Linked Life Data

2719911

Source:http://linkedlifedata.com/resource/pubmed/id/2719911

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1989-6-27
pubmed:abstractText
The effect of alkyl group size on ability to act as deoxythymidine triphosphate (dTTP) has been studied for the carcinogen products O2-methyl-, O2-ethyl-, and O2-isopropyl-dTTP by using three types of nucleic acids as template and DNA polymerase I (Pol I) or Klenow fragment as the polymerizing enzymes. Apparent Km and relative Vmax values were determined in primer extension on M13 DNA at a single defined site, in poly[d(A-T)], and in nicked DNA. These data are the basis for calculation of the relative rate of insertion opposite A, relative to dTTP. The insertion rate for any O2-alkyl-dTTP is much higher than for a mismatch between unmodified dNTPs. Unexpectedly, O2-isopropyl-dTTP is more efficiently utilized than O2-methyl-dTTP or O2-ethyl-dTTP on each of the templates. O2-isopropyl-dTTP also substitutes for dTTP over extended times of DNA synthesis at a rate only slightly lower than that of dTTP. Parallel experiments using O4-methyl-dTTP under the same conditions show that it is incorporated opposite A more frequently than is O2-methyl-dTTP. Therefore, both the ring position and the size of the alkyl group influence polymerase recognition. Once formed, all O2-alkyl-T.A termini permit elongation, as does O4-methyl-T.A. In contrast to the relative difficulty of incorporating the O-alkyl-dTTPs, formation of the following normal base pair (C.G) occurs rapidly when dGTP is present. This indicates that a single O-alkyl-T.A pair does not confer significant structural distortion recognized by Pol I.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
21
pubmed:volume
28
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1478-83
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
Comparison of polymerase insertion and extension kinetics of a series of O2-alkyldeoxythymidine triphosphates and O4-methyldeoxythymidine triphosphate.
pubmed:affiliation
Donner Laboratory, Lawrence Berkeley Laboratory, University of California, Berkeley 94720.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.