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Terminal Deoxynucleotidyl Transferase Help DNA Polymerase α Bypass Thymine Dimer

  • Shonen Yoshida
  • Sigeo Masaki
  • Hiromu Nakamura
  • Toshiteru Morita
Part of the Advances in Experimental Medicine and Biology book series (AEMB, volume 145)

Abstract

The physiological function of terminal deoxynucleotidyl transferase (EC 2.7.7.31) is not known. In 1974, Baltimore (1) proposed a model in which terminal transferase acts as a somatic mutator at a special region of immunoglobulin gene during the maturation of immunocompetent cells. On the other hand, a speculative mechanism for induced mutagenesis in the eukaryotic cell was also discussed in connection with the possible induction of terminal transferase in the cell which has damaged DNA (2), In order to verify these hypothesis, further biochemical analysis may be required with respect to a possible modulation of the DNA polymerase reaction by terminal transferase. Recently, we have shown (3) that the replication by DNA polymerase α stops at the site of thymine dimer induced by ultraviolet-irradiation on the template poly(dT). The addition of terminal deoxynucleotidyl transferase to this system enhanced the DNA synthesis to the control level and it concemittantly increased the incorporation of the mismatched deoxynucleotides into the newly synthesized poly(dA) strand. The sizes of newly synthesized DNA were smaller with ultraviolet irradiated template but they increased to the control level with the addition of terminal deoxynucleotidyl transferase to the system. These results suggest that terminal deoxynucleotidyl transferase can help DNA polymerase α “bypass” thymine dimers in vitro by the formation of mismatched regions at the positions opposite to pyrimidine dimers on the template.

Keywords

Density Gradient Centrifugation Terminal Deoxynucleotidyl Transferase Immunoglobulin Gene Pyrimidine Dimer Terminal Transferase 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. 1.
    Baltimore, D. (l974) Nature 248, 409–411CrossRefGoogle Scholar
  2. 2.
    Villani, G., Boiteux, S. and Radman, M. (l978) Proc. Natl. Acad. Sci. U.S.A. 75, 3O37–304lCrossRefGoogle Scholar
  3. 3.
    Yoshida, S., Masaki, S., Nakamura, H. and Morita, T. (l98l) Biochim. Biophys. Acta, 652, 324–333PubMedCrossRefGoogle Scholar
  4. 4.
    Masaki, S., and Yoshida, S. (l978) Biochim. Biophys. Acta 521, 74–88CrossRefGoogle Scholar

Copyright information

© Plenum Press, New York 1982

Authors and Affiliations

  • Shonen Yoshida
    • 1
  • Sigeo Masaki
    • 1
  • Hiromu Nakamura
    • 2
  • Toshiteru Morita
    • 2
  1. 1.Department of BiochemistryInstitute for Developmental ResearchKasugai, Aichi 480-03Japan
  2. 2.Department of Experimental RadiololyAichi Cancer Center Research InstituteChikusa-ku, Nagoya, 464Japan

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