Linked Life Data

7524665

Source:http://linkedlifedata.com/resource/pubmed/id/7524665

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
46
pubmed:dateCreated
1994-12-21
pubmed:abstractText
Phylogenetically invariant G.U wobble pairs are present in a wide variety of RNA's. As a means to study the contribution of individual chemical groups within a G.U pair, we have synthesized and thermodynamically characterized oligoribonucleotides containing the unnatural nucleosides 2,6-diaminopurine riboside (DAP) and 5-methylisocytidine (MeiC). The DAP.MeiC pair at the end of an RNA duplex is as stable as a G.U pair, consistent with formation of a wobble base pair with two hydrogen bonds. DAP.MeiC is a valuable substitution for the study of G.U wobble pairs because it is conformationally similar to the G.U pair, but has a different array of functional groups in the major and minor grooves of the duplex and a reversed hydrogen bonding polarity between the bases. We also report the stability of several other terminal pairs proposed to be in a wobble configuration including inosine.U (I.U), A.MeiC, DAP.C, A.C, G.5-methyl-U,2'-deoxyguanosine.U, and 2'-deoxy-7-deazaguanosine.U. These pairs present a diversity of functional group substitutions in the context of a wobble conformation. Comparison of wobble pairs with and without the N2 exocyclic amine, i.e., G.U vs I.U, DAP.MeiC vs A.MeiC, and DAP.C vs A.C, demonstrates that the amine does not contribute to base pairing stability when the pair is located at the terminal position of the RNA duplex. However, at a position internal to the duplex, the exocyclic amine does improve helix stability. An internal I.U pair is less stable (approximately 1 kcal.mol-1) than an internal G.U pair, and substantially less stable (approximately 2 kcal.mol-1) than an internal A-U pair. These data provide quantitation for the reduced duplex stability observed upon conversion of A-U to I.U pairs by double-stranded RNA adenosine deaminase (dsRAD). This collection of wobble pairs will help identify the contribution made by individual functional groups in RNA/protein interactions and in the tertiary folding of RNA.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
22
pubmed:volume
33
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
13824-35
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
The 2,6-diaminopurine riboside.5-methylisocytidine wobble base pair: an isoenergetic substitution for the study of G.U pairs in RNA.
pubmed:affiliation
Howard Hughes Medical Institute, University of Colorado, Boulder 80309-0215.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't