Role of uhp genes in expression of the Escherichia coli sugar-phosphate transport system (original) (raw)

Abstract

The uhpABCT locus of Escherichia coli is responsible for expression of the sugar-phosphate transport system and its induction by external glucose 6-phosphate. Expression of uhpT-lacZ fusions depended on the function of uhpA, uhpB, and uhpC but not of uhpT. A plasmid carrying only uhpT conferred transport activity in a host strain deleted for the uhp region. Thus, uhpT encodes the polypeptide required for transport function, and the other three uhp genes regulate uhpT transcription. The presence of uhpA at elevated copy number resulted in a substantial increase in uhpT expression. This elevated expression was only about 50% of the level seen in induced haploid cells, and no further increase occurred after addition of inducer. Activation by multicopy uhpA was not affected by the status of uhpC but was decreased in the absence of uhpB, suggesting a role for UhpB in directly activating UhpA. Transcription of uhpA, monitored by expression of a uhpA-lacZ fusion, was not affected by either inducer or the presence of the wild-type uhpA allele. The presence of multiple copies of the uhpT promoter region reduced uhpT expression in strains with uhpA in single copy number but not in those with multiple copies, consistent with competition for the activator. Amino acid sequence comparisons showed that UhpA was homologous to a family of bacterial regulatory proteins, some of which act as transcriptional activators (OmpR, PhoB, NtrC, and DctD). The C-terminal portion of UhpB displayed matches to the corresponding portions of another family of proteins (EnvZ, PhoMR, NtrB, and DctB) that participate in regulation of gene expression in response to environmental factors.

