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Isomerization of a binary sigma–promoter DNA complex by transcription activators

Abstract

Multisubunit RNA polymerases are targets of sophisticated signal transduction pathways that link environmental or temporal cues to changes in gene expression. Here we show that the sigma 54 protein (σ54), responsible for promoter specific binding by bacterial RNA polymerase, undergoes a nucleotide hydrolysis dependent isomerization on DNA. Changes in protein structure are evident. The isomerization has all the known requirements of σ54-dependent transcription, including a dependence on enhancer binding activator proteins and occurs independently of the core RNA polymerase. We suggest that activator driven changes in σ54 conformation trigger the conversion of a transcriptionally silent RNA polymerase conformation to one able to interact productively with template DNA. Our results illustrate the types of changes that must occur for multisubunit complexes to manipulate DNA, and show that transcription activators can remodel key nucleoprotein structures to achieve direct activation of transcription.

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Figure 1: Binding of σ54 to heteroduplex DNA.
Figure 2: DNase I footprints of σ54 and supershifted DNA complexes.
Figure 3: Protease footprints of 32P end-labeled σ54.
Figure 4: Region I complements ΔIσ54 for supershifted complex formation.

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References

  1. Gross, C.A. et al. The functional and regulatory roles of sigma factors in transcription. Cold Spring Harb. Symp. Quant. Biol. 63, 141– 155 (1998).

    Article  CAS  PubMed  Google Scholar 

  2. Sasse-Dwight, S. & Gralla, J.D. Role of eukaryotic-type functional domains found in the prokaryotic enhancer receptor factor σ54. Cell 62, 945– 954 (1990).

    Article  CAS  PubMed  Google Scholar 

  3. Reitzer, L.J. & Magasanik, B. Transcription of glnA in E. coli is stimulated by activator bound to sites far from the promoter . Cell 45, 785–792 (1986).

    Article  CAS  PubMed  Google Scholar 

  4. Popham, D.L., Szeto, D., Keener, J. & Kustu, S. Function of a bacterial activator protein that binds to transcriptional enhancers. Science 243, 629–635 ( 1989).

    Article  CAS  PubMed  Google Scholar 

  5. Wedel, A. & Kustu, S. The bacterial enhancer-binding protein NtrC is a molecular machine: ATP hydrolysis is coupled to transcriptional activation. Genes Dev. 9, 2042– 2052 (1995).

    Article  CAS  PubMed  Google Scholar 

  6. Cannon, W., Gallegos, M.T., Casaz, P. & Buck, M. Amino terminal sequences of σN54) inhibit RNA polymerase isomerisation. Genes Dev. 13, 357– 370 (1999).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  7. Neuwald, A.F., Aravind, L., Spouge, J.L. & Koonin, E.V. AAA+: a class of chaperone-like ATPases associated with the assembly, operation, and disassembly of protein complexes. Genome Res. 9, 27– 43 (1999).

    CAS  PubMed  Google Scholar 

  8. Wang, J.T., Syed, A. & Gralla, J.D. Multiple pathways to bypass the enhancer requirement of sigma 54 RNA polymerase: roles for DNA and protein determinants. Proc. Natl. Acad. Sci. USA 94, 9538–9543 ( 1997).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  9. Gallegos, M.T. & Buck, M. Sequences in region I required for binding to early melted DNA and their involvement in sigma-DNA isomerisation . J. Mol. Biol. 297, 849– 859 (2000).

    Article  CAS  PubMed  Google Scholar 

  10. Hsieh, M. & Gralla, J.D. Analysis of the N-terminal leucine heptad and hexad repeats of sigma 54. J. Mol. Biol. 239, 15–24 (1994).

    Article  CAS  PubMed  Google Scholar 

  11. Hsieh, M., Tintut, Y. & Gralla, J.D. Functional roles for the glutamines within the glutamine-rich region of the transcription factor sigma 54. J. Biol. Chem. 269, 373–378 (1994).

    CAS  PubMed  Google Scholar 

  12. Syed, A. & Gralla, J.D. Identification of an N-terminal region of sigma 54 required for enhancer responsiveness. J. Bacteriol. 180, 5619–5625 ( 1998).

