Linked Life Data

7776375

Source:http://linkedlifedata.com/resource/pubmed/id/7776375

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1995-7-11
pubmed:abstractText
Dissection of the yeast cytoplasmic initiator tRNA(Met) into two helical domains, the T psi C acceptor and anticodon minihelices, failed to show anminoacylation and binding of the acceptor minihelix by the yeast methionyl-tRNA synthetase (MetRS) even in the presence of the anticodon minihelix. In contrast, based on the measure of the inhibition constant Ki, the anticodon minihelix carrying the methionine anticodon CAU is specifically bound to the synthetase and with an affinity comparable to that of the full-length tRNA. The yeast tRNA(Met) acceptor and anticodon minihelices were covalently linked using the central core sequences of either bovine mitochondrial tRNA(Ser) (AGY) lacking a D-stem or initiator tRNA(Met) from Caenorhabditis elegans lacking a T-stem. Based on modeling studies of analogous constructs performed by others, we assume that the folding and distance between the anticodon and acceptor ends of these hybrid tRNAs are identical to that of canonical tRNA. The three-quarter molecule, which includes the T-stem, has aminoacylation activity significantly more than an acceptor minihelix, while the acceptor stem/anticodon-D stem biloop has near wild-type aminoacylation activity. These results suggest that the high selectivity of the anticodon bases in tRNA(Met) depends upon the tRNA L-shape conformation and the presence of a D-arm. Protein contacts with the D-arm phosphate backbone are required for connecting anticodon recognition with the active site. These interactions probably contribute