Linked Life Data

9811542

Source:http://linkedlifedata.com/resource/pubmed/id/9811542

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1999-2-25
pubmed:abstractText
Although mammalian mitochondrial serine-specific tRNA with the anticodon UGA (tRNASerUGA) appears to possess an almost normal cloverleaf secondary structure, it exhibits an extraordinarily low melting temperature (tm). An in vitro tRNASerUGA transcript without modified nucleosides had an even lower tm and slightly less hyperchromicity, but its tertiary structure was apparently very similar to that of the native counterpart judging from its aminoacylation activity and the body of experimental evidence so far obtained for canonical tRNAs. The transcript was therefore used to investigate the higher-order structure and thermal instability of tRNASerUGA. 1H-NMR analysis of the transcript showed that it takes a nearly L-shaped tertiary structure with similar tertiary base-pairings to those found in yeast tRNAPhe, which is representative of canonical tRNAs. However, magnesium ion titration revealed that Mg2+ affected the chemical shifts of the tRNASerUGA transcript differently than those of canonical tRNAs so far studied; the former was less sensitive toward Mg2+, especially in the D-arm region. This observation was confirmed by NMR analysis with paramagnetic manganese ion titration. Hill plots derived from the CD spectral changes caused by titration with Mg2+ suggested that the tRNASerUGA transcript had fewer Mg2+ binding sites than those of yeast tRNAPhe as well as its transcript, a finding that was consistent with the NMR data. We thus surmise that the thermal instability of both the transcript and tRNASerUGA itself originated from a reduction in the number of the divalent ion binding sites within the tRNA molecule. These results suggest a new type of thermal instability for mitochondrial tRNA.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0022-2836
pubmed:author
pubmed:copyrightInfo
Copyright 1998 Academic Press
pubmed:issnType
Print
pubmed:day
20
pubmed:volume
284
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
57-69
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Higher-order structure and thermal instability of bovine mitochondrial tRNASerUGA investigated by proton NMR spectroscopy.
pubmed:affiliation
Graduate School of Engineering, University of Tokyo, 7-3-1 Hongo, Tokyo, Bunkyo-ku, 113-8656, Japan.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't