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Selected References

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  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. Bachmann B. J. Linkage map of Escherichia coli K-12, edition 7. Microbiol Rev. 1983 Jun;47(2):180–230. doi: 10.1128/mr.47.2.180-230.1983. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Dietz G. W., Heppel L. A. Studies on the uptake of hexose phosphates. II. The induction of the glucose 6-phosphate transport system by exogenous but not by endogenously formed glucose 6-phosphate. J Biol Chem. 1971 May 10;246(9):2885–2890. [PubMed] [Google Scholar]
  4. Drummond M., Whitty P., Wootton J. Sequence and domain relationships of ntrC and nifA from Klebsiella pneumoniae: homologies to other regulatory proteins. EMBO J. 1986 Feb;5(2):441–447. doi: 10.1002/j.1460-2075.1986.tb04230.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Drury L. S., Buxton R. S. DNA sequence analysis of the dye gene of Escherichia coli reveals amino acid homology between the dye and OmpR proteins. J Biol Chem. 1985 Apr 10;260(7):4236–4242. [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. 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]
  8. Guan C. D., Wanner B., Inouye H. Analysis of regulation of phoB expression using a phoB-cat fusion. J Bacteriol. 1983 Nov;156(2):710–717. doi: 10.1128/jb.156.2.710-717.1983. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Hall M. N., Silhavy T. J. Genetic analysis of the ompB locus in Escherichia coli K-12. J Mol Biol. 1981 Sep 5;151(1):1–15. doi: 10.1016/0022-2836(81)90218-7. [DOI] [PubMed] [Google Scholar]
  10. Kadner R. J., Winkler H. H. Isolation and characterization of mutations affecting the transport of hexose phosphates in Escherichia coli. J Bacteriol. 1973 Feb;113(2):895–900. doi: 10.1128/jb.113.2.895-900.1973. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Komeda Y., Iino T. Regulation of expression of the flagellin gene (hag) in Escherichia coli K-12: analysis of hag-lac gene fusions. J Bacteriol. 1979 Sep;139(3):721–729. doi: 10.1128/jb.139.3.721-729.1979. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Larson T. J., Schumacher G., Boos W. Identification of the glpT-encoded sn-glycerol-3-phosphate permease of Escherichia coli, an oligomeric integral membrane protein. J Bacteriol. 1982 Dec;152(3):1008–1021. doi: 10.1128/jb.152.3.1008-1021.1982. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Lipman D. J., Pearson W. R. Rapid and sensitive protein similarity searches. Science. 1985 Mar 22;227(4693):1435–1441. doi: 10.1126/science.2983426. [DOI] [PubMed] [Google Scholar]
  14. Makino K., Shinagawa H., Amemura M., Nakata A. Nucleotide sequence of the phoB gene, the positive regulatory gene for the phosphate regulon of Escherichia coli K-12. J Mol Biol. 1986 Jul 5;190(1):37–44. doi: 10.1016/0022-2836(86)90073-2. [DOI] [PubMed] [Google Scholar]
  15. Matsumura P., Rydel J. J., Linzmeier R., Vacante D. Overexpression and sequence of the Escherichia coli cheY gene and biochemical activities of the CheY protein. J Bacteriol. 1984 Oct;160(1):36–41. doi: 10.1128/jb.160.1.36-41.1984. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Ninfa A. J., Magasanik B. Covalent modification of the glnG product, NRI, by the glnL product, NRII, regulates the transcription of the glnALG operon in Escherichia coli. Proc Natl Acad Sci U S A. 1986 Aug;83(16):5909–5913. doi: 10.1073/pnas.83.16.5909. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Nixon B. T., Ronson C. W., Ausubel F. M. Two-component regulatory systems responsive to environmental stimuli share strongly conserved domains with the nitrogen assimilation regulatory genes ntrB and ntrC. Proc Natl Acad Sci U S A. 1986 Oct;83(20):7850–7854. doi: 10.1073/pnas.83.20.7850. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Rogowsky P. M., Close T. J., Chimera J. A., Shaw J. J., Kado C. I. Regulation of the vir genes of Agrobacterium tumefaciens plasmid pTiC58. J Bacteriol. 1987 Nov;169(11):5101–5112. doi: 10.1128/jb.169.11.5101-5112.1987. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Ronson C. W., Astwood P. M., Nixon B. T., Ausubel F. M. Deduced products of C4-dicarboxylate transport regulatory genes of Rhizobium leguminosarum are homologous to nitrogen regulatory gene products. Nucleic Acids Res. 1987 Oct 12;15(19):7921–7934. doi: 10.1093/nar/15.19.7921. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Saier M. H., Jr, Wentzel D. L., Feucht B. U., Judice J. J. A transport system for phosphoenolpyruvate, 2-phosphoglycerate, and 3-phosphoglycerate in Salmonella typhimurium. J Biol Chem. 1975 Jul 10;250(13):5089–5096. [PubMed] [Google Scholar]
  21. Shapira S. K., Chou J., Richaud F. V., Casadaban M. J. New versatile plasmid vectors for expression of hybrid proteins coded by a cloned gene fused to lacZ gene sequences encoding an enzymatically active carboxy-terminal portion of beta-galactosidase. Gene. 1983 Nov;25(1):71–82. doi: 10.1016/0378-1119(83)90169-5. [DOI] [PubMed] [Google Scholar]
  22. Shattuck-Eidens D. M., Kadner R. J. Exogenous induction of the Escherichia coli hexose phosphate transport system defined by uhp-lac operon fusions. J Bacteriol. 1981 Oct;148(1):203–209. doi: 10.1128/jb.148.1.203-209.1981. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. Shattuck-Eidens D. M., Kadner R. J. Molecular cloning of the uhp region and evidence for a positive activator for expression of the hexose phosphate transport system of Escherichia coli. J Bacteriol. 1983 Sep;155(3):1062–1070. doi: 10.1128/jb.155.3.1062-1070.1983. [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. Weston L. A., Kadner R. J. Identification of uhp polypeptides and evidence for their role in exogenous induction of the sugar phosphate transport system of Escherichia coli K-12. J Bacteriol. 1987 Aug;169(8):3546–3555. doi: 10.1128/jb.169.8.3546-3555.1987. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Winans S. C., Ebert P. R., Stachel S. E., Gordon M. P., Nester E. W. A gene essential for Agrobacterium virulence is homologous to a family of positive regulatory loci. Proc Natl Acad Sci U S A. 1986 Nov;83(21):8278–8282. doi: 10.1073/pnas.83.21.8278. [DOI] [PMC free article] [PubMed] [Google Scholar]
  26. Winkler H. H. Compartmentation in the induction of the hexose-6-phosphate transport system of Escherichia coli. J Bacteriol. 1970 Feb;101(2):470–475. doi: 10.1128/jb.101.2.470-475.1970. [DOI] [PMC free article] [PubMed] [Google Scholar]
  27. Yu G. Q., Hong J. S. Identification and nucleotide sequence of the activator gene of the externally induced phosphoglycerate transport system of Salmonella typhimurium. Gene. 1986;45(1):51–57. doi: 10.1016/0378-1119(86)90131-9. [DOI] [PubMed] [Google Scholar]