Linked Life Data

3315998

Source:http://linkedlifedata.com/resource/pubmed/id/3315998

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
84
pubmed:dateCreated
1988-1-12
pubmed:abstractText
The O2- and O4-methyldeoxythymidine triphosphates (O-alkyl dTTP) can be used to substitute for dTTP in Escherichia coli DNA polymerase I (Pol I)-catalysed synthesis of poly[deoxyadenosine-deoxythymidine] (dA-dT). When incorporated into the polynucleotide, no detectable perturbation of structure occurred with even 20% O-methyldeoxythymidine in place of dT. However, on replication of such polymers with Pol I, significant amounts of deoxyguanosine triphosphate (dGTP) were incorporated, as well as high levels of deoxyadenosine triphosphate (dATP), indicating tautomer-like behaviour. Higher homologues, such as O4-ethyl (e4) dTTP or O4-isopropyl (ip4) dTTP, could also replace dTTP, but with lower efficiency. Nevertheless, their presence, like O4-methyl (m4) dT substitutions, caused transitions as well as inhibiting enzyme digestion with a variety of 3' nucleases, particularly to the 3'----5' exonuclease activity (proofreading) of polymerases. Further proof of mutagenicity comes from site-directed experiments placing m4dT or e4dT in place of dT at position 587 in am3 of phi X174, in which all revertants sequenced had A----G transitions. This implies that, since m4dT and e4dT are poorly repaired in eukaryotes, it is likely that they will remain in the DNA and lead to effects on enzyme activity, as well as mutations which contribute to the carcinogenicity of N-nitroso compounds.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0300-5038
pubmed:author
pubmed:issnType
Print
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
37-40
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1987
pubmed:articleTitle
O-Alkyl deoxythymidines are recognized by DNA polymerase I as deoxythymidine or deoxycytidine.
pubmed:affiliation
Donner Laboratory, University of California, Berkeley 94720.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't