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. 1990 Apr;172(4):1688–1693. doi: 10.1128/jb.172.4.1688-1693.1990

Topology of the Escherichia coli uhpT sugar-phosphate transporter analyzed by using TnphoA fusions.

A D Lloyd 1, R J Kadner 1
PMCID: PMC208657  PMID: 2156798

Abstract

The Escherichia coli uhpT protein catalyzes the active transport of sugar-phosphates by an obligatory exchange mechanism. To examine its transmembrane topology, we isolated a collection of uhpT-phoA fusions encoding hybrid proteins of different lengths from the N terminus of UhpT fused to alkaline phosphatase by using transposon TnphoA. These fusions displayed different levels of alkaline phosphatase activity, although comparable levels of full-length UhpT-PhoA proteins were produced in maxicells of both high- and low-activity fusions. The full-length protein species were unstable and were degraded to the size of the alkaline phosphatase moiety in the case of a high-activity fusion or to small fragments in the case of a low-activity fusion. The enzyme activity present in low-activity fusions appeared to result from export of a small proportion of the fusion proteins to the periplasmic space. Although fusions were not obtained in all predicted extramembranous loops, the deduced topology of UhpT was consistent with a model of 12 membrane-spanning regions oriented with the amino and carboxyl termini in the cytoplasm.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Ambudkar S. V., Larson T. J., Maloney P. C. Reconstitution of sugar phosphate transport systems of Escherichia coli. J Biol Chem. 1986 Jul 15;261(20):9083–9086. [PubMed] [Google Scholar]
  2. Boyd D., Manoil C., Beckwith J. Determinants of membrane protein topology. Proc Natl Acad Sci U S A. 1987 Dec;84(23):8525–8529. doi: 10.1073/pnas.84.23.8525. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Brickman E., Beckwith J. Analysis of the regulation of Escherichia coli alkaline phosphatase synthesis using deletions and phi80 transducing phages. J Mol Biol. 1975 Aug 5;96(2):307–316. doi: 10.1016/0022-2836(75)90350-2. [DOI] [PubMed] [Google Scholar]
  4. Carrasco N., Herzlinger D., Mitchell R., DeChiara S., Danho W., Gabriel T. F., Kaback H. R. Intramolecular dislocation of the COOH terminus of the lac carrier protein in reconstituted proteoliposomes. Proc Natl Acad Sci U S A. 1984 Aug;81(15):4672–4676. doi: 10.1073/pnas.81.15.4672. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Chun S. Y., Parkinson J. S. Bacterial motility: membrane topology of the Escherichia coli MotB protein. Science. 1988 Jan 15;239(4837):276–278. doi: 10.1126/science.2447650. [DOI] [PubMed] [Google Scholar]
  6. Eiglmeier K., Boos W., Cole S. T. Nucleotide sequence and transcriptional startpoint of the glpT gene of Escherichia coli: extensive sequence homology of the glycerol-3-phosphate transport protein with components of the hexose-6-phosphate transport system. Mol Microbiol. 1987 Nov;1(3):251–258. doi: 10.1111/j.1365-2958.1987.tb01931.x. [DOI] [PubMed] [Google Scholar]
  7. Eisenberg D., Schwarz E., Komaromy M., Wall R. Analysis of membrane and surface protein sequences with the hydrophobic moment plot. J Mol Biol. 1984 Oct 15;179(1):125–142. doi: 10.1016/0022-2836(84)90309-7. [DOI] [PubMed] [Google Scholar]
  8. Eisenberg D. Three-dimensional structure of membrane and surface proteins. Annu Rev Biochem. 1984;53:595–623. doi: 10.1146/annurev.bi.53.070184.003115. [DOI] [PubMed] [Google Scholar]
