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. 1990 Nov;87(21):8452–8456. doi: 10.1073/pnas.87.21.8452

Role of tryptophan repeats and flanking amino acids in Myb-DNA interactions.

P Saikumar 1, R Murali 1, E P Reddy 1
PMCID: PMC54974  PMID: 2236054

Abstract

The c-myb protooncogene codes for a sequence-specific DNA-binding protein that appears to act as a transcriptional regulator and is highly conserved through evolution. The DNA-binding domain of Myb has been shown to contain three imperfectly conserved repeats of 52 amino acids that constitute the amino-terminal end. Within each repeat, there are three tryptophans that are separated by 18 or 19 amino acids and are flanked by basic amino acids. To determine the role of tryptophans and the flanking basic amino acids in the DNA-binding activity of Myb proteins, we have selectively mutagenized individual tryptophans as well as some of the amino acid residues that flank these tryptophans. Replacement of these tryptophans with glycine, proline, or arginine abolished the DNA-binding activity whereas replacement with other aromatic amino acids or leucine or alanine did not appreciably affect this activity. On the other hand the replacement of two amino acids, asparagine and lysine, that flank the last tryptophan with acidic amino acids completely abolished their DNA-binding activity. These results are consistent with a model we present in which the tryptophans form a hydrophobic scaffold that plays a crucial role in maintaining the helix-turn-helix structure of the DNA binding domain. Basic and polar amino acids adjacent to these tryptophans seem to participate directly in DNA binding.

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Selected References

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

  1. Anderson J. E., Ptashne M., Harrison S. C. Structure of the repressor-operator complex of bacteriophage 434. 1987 Apr 30-May 6Nature. 326(6116):846–852. doi: 10.1038/326846a0. [DOI] [PubMed] [Google Scholar]
  2. Anton I. A., Frampton J. Tryptophans in myb proteins. Nature. 1988 Dec 22;336(6201):719–719. doi: 10.1038/336719a0. [DOI] [PubMed] [Google Scholar]
  3. Bender T. P., Kuehl W. M. Murine myb protooncogene mRNA: cDNA sequence and evidence for 5' heterogeneity. Proc Natl Acad Sci U S A. 1986 May;83(10):3204–3208. doi: 10.1073/pnas.83.10.3204. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Benedetti E., Morelli G., Némethy G., Scheraga H. A. Statistical and energetic analysis of side-chain conformations in oligopeptides. Int J Pept Protein Res. 1983 Jul;22(1):1–15. doi: 10.1111/j.1399-3011.1983.tb02062.x. [DOI] [PubMed] [Google Scholar]
  5. Berg J. M. Zinc fingers and other metal-binding domains. Elements for interactions between macromolecules. J Biol Chem. 1990 Apr 25;265(12):6513–6516. [PubMed] [Google Scholar]
  6. Biedenkapp H., Borgmeyer U., Sippel A. E., Klempnauer K. H. Viral myb oncogene encodes a sequence-specific DNA-binding activity. Nature. 1988 Oct 27;335(6193):835–837. doi: 10.1038/335835a0. [DOI] [PubMed] [Google Scholar]
  7. Dudek H., Reddy E. P. Identification of two translational products for c-myb. Oncogene. 1989 Sep;4(9):1061–1066. [PubMed] [Google Scholar]
  8. Dudek H., Reddy E. P. Murine myeloid leukemias with aberrant myb loci show heterogeneous expression of novel myb proteins. Oncogene. 1989 Dec;4(12):1489–1495. [PubMed] [Google Scholar]
  9. Frampton J., Leutz A., Gibson T., Graf T. DNA-binding domain ancestry. Nature. 1989 Nov 9;342(6246):134–134. doi: 10.1038/342134a0. [DOI] [PubMed] [Google Scholar]
  10. Gentz R., Rauscher F. J., 3rd, Abate C., Curran T. Parallel association of Fos and Jun leucine zippers juxtaposes DNA binding domains. Science. 1989 Mar 31;243(4899):1695–1699. doi: 10.1126/science.2494702. [DOI] [PubMed] [Google Scholar]
  11. Higuchi R., Krummel B., Saiki R. K. A general method of in vitro preparation and specific mutagenesis of DNA fragments: study of protein and DNA interactions. Nucleic Acids Res. 1988 Aug 11;16(15):7351–7367. doi: 10.1093/nar/16.15.7351. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Howe K. M., Reakes C. F., Watson R. J. Characterization of the sequence-specific interaction of mouse c-myb protein with DNA. EMBO J. 1990 Jan;9(1):161–169. doi: 10.1002/j.1460-2075.1990.tb08092.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Kouzarides T., Ziff E. The role of the leucine zipper in the fos-jun interaction. Nature. 1988 Dec 15;336(6200):646–651. doi: 10.1038/336646a0. [DOI] [PubMed] [Google Scholar]
  14. Majello B., Kenyon L. C., Dalla-Favera R. Human c-myb protooncogene: nucleotide sequence of cDNA and organization of the genomic locus. Proc Natl Acad Sci U S A. 1986 Dec;83(24):9636–9640. doi: 10.1073/pnas.83.24.9636. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Ness S. A., Marknell A., Graf T. The v-myb oncogene product binds to and activates the promyelocyte-specific mim-1 gene. Cell. 1989 Dec 22;59(6):1115–1125. doi: 10.1016/0092-8674(89)90767-8. [DOI] [PubMed] [Google Scholar]
  16. Oehler T., Arnold H., Biedenkapp H., Klempnauer K. H. Characterization of the v-myb DNA binding domain. Nucleic Acids Res. 1990 Apr 11;18(7):1703–1710. doi: 10.1093/nar/18.7.1703. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Pabo C. O., Sauer R. T. Protein-DNA recognition. Annu Rev Biochem. 1984;53:293–321. doi: 10.1146/annurev.bi.53.070184.001453. [DOI] [PubMed] [Google Scholar]
  18. Paz-Ares J., Ghosal D., Wienand U., Peterson P. A., Saedler H. The regulatory c1 locus of Zea mays encodes a protein with homology to myb proto-oncogene products and with structural similarities to transcriptional activators. EMBO J. 1987 Dec 1;6(12):3553–3558. doi: 10.1002/j.1460-2075.1987.tb02684.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Peters C. W., Sippel A. E., Vingron M., Klempnauer K. H. Drosophila and vertebrate myb proteins share two conserved regions, one of which functions as a DNA-binding domain. EMBO J. 1987 Oct;6(10):3085–3090. doi: 10.1002/j.1460-2075.1987.tb02616.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Rosson D., Dugan D., Reddy E. P. Aberrant splicing events that are induced by proviral integration: implications for myb oncogene activation. Proc Natl Acad Sci U S A. 1987 May;84(10):3171–3175. doi: 10.1073/pnas.84.10.3171. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Rosson D., Reddy E. P. Nucleotide sequence of chicken c-myb complementary DNA and implications for myb oncogene activation. Nature. 1986 Feb 13;319(6054):604–606. doi: 10.1038/319604a0. [DOI] [PubMed] [Google Scholar]
  22. Sakura H., Kanei-Ishii C., Nagase T., Nakagoshi H., Gonda T. J., Ishii S. Delineation of three functional domains of the transcriptional activator encoded by the c-myb protooncogene. Proc Natl Acad Sci U S A. 1989 Aug;86(15):5758–5762. doi: 10.1073/pnas.86.15.5758. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. Staudt L. M., Singh H., Sen R., Wirth T., Sharp P. A., Baltimore D. A lymphoid-specific protein binding to the octamer motif of immunoglobulin genes. Nature. 1986 Oct 16;323(6089):640–643. doi: 10.1038/323640a0. [DOI] [PubMed] [Google Scholar]
  24. Tice-Baldwin K., Fink G. R., Arndt K. T. BAS1 has a Myb motif and activates HIS4 transcription only in combination with BAS2. Science. 1989 Nov 17;246(4932):931–935. doi: 10.1126/science.2683089. [DOI] [PubMed] [Google Scholar]
  25. Weinstein Y., Ihle J. N., Lavu S., Reddy E. P. Truncation of the c-myb gene by a retroviral integration in an interleukin 3-dependent myeloid leukemia cell line. Proc Natl Acad Sci U S A. 1986 Jul;83(14):5010–5014. doi: 10.1073/pnas.83.14.5010. [DOI] [PMC free article] [PubMed] [Google Scholar]
  26. Weston K., Bishop J. M. Transcriptional activation by the v-myb oncogene and its cellular progenitor, c-myb. Cell. 1989 Jul 14;58(1):85–93. doi: 10.1016/0092-8674(89)90405-4. [DOI] [PubMed] [Google Scholar]

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