Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
21
pubmed:dateCreated
2003-5-19
pubmed:abstractText
DNA polymerase eta (Pol eta) is a member of a new class of DNA polymerases that is able to copy DNA containing damaged nucleotides. These polymerases are highly error-prone during copying of unaltered DNA templates. We analyzed the relationship between bypass efficiency and fidelity of DNA synthesis by introducing substitutions for Tyr-52, a highly conserved amino acid, within the human DNA polymerase eta (hPol eta) finger domain. Most substitutions for Tyr-52 caused reduction in bypass of UV-associated damage, measured by the ability to rescue the viability of UV-sensitive yeast cells at a high UV dose. For most mutants, the reduction in bypass ability paralleled the reduction in polymerization activity. Interestingly, the hPol eta Y52E mutant exhibited a greater reduction in bypass efficiency than polymerization activity. The reduction in bypass efficiency was accompanied by an up to 11-fold increase in the incorporation of complementary nucleotides relative to non-complementary nucleotides. The fidelity of DNA synthesis, measured by copying a gapped M13 DNA template in vitro, was also enhanced as much as 15-fold; the enhancement resulted from a decrease in transitions, which were relatively frequent, and a large decrease in transversions. Our demonstration that an amino acid substitution within the active site enhances the fidelity of DNA synthesis by hPol eta, one of the most inaccurate of DNA polymerases, supports the hypothesis that even error-prone DNA polymerases function in base selection.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
23
pubmed:volume
278
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
19341-6
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:12644469-Binding Sites, pubmed-meshheading:12644469-DNA, pubmed-meshheading:12644469-DNA Damage, pubmed-meshheading:12644469-DNA-Directed DNA Polymerase, pubmed-meshheading:12644469-Escherichia coli, pubmed-meshheading:12644469-Gene Expression, pubmed-meshheading:12644469-Gene Library, pubmed-meshheading:12644469-Humans, pubmed-meshheading:12644469-Kinetics, pubmed-meshheading:12644469-Models, Molecular, pubmed-meshheading:12644469-Mutagenesis, Site-Directed, pubmed-meshheading:12644469-Polymerase Chain Reaction, pubmed-meshheading:12644469-Purines, pubmed-meshheading:12644469-Pyrimidines, pubmed-meshheading:12644469-Saccharomyces cerevisiae, pubmed-meshheading:12644469-Structure-Activity Relationship, pubmed-meshheading:12644469-Templates, Genetic, pubmed-meshheading:12644469-Transfection, pubmed-meshheading:12644469-Tyrosine, pubmed-meshheading:12644469-Ultraviolet Rays
pubmed:year
2003
pubmed:articleTitle
Amino acid substitutions at conserved tyrosine 52 alter fidelity and bypass efficiency of human DNA polymerase eta.
pubmed:affiliation
The Joseph Gottstein Memorial Cancer Research Laboratory, Department of Pathology, University of Washington, Seattle, Washington 98195-357705, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't