Linked Life Data

8011648

Source:http://linkedlifedata.com/resource/pubmed/id/8011648

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
25
pubmed:dateCreated
1994-7-26
pubmed:abstractText
The solution secondary structures and nucleotide conformations in the telomeric DNA of Oxytricha nova have been determined by Raman spectroscopy. Structural polymorphism is demonstrated for both single-stranded [d(T4G4)4] and double-stranded [d(G4T4G4).d(C4A4C4)] telomere models. In the case of d(T4G4)4, which is a prototype for the single-stranded telomeric tail, an interquadruplex equilibrium involving parallel and antiparallel strand configurations is shown to be governed by the solution concentrations of both Na+ and K+. In both the parallel and antiparallel quadruplexes of d(T4G4)4, the local geometry of the phosphodiester backbone is similar to that of canonical B DNA, and associations between bases of the guanine quartet involve Hoogsteen hydrogen bonding. However, the deoxyguanosine (dG) sugar conformations are significantly different in the two quadruplexes. In the extended parallel form, dG residues assume only the C2'-endo/anti conformation with respect to deoxyribose pucker and glycosyl orientation. In the foldback antiparallel form, dG residues are distributed equally between C2'-endo/anti and C2'-endo/syn conformations. In the case of d(G4T4G4).d(C4A4C4), which serves as a model for the double-stranded B DNA regions of Oxytricha telomeres, we show that disproportionation of the B form duplex to yield stable parallel quadruplexes of the guanine-rich strand occurs reversibly at high solution concentrations of either Na+ or K+. The present study reveals that both interquadruplex and duplex-quadruplex conversions of Oxytricha telomeric DNA are under the control of an alkali cation switch.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:grant
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
28
pubmed:volume
33
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
7848-56
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
Structural polymorphism of telomere DNA: interquadruplex and duplex-quadruplex conversions probed by Raman spectroscopy.
pubmed:affiliation
Division of Cell Biology and Biophysics, School of Biological Sciences, University of Missouri, Kansas City 64110-2499.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't