Linked Life Data

6456268

Source:http://linkedlifedata.com/resource/pubmed/id/6456268

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
19
pubmed:dateCreated
1981-11-22
pubmed:abstractText
The contribution of proofreading to the fidelity by which Escherichia coli DNA polymerase I copies natural DNA has been analyzed by two independent criteria. With phi X174 am 3 DNA as a template, there is approximately a 25-fold increase in noncomplementary base substitutions at position 587 when the concentration of the next correct nucleotide, dATP, is increased. Sequence analysis indicates that the mistakes represent misincorporation of C in place of T at position 587. This mutagenic response is presumed to result from a decrease in the probability of excision by the 3' leads to 5' exonuclease of Pol I and is considered within the context of current theories on proofreading. No enhanced mutagenicity is observed with avian myeloblastosis virus DNA polymerase, which lacks a 3' leads to 5' exonuclease. Using a second approach, an enhancement in mutagenesis as large as 30-fold is observed to result from the addition of deoxynucleoside monophosphates to the Pol I reaction. This mutagenicity occurs with any of the four deoxynucleoside monophosphates and is independent of a significant inhibition of DNA synthesis, thus supporting proofreading models in which sites of excision and incorporation are independent. The results of both approaches suggest that the exonucleolytic activity of Pol I can increase fidelity by approximately 30-fold on natural DNA, a value much higher than previous estimates with polynucleotide templates. The effect of the next correct nucleotide in decreasing accuracy provides an in vitro probe for screening eukaryotic cells for putative proofreading functions.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
10
pubmed:volume
256
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
9883-9
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1981
pubmed:articleTitle
On the fidelity of DNA replication. Effect of the next nucleotide on proofreading.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't