Linked Life Data

9592160

Source:http://linkedlifedata.com/resource/pubmed/id/9592160

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
1998-7-20
pubmed:abstractText
Mature tRNAPhe from Escherichia coli and the transcript of its gene lacking modified nucleotides were compared by a variety of physical techniques. Melting experiments revealed that at a low Mg2+level the transcript was partially denatured, while the mature tRNA possessed intact tertiary interactions. Mg2+binding to both tRNAs was studied by CD and UV techniques as well as by using the Mg2+-sensitive fluorescence indicator, 8-hydroxyquinoline 5-sulfonic acid. Both tRNA forms exhibited a single strong Mg2+-binding site, its dissociation constant was 10-fold higher for the transcript. Conformational changes in response to Mg2+ addition measured by CD and UV spectrometry revealed no difference for the estimated binding cooperativity and strong differences for affinities of Mg2+-binding sites for the two tRNA forms. Conformational transitions in mature and in in vitro synthesized tRNA required the binding of two Mg2+ ions per molecule and therefore should be associated not only with a single strong binding site. The Mg2+ dependence of Stokes radii measured by gel-filtration revealed insignificant differences between the overall sizes of the two tRNA forms at physiological Mg2+ levels (>1 mM). Taken together, these results suggest that modified nucleotides stabilize tertiary interactions and increase the structure stability without affecting the mechanism of Mg2+binding and overall folding of the tRNA molecule. This conclusion is supported by the known biological activity of the E. coli tRNAPhe gene transcript.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0305-1048
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
26
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2723-8
pubmed:dateRevised
2008-11-20
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Mg2+ binding and structural stability of mature and in vitro synthesized unmodified Escherichia coli tRNAPhe.
pubmed:affiliation
Engelhardt Institute of Molecular Biology, Moscow 117984, Russia.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't