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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1992-3-24
pubmed:abstractText
The use of unequal concentrations of the four deoxynucleoside triphosphates (dNTPs) in DNA polymerization reactions alters base substitution error rates in a predictable way. Less is known about the effects of substrate imbalances on base addition and deletion error rates. Thus, we examined pool bias effects on frameshift fidelity during DNA synthesis catalyzed by replicative DNA polymerases. Imbalanced pools altered the frameshift fidelity of the human immunodeficiency virus type-1 reverse transcriptase. Both mutagenic and antimutagenic effects were observed for minus-one, plus-one, and minus-two nucleotide errors, in a highly sequence-specific manner. Most of this specificity can be rationalized by either of two models. One involves frameshifts initiated by pool bias-induced nucleotide misinsertion, and the other involves pool bias-initiated template-primer slippage. Several examples of complex mutations were also recovered more than once in small mutant collections. These contained closely spaced single-base substitution and minus-one base frameshift changes. The two changes occurred at a frequency much higher than predicted if they were generated independently. This suggests that when the polymerase makes one mistake, the probability that it will make a second mistake within the next few incorporations increases significantly. Perturbation of dNTP pools also affected the frameshift fidelity of the replicative yeast DNA polymerase alpha. In reactions containing a low concentration of one dNTP, the error rate increased for one-nucleotide deletions at homopolymeric template nucleotides complementary to the dNTP whose concentration was low. We extended this approach to determine the frameshift fidelity of simian virus 40 origin-dependent semiconservative replication of double-stranded DNA in extracts of human cells. In reactions performed with an equal concentration of all four dNTPs, replication was highly accurate for minus-one-nucleotide errors. However, when the concentration of one dNTP was decreased, the replication error rate increased at complementary, homopolymeric template positions. This response provides an approach for describing frameshift accuracy during replication of the leading and lagging strands.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
267
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3589-96
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
The effects of dNTP pool imbalances on frameshift fidelity during DNA replication.
pubmed:affiliation
Laboratory of Molecular Genetics, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.