3pzp

Publication Abstract from PubMed

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 cis-syn cyclobutane pyrimidine dimer. Human DNA polymerase kappa (Polkappa), a member of the Y-family of DNA polymerases, is unable to insert nucleotides opposite the 3'T of a cis-syn 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 Polkappa in the act of inserting a nucleotide opposite the 5'T of the cis-syn T-T dimer. The structure reveals a constrained active-site cleft that is unable to accommodate the 3'T of a cis-syn 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 Polkappa in the extension reaction opposite from cyclobutane pyrimidine dimers in vivo.

Role of human DNA polymerase kappa in extension opposite from a cis-syn thymine dimer.,Vasquez-Del Carpio R, Silverstein TD, Lone S, Johnson RE, Prakash L, Prakash S, Aggarwal AK J Mol Biol. 2011 Apr 29;408(2):252-61. Epub 2011 Feb 24. PMID:21354175^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.