Linked Life Data

6210103

Source:http://linkedlifedata.com/resource/pubmed/id/6210103

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
23
pubmed:dateCreated
1985-1-31
pubmed:abstractText
We have investigated the effect of Mg2+ on the solution conformation of two different tRNAs by studying the decay of the fluorescence polarization anisotropy of intercalated ethidium on a nanosecond time scale. In the presence of endogenous Mg2+, yeast tRNAPhe and Escherichia coli tRNAVal1 exhibit similar behavior; i.e., the fluorescence from the intercalated ethidium decays biexponentially with lifetimes of approximately 25 and approximately 5 ns, and the fluorescence polarization anisotropy decays with a lifetime of approximately 25 ns. However, once Mg2+ is removed from the two tRNAs, their behavior is no longer similar. In the case of yeast tRNAPhe, it appears that titrating with Mg2+ restores the tRNA to the condition that it was in prior to the Mg2+ removal. This is not so for E. coli tRNAVal1, in which case titrating with Mg2+ results in a two-component anisotropy decay with lifetimes of approximately 25 and approximately 6 ns. Rudimentary calculations indicate that the 6-ns component does not result simply from a change in conformation of the tRNA. However, torsional motions in the tRNA facilitated by a torsion "joint" with a rigidity approximately 1/40 that of intact linear phi 29 DNA would yield a decay component on this time scale with about the right amplitude. We are thus left with the possibility that (after initially removing magnesium) titrating tRNAVal1 with Mg2+ leads to increased internal flexibility and a significant amplitude of a deformational relaxation mode. At any rate, there is no question that after removal of Mg2+ tRNAPhe and tRNAVal1 display quite different solution conformation behavior. These findings are in qualitative agreement with recent 500-MHz 1H NMR results from solutions of these two tRNAs.
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
6
pubmed:volume
23
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
5414-20
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1984
pubmed:articleTitle
Effect of Mg2+ on solution conformation of two different transfer ribonucleic acids.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S.