  9. Friedrich M. J., Kadner R. J. Nucleotide sequence of the uhp region of Escherichia coli. J Bacteriol. 1987 Aug;169(8):3556–3563. doi: 10.1128/jb.169.8.3556-3563.1987. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Goldrick D., Yu G. Q., Jiang S. Q., Hong J. S. Nucleotide sequence and transcription start point of the phosphoglycerate transporter gene of Salmonella typhimurium. J Bacteriol. 1988 Aug;170(8):3421–3426. doi: 10.1128/jb.170.8.3421-3426.1988. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Gött P., Boos W. The transmembrane topology of the sn-glycerol-3-phosphate permease of Escherichia coli analysed by phoA and lacZ protein fusions. Mol Microbiol. 1988 Sep;2(5):655–663. doi: 10.1111/j.1365-2958.1988.tb00074.x. [DOI] [PubMed] [Google Scholar]
  12. Heijne G. The distribution of positively charged residues in bacterial inner membrane proteins correlates with the trans-membrane topology. EMBO J. 1986 Nov;5(11):3021–3027. doi: 10.1002/j.1460-2075.1986.tb04601.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Ito K., Bassford P. J., Jr, Beckwith J. Protein localization in E. coli: is there a common step in the secretion of periplasmic and outer-membrane proteins? Cell. 1981 Jun;24(3):707–717. doi: 10.1016/0092-8674(81)90097-0. [DOI] [PubMed] [Google Scholar]
  14. Kaback H. R. Molecular biology of active transport: from membrane to molecule to mechanism. Harvey Lect. 1987;83:77–105. [PubMed] [Google Scholar]
  15. Kyte J., Doolittle R. F. A simple method for displaying the hydropathic character of a protein. J Mol Biol. 1982 May 5;157(1):105–132. doi: 10.1016/0022-2836(82)90515-0. [DOI] [PubMed] [Google Scholar]
  16. Lugtenberg B., Meijers J., Peters R., van der Hoek P., van Alphen L. Electrophoretic resolution of the "major outer membrane protein" of Escherichia coli K12 into four bands. FEBS Lett. 1975 Oct 15;58(1):254–258. doi: 10.1016/0014-5793(75)80272-9. [DOI] [PubMed] [Google Scholar]
  17. Maiden M. C., Davis E. O., Baldwin S. A., Moore D. C., Henderson P. J. Mammalian and bacterial sugar transport proteins are homologous. Nature. 1987 Feb 12;325(6105):641–643. doi: 10.1038/325641a0. [DOI] [PubMed] [Google Scholar]
  18. Manoil C., Beckwith J. A genetic approach to analyzing membrane protein topology. Science. 1986 Sep 26;233(4771):1403–1408. doi: 10.1126/science.3529391. [DOI] [PubMed] [Google Scholar]
  19. Manoil C., Beckwith J. TnphoA: a transposon probe for protein export signals. Proc Natl Acad Sci U S A. 1985 Dec;82(23):8129–8133. doi: 10.1073/pnas.82.23.8129. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Maurer P., Lessmann D., Kurz G. D-Glucose-6-phosphate dehydrogenases from Pseudomonas fluorescens. Methods Enzymol. 1982;89(Pt 500):261–270. doi: 10.1016/s0076-6879(82)89047-2. [DOI] [PubMed] [Google Scholar]
  21. Neu H. C., Heppel L. A. 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] [Google Scholar]
  22. San Millan J. L., Boyd D., Dalbey R., Wickner W., Beckwith J. Use of phoA fusions to study the topology of the Escherichia coli inner membrane protein leader peptidase. J Bacteriol. 1989 Oct;171(10):5536–5541. doi: 10.1128/jb.171.10.5536-5541.1989. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. Sancar A., Hack A. M., Rupp W. D. Simple method for identification of plasmid-coded proteins. J Bacteriol. 1979 Jan;137(1):692–693. doi: 10.1128/jb.137.1.692-693.1979. [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. Sonna L. A., Ambudkar S. V., Maloney P. C. The mechanism of glucose 6-phosphate transport by Escherichia coli. J Biol Chem. 1988 May 15;263(14):6625–6630. [PubMed] [Google Scholar]
  25. Towbin H., Staehelin T., Gordon J. Electrophoretic transfer of proteins from polyacrylamide gels to nitrocellulose sheets: procedure and some applications. Proc Natl Acad Sci U S A. 1979 Sep;76(9):4350–4354. doi: 10.1073/pnas.76.9.4350. [DOI] [PMC free article] [PubMed] [Google Scholar]
  26. Weston L. A., Kadner R. J. Role of uhp genes in expression of the Escherichia coli sugar-phosphate transport system. J Bacteriol. 1988 Aug;170(8):3375–3383. doi: 10.1128/jb.170.8.3375-3383.1988. [DOI] [PMC free article] [PubMed] [Google Scholar]

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