1887

Abstract

Summary: The regulatory operon is involved in sucrose induction of the levansucrase gene by an antitermination mechanism. In the presence of sucrose, the activated SacY antiterminator protein stabilizes the secondary structure of a ribonucleic antiterminator sequence (RAT) located in the leader region of the transcript, and overlapping a rho-independent transcription terminator. Formation of the SacY-RAT complex prevents alternative formation of the terminator, allowing transcription of the downstream sequences. In the absence of sucrose, inhibition of SacY activity by SacX leads to termination of transcription. Expression of is also sucrose-inducible. This induction was previously shown to be mediated by SacY itself and/or SacT, another antiterminator involved in induction of genes belonging to a distinct sucrose pathway. These antiterminators are not activated at the same concentration of sucrose. We show here that induction occurs through activation of either SacY or SacT antiterminators, at their respective sucrose activation concentration. This result demonstrates a link between SacY- and SacT-mediated metabolic pathways. In addition, the leader region carries a RAT-like sequence, which however does not appear to overlap any apparent rho-independent transcription terminator. Site-directed mutagenesis experiments on this RAT-like sequence demonstrated its involvement in sucrose induction. Deletions generated in the leader region showed that a palindrome, located 100 nt downstream from the RAT-like sequence, also acts as a -acting element. Computer analysis of the leader RNA suggested that formation of the secondary structure of the RAT-like sequence and the palindrome could be mutually exclusive.

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1995-11-01
2021-10-16
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References

  1. Arnaud M., Vary P., Zagorec M., Klier A., Débarbouillé M., Postma P., Rapoport G. 1992; Regulation of the sacPA operon of Bacillus subtilis: identification of phosphotransferase system components involved in SacT activity.. J Bacteriol 174:3161–3170
    [Google Scholar]
  2. Aymerich S., Steinmetz M. 1992; Specificitv determinants and structural features in the RN A target of the bacterial anti-terminator proteins of the BglG/SacY family.. Proc Natl AcadSci USA 8910410–10414
    [Google Scholar]
  3. Bardowski J., Ehrlich S.D., Chopin A. 1994; BglR protein, which belongs to the BglGfamilv of transcriptional antiterminators, is involved in βglucoside utilization in Lactococcus lactis.. j Bacteriol 176:5681–5685
    [Google Scholar]
  4. Crutz A.-M., Steinmetz M. 1992; Transcription of the B. subtilis sacXYoperon, encoding regulators of sucrose metabolism, is both sucrose inducible and controlled by the DegS/DegU signalling system.. J Bacteriol 174:6087–6095
    [Google Scholar]
  5. Crutz A.-M., Steinmetz M., Aymerich S., Richter R., Le Coq D. 1990; Induction of levansucrase in Bacillus subtilis-.an anti-termination mechanism negativelv controlled by the phosphotransferase system.. J Bacteriol 172:1043–1050
    [Google Scholar]
  6. Das A., Court D., Adhya S. 1976; Isolation and characterization of conditional lethal mutants of Escherichia colidefective in transcription termination factor rho.. Proc Natl Acad Sci USA 731959–1963
    [Google Scholar]
  7. Débarbouillé M., Arnaud M., Fouet A., Klier A., Rapoport G. 1990; The sacTgene regulating the sacPAoperon in Bacillus subtilisshares strong homologies with transcriptional antiterminators.. J Bacteriol 172:3966–3973
    [Google Scholar]
  8. Genetics Computer Group 1994 Program Manual for the GCG Package, version 8, August 1994. Madison, Wisconsin: Genetics Computer Group;
    [Google Scholar]
  9. Kunkel T.A., Roberts J.D., Zakour A.R. 1987; Rapid and efficient site-specific mutagenesis without phenotypic selection.. Methods Enzymol 154:367–382
    [Google Scholar]
  10. Le Coq D., Lindner C., Krüger S., Steinmetz M., Stülke J. 1995; New β-glucoside(bgl)genes in Bacillus subtilis: the bglPgene product has both transport and regulatory functions similar to those of BglF, its Escherichia colihomolog.. J Bacteriol 177:1527–1535
    [Google Scholar]
  11. Miller J.H. 1972 Experiments in Molecular Genetics. Cold Spring Harbor, NY: Cold Spring Harbor Laboratory;
    [Google Scholar]
  12. Perkins J.B., Youngman P.J. 1986; Construction and properties of Tn917-/ac,a transposon derivative that mediates transcriptional gene fusions in Bacillus subtilis.. Proc Sail Acad Sci USA 83140–144
    [Google Scholar]
  13. Piggot P.J., Curtis C.A.M. 1987; Analvsis of the regulation of gene expression during Bacillus subtilissporulation bv manipulation of the copv number of spo-lacZ fusions.. J Bacteriol 169:1260–1266
    [Google Scholar]
  14. Podvin L., Steinmetz M. 1992; A degU-containing SPβ prophage complements superactivator mutations affecting the degSUoperon.. Rpr Microbiol 143:559–567
    [Google Scholar]
  15. Quirk P. G., Dunkley E. A., Lee P., Krulwich T. A. 1993; Identification of a putative Bacillus subtilis rhogene.. J Bacteriol 175:647–654
    [Google Scholar]
  16. Sanger F., Nicklen S., Coulson A.R. 1977; DNA sequencing with chain-termination inhibitors.. Proc Natl Acad Sci USA 745463–5467
    [Google Scholar]
  17. Shimotsu H., Henner D.J. 1986; C Construction of a single copv integration vector and its use in analvsis of regulation of the trpoperon of Bacillus subtilis.. Gene 43:84–94
    [Google Scholar]
  18. Steinmetz M. 1993; Carbohvdrate catabolism: enzymes, pathways and evolution.. In Bacillus subtilis and other Gram-Positive Bacteria: Biochemistry, Physiology and Molecular Genetics pp. 157–170 Edited by Sonenshein A.L., Hoch J.A., Losick R. Washington, DC: American Societv for Microbiology;
    [Google Scholar]
  19. Steinmetz M., Aymerich S. 1990; Bacillus subtilis sac degconstellation: how and why?. In Genetics and Biotechnology of Bacilli 3 pp. 303–311 Edited by Zukowski M.M., Ganesan A.T., Hoch J.A. New York: Academic Press;
    [Google Scholar]
  20. Steinmetz M., Le Coq D., Aymerich S. 1989; Induction by sucrose of saccharolytic enzymes in Bacillus subtilis:evidence for two partiallv interchangeable pathways.. J Bacteriol 171:1519–1523
    [Google Scholar]
  21. Vieira J., Messing J. 1982; The pUC plasmids, an M13mp7- derived svstem for insertion mutagenesis and sequencing with synthetic universal primers.. Gene 19:259–268
    [Google Scholar]
  22. Zukowski M.M., Miller L., Cogswell P., Chen K., Aymerich S., Steinmetz M. 1990; Nucleotide sequence of the sacSlocus of Bacillus subtilisreveals the presence of two regulatory genes.. Gene 90:153–155
    [Google Scholar]
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