    CAS  PubMed  PubMed Central  Google Scholar 

  13. Merrick, M.J. In a class of its own-the RNA polymerase sigma factor sigma 54 (sigma N). Mol. Microbiol. 10, 903–909 (1993).

    Article  CAS  PubMed  Google Scholar 

  14. Morris, L., Cannon, W., Claverie-Martin, F., Austin, S. & Buck, M. DNA distortion and nucleation of local DNA unwinding within sigma-54 (σN) holoenzyme closed promoter complexes. J. Biol. Chem. 269, 11563–11571 (1994).

    CAS  PubMed  Google Scholar 

  15. Wang, J.T., Syed, A., Hsieh, M. & Gralla, J.D. Converting Escherichia coli RNA polymerase into an enhancer-responsive enzyme: role of an NH2-terminal leucine patch in sigma 54. Science 270, 992–994 ( 1995).

    Article  CAS  PubMed  Google Scholar 

  16. Wang, J.T. & Gralla, J.D. The transcription initiation pathway of sigma 54 mutants that bypass the enhancer protein requirement. Implications for the mechanism of activation. J. Biol. Chem. 271 , 32707–32713 (1996).

    Article  CAS  PubMed  Google Scholar 

  17. Gallegos, M.T. & Buck, M. Sequences in σN determining holoenzyme formation and properties. J. Mol. Biol. 288, 539–553 ( 1999).

    Article  CAS  PubMed  Google Scholar 

  18. Casaz, P. & Buck, M. Probing the assembly of transcription initiation complexes through changes in σN protease sensitivity . Proc. Natl. Acad. Sci. USA 94, 12145– 12150 (1997).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  19. Casaz, P. & Buck, M. Region I modifies DNA binding domain conformation of sigma 54 holoenzyme. J. Mol. Biol. 285, 507–514 (1999).

    Article  CAS  PubMed  Google Scholar 

  20. Chaney, M. & Buck, M. The sigma 54 DNA-binding domain includes a determinant of enhancer responsiveness. Mol. Microbiol. 33, 1200–1209 (1999).

    Article  CAS  PubMed  Google Scholar 

  21. Guo, Y., Wang, L. & Gralla, J.D. A fork junction DNA-protein switch that controls promoter melting by the bacterial enhancer-dependent sigma factor. EMBO J. 18, 3736–3745 (1999).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  22. Wang, L. & Gralla, J.D. Multiple in vivo roles for the −12-region elements of sigma 54 promoters. J. Bacteriol. 180, 5626–5631 (1998).

    CAS  PubMed  PubMed Central  Google Scholar 

  23. Buck, M. & Cannon, W. Specific binding of the transcription factor sigma-54 to promoter DNA. Nature 358, 422 –424 (1992).

    Article  CAS  PubMed  Google Scholar 

  24. Weiss, D.S., Batut, J., Klose, K.E., Keener, J. & Kustu, S. The phosphorylated form of the enhancer-binding protein NTRC has an ATPase activity that is essential for activation of transcription . Cell 67, 155–167 (1991).

    Article  CAS  PubMed  Google Scholar 

  25. González, V., Olvera, L., Soberón, X. & Morett, E. In vivo studies on the positive control function of NifA: a conserved hydrophobic amino acid patch at the central domain involved in transcriptional activation. Mol. Microbiol. 28, 55– 67 (1998).

    Article  PubMed  Google Scholar 

  26. Wang, Y.K. & Hoover, T.R. Alterations within the activation domain of the sigma 54-dependent activator DctD that prevent transcriptional activation. J. Bacteriol. 179, 5812– 5819 (1997).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  27. Oguiza, J.A., Gallegos, M.T., Chaney, M.K., Cannon, W.V. & Buck, M. Involvement of the σN DNA-binding domain in open complex formation. Mol. Microbiol. 33 , 873–885 (1999).

    Article  CAS  PubMed  Google Scholar 

  28. Jovanovic, G., Rakonjac, J. & Model, P. In vivo and in vitro activities of the Escherichia coli σ54 transcription activator, PspF, and its DNA-binding mutant, PspFΔHTH . J. Mol. Biol. 285, 469– 483 (1999).

    Article  CAS  PubMed  Google Scholar 

  29. Austin, S., Buck, M., Cannon, W., Eydmann, T. & Dixon, R. Purification and in vitro activities of the native nitrogen fixation control proteins NifA and NifL. J. Bacteriol. 176, 3460–3465 ( 1994).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  30. Hunt, T.P. & Magasanik, B. Transcription of glnA by purified Escherichia coli components: core RNA polymerase and the products of glnF, glnG, and glnL. Proc. Natl. Acad. Sci. USA 82, 8453–8457 ( 1985).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  31. Klose, K.E., North, A.K., Stedman, K.M. & Kustu, S. The major dimerization determinants of the nitrogen regulatory protein NtrC from enteric bacteria lie in its carboxy-terminal domain. J. Mol. Biol. 241 , 233–245 (1994).

    Article  CAS  PubMed  Google Scholar 

  32. Rombel, I., North, A., Hwang, I., Wyman, C. & Kustu, S. The bacterial enhancer-binding protein NtrC as a molecular machine. Cold Spring Harb. Symp. Quant. Biol. 63, 157–166 (1998).

    Article  CAS  PubMed  Google Scholar 

  33. Lee, J.H. & Hoover, T.R. Protein crosslinking studies suggest that Rhizobium meliloti C4-dicarboxylic acid transport protein D, a sigma 54-dependent transcriptional activator, interacts with sigma 54 and the beta subunit of RNA polymerase. Proc. Natl. Acad. Sci. USA 92, 9702–9706 ( 1995).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  34. Gallegos, M.T., Cannon, W. & Buck, M. Functions of the σ54 region I in trans and implications for transcription activation. J. Biol. Chem. 274, 25285–25290 (1999).

    Article  CAS  PubMed  Google Scholar 

  35. Buckle, M., Pemberton, I.K., Jacquet, M.A. & Buc, H. The kinetics of sigma subunit directed promoter recognition by E. coli RNA polymerase. J. Mol. Biol. 285, 955–964 (1999).

    Article  CAS  PubMed  Google Scholar 

  36. Reinberg et al. The RNA polymerase II general transcription factors: past, present and future. Cold Spring Harb. Symp. Quant. Biol. 63, 83– 103 (1998).

    Article  CAS  PubMed  Google Scholar 

  37. Fu, J. et al. Yeast RNA polymerase II at 5 Å resolution. Cell 98, 799–810 (1999).

    Article  CAS  PubMed  Google Scholar 

  38. Zhang, G. et al. Crystal structure of Thermus aquaticus core RNA polymerase at 3.3 Å resolution. Cell 98, 811– 824 (1999).

    Article  CAS  PubMed  Google Scholar 

  39. Tinker-Kulberg, R.L., Fu, T.J., Geiduschek, E.P. & Kassavetis, G.A. A direct interaction between a DNA-tracking protein and a promoter recognition protein: implications for searching DNA sequence. EMBO J. 15, 5032–5039 (1996).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  40. Cannon, W. et al. Core RNA polymerase and promoter DNA interactions of purified domains of sigma N: bipartite functions. J. Mol. Biol. 248, 781–803 (1995).

    Article  CAS  PubMed  Google Scholar 

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Acknowledgements

Work was supported by a Wellcome trust project grant to M.B. M.T.G. was supported by a CEC Marie Curie fellowship. We thank S. Kustu, L.J. Reitzer, R. Wassem and S.R. Wigneshweraraj for purified activator proteins, E. Morett for the pspF mutants, D. Studholme for valuable comments on the manuscript and P. Geiduschek for his constructive comments on the early work.

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Correspondence to Martin Buck.

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Cannon, W., Gallegos, MT. & Buck, M. Isomerization of a binary sigma–promoter DNA complex by transcription activators. Nat Struct Mol Biol 7, 594–601 (2000). https://doi.org/10.1038/76830

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