Escherichia coli. J Bacteriol. 1987 Jun;169(6):2667–2674. [PMC free article] [PubMed]
  • Levengood SK, Webster RE. Nucleotide sequences of the tolA and tolB genes and localization of their products, components of a multistep translocation system in Escherichia coli. J Bacteriol. 1989 Dec;171(12):6600–6609. [PMC free article] [PubMed]
  • Marqusee S, Baldwin RL. Helix stabilization by Glu-...Lys+ salt bridges in short peptides of de novo design. Proc Natl Acad Sci U S A. 1987 Dec;84(24):8898–8902. [PMC free article] [PubMed]
  • Studier FW, Moffatt BA. Use of bacteriophage T7 RNA polymerase to direct selective high-level expression of cloned genes. J Mol Biol. 1986 May 5;189(1):113–130. [PubMed]
  • Rosenberg AH, Lade BN, Chui DS, Lin SW, Dunn JJ, Studier FW. Vectors for selective expression of cloned DNAs by T7 RNA polymerase. Gene. 1987;56(1):125–135. [PubMed]
  • Laemmli UK. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature. 1970 Aug 15;227(5259):680–685. [PubMed]
  • Neu HC, Heppel LA. The release of enzymes from Escherichia coli by osmotic shock and during the formation of spheroplasts. J Biol Chem. 1965 Sep;240(9):3685–3692. [PubMed]
  • Yang JT, Wu CS, Martinez HM. Calculation of protein conformation from circular dichroism. Methods Enzymol. 1986;130:208–269. [PubMed]
  • Nozaki Y. Determination of the concentration of protein by dry weight--a comparison with spectrophotometric methods. Arch Biochem Biophys. 1986 Sep;249(2):437–446. [PubMed]
  • Ozols J. Amino acid analysis. Methods Enzymol. 1990;182:587–601. [PubMed]
  • Greenfield N, Fasman GD. Computed circular dichroism spectra for the evaluation of protein conformation. Biochemistry. 1969 Oct;8(10):4108–4116. [PubMed]
  • Chen YH, Yang JT. A new approach to the calculation of secondary structures of globular proteins by optical rotatory dispersion and circular dichroism. Biochem Biophys Res Commun. 1971 Sep 17;44(6):1285–1291. [PubMed]
  • Chen YH, Yang JT, Chau KH. Determination of the helix and beta form of proteins in aqueous solution by circular dichroism. Biochemistry. 1974 Jul 30;13(16):3350–3359. [PubMed]
  • Chou PY, Fasman GD. Empirical predictions of protein conformation. Annu Rev Biochem. 1978;47:251–276. [PubMed]
  • Garnier J, Osguthorpe DJ, Robson B. Analysis of the accuracy and implications of simple methods for predicting the secondary structure of globular proteins. J Mol Biol. 1978 Mar 25;120(1):97–120. [PubMed]
  • Chang CT, Wu CS, Yang JT. Circular dichroic analysis of protein conformation: inclusion of the beta-turns. Anal Biochem. 1978 Nov;91(1):13–31. [PubMed]
  • Marqusee S, Robbins VH, Baldwin RL. Unusually stable helix formation in short alanine-based peptides. Proc Natl Acad Sci U S A. 1989 Jul;86(14):5286–5290. [PMC free article] [PubMed]
  • Sundaralingam M, Sekharudu YC, Yathindra N, Ravichandran V. Ion pairs in alpha helices. Proteins. 1987;2(1):64–71. [PubMed]
  • Merutka G, Stellwagen E. Positional independence and additivity of amino acid replacements on helix stability in monomeric peptides. Biochemistry. 1990 Jan 30;29(4):894–898. [PubMed]
  • Bayer ME. Areas of adhesion between wall and membrane of Escherichia coli. J Gen Microbiol. 1968 Oct;53(3):395–404. [PubMed]
  • Kellenberger E. The 'Bayer bridges' confronted with results from improved electron microscopy methods. Mol Microbiol. 1990 May;4(5):697–705. [PubMed]

Articles from Proceedings of the National Academy of Sciences of the United States of America are provided here courtesy of National Academy of Sciences


Save items

Related citations in PubMed

See reviews...See all...

Cited by other articles in PMC

See all...


  • Gene
    Gene records that cite the current articles. Citations in Gene are added manually by NCBI or imported from outside public resources.
  • GEO Profiles
    GEO Profiles
    Gene Expression Omnibus (GEO) Profiles of molecular abundance data. The current articles are references on the Gene record associated with the GEO profile.
  • MedGen
    Related information in MedGen
  • Protein
    Protein translation features of primary database (GenBank) nucleotide records reported in the current articles as well as Reference Sequences (RefSeqs) that include the articles as references.
  • PubMed
    PubMed citations for these articles
  • Substance
    PubChem chemical substance records that cite the current articles. These references are taken from those provided on submitted PubChem chemical substance records.

Recent Activity

Your browsing activity is empty.

Activity recording is turned off.

Turn recording back on

See more...