Title

Role of Human DNA Polymerase k in Extension Opposite from a cis-syn Thymine Dimer

Publication Date

2011

Document Type

Article

Abstract

Exposure of DNA to UV radiation causes covalent linkages between adjacent pyrimidines. The most common lesion found in DNA from these UV-induced linkages is the cissyn cyclobutane pyrimidine dimer. Human DNA polymerase κ (Polκ), a member of the Y-family of DNA polymerases, is unable to insert nucleotides opposite the 3′T of a cissyn T-T dimer, but it can efficiently extend from a nucleotide inserted opposite the 3′T of the dimer by another DNA polymerase. We present here the structure of human Polκ in the act of inserting a nucleotide opposite the 5′T of the cissyn T-T dimer. The structure reveals a constrained active-site cleft that is unable to accommodate the 3′T of a cissyn T-T dimer but is remarkably well adapted to accommodate the 5′T via Watson–Crick base pairing, in accord with a proposed role for Polκ in the extension reaction opposite from cyclobutane pyrimidine dimers in vivo.

Original Citation

Vasquez-Del Carpio, Rodrigo; Silverstein, Timothy D.; Lone, Samer; Johnson, Robert E.; Prakash, Louise; Prakash, Satya; Aggarwal, Aneel K. (2011). Role of Human DNA Polymerase k in Extension Opposite from a cis-syn Thymine Dimer. Journal of Molecular Biology, 408(2), 252-261. https://doi.org/10.1016/j.jmb.2011.02.042