Journal article
Mismatch extension ability of yeast and human DNA polymerase eta
The Journal of biological chemistry, Vol.276(3), pp.2263-2266
01/19/2001
DOI: 10.1074/jbc.M009049200
PMID: 11054429
Abstract
DNA polymerase eta (Poleta) functions in error-free replication of UV-damaged DNA, and in vitro it efficiently bypasses a cis-syn T-T dimer by incorporating two adenines opposite the lesion. Steady state kinetic studies have shown that both yeast and human Poleta are low-fidelity enzymes, and they misincorporate nucleotides with a frequency of 10(-2)-10(-3) on both undamaged and T-T dimer-containing DNA templates. To better understand the role of Poleta in error-free translesion DNA synthesis, here we examine the ability of Poleta to extend from base mismatches. We find that both yeast and human Poleta extend from mismatched base pairs with a frequency of approximately 10(-3) relative to matched base pairs. In the absence of efficient extension of mismatched primer termini, the ensuing dissociation of Poleta from DNA may favor the excision of mismatched nucleotides by a proofreading exonuclease. Thus, we expect DNA synthesis by Poleta to be more accurate than that predicted from the fidelity of nucleotide incorporation alone.
Details
- Title: Subtitle
- Mismatch extension ability of yeast and human DNA polymerase eta
- Creators
- M Todd Washington - Sealy Center for Molecular Science, University of Texas Medical Branch, Galveston, Texas 77555-1061, USARobert E JohnsonSatya PrakashLouise Prakash
- Resource Type
- Journal article
- Publication Details
- The Journal of biological chemistry, Vol.276(3), pp.2263-2266
- DOI
- 10.1074/jbc.M009049200
- PMID
- 11054429
- NLM abbreviation
- J Biol Chem
- ISSN
- 0021-9258
- eISSN
- 1083-351X
- Publisher
- United States
- Grant note
- GM19261 / NIGMS NIH HHS
- Language
- English
- Date published
- 01/19/2001
- Academic Unit
- Radiation Oncology; Biochemistry and Molecular Biology
- Record Identifier
- 9984024564302771
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