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  • The EMBO Journal (2000) 19, 3100 - 3109
  • doi:10.1093/emboj/19.12.3100

Mechanisms of accurate translesion synthesis by human DNA polymerase eta

Chikahide Masutani1,5, Rika Kusumoto1,2,5, Shigenori Iwai3 and Fumio Hanaoka1,4

  1. Institute for Molecular and Cellular Biology, Osaka University, and CREST, Japan Science and Technology Corporation , 1-3 Yamada-oka, Suita, Osaka 565-0871, Japan
  2. The Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamada-oka, Suita, Osaka 565-0871, Japan
  3. Biomolecular Engineering Research Institute, 6-2-3 Furuedai, Suita, Osaka 565-0874, Japan
  4. RIKEN (The Institute of Physical and Chemical Research), Wako-shi, Saitama 351-0198, Japan
  5. C.Masutani and R.Kusumoto contributed equally to this work

Correspondence to:

Fumio Hanaoka, E-mail: fhanaoka@imcb.osaka-u.ac.jp

Received 29 March 2000; Accepted 26 April 2000; Revised 26 April 2000

The XPV (xeroderma pigmentosum variant) gene encodes human DNA polymerase eta (pol eta), which is involved in the replication of damaged DNA. Pol eta catalyzes efficient and accurate translesion synthesis past cis-syn cyclobutane di-thymine lesions. Here we show that human pol eta can catalyze translesion synthesis past an abasic (AP) site analog, N-2-acetylaminofluorene (AAF)-modified guanine, and a cisplatin-induced intrastrand cross-link between two guanines. Pol eta preferentially incorporated dAMP and dGMP opposite AP, and dCMP opposite AAF-G and cisplatin-GG, but other nucleotides were also incorporated opposite these lesions. However, after incorporating an incorrect nucleotide opposite a lesion, pol eta could not continue chain elongation. In contrast, after incorporating the correct nucleotide opposite a lesion, pol eta could continue chain elongation, whereas pol alpha could not. Thus, the fidelity of translesion synthesis by human pol eta relies not only on the ability of this enzyme to incorporate the correct nucleotide opposite a lesion, but also on its ability to elongate only DNA chains that have a correctly incorporated nucleotide opposite a lesion.

  • Keywords:

    • DNA polymerase eta,
    • translesion synthesis,
    • xeroderma pigmentosum variant (XP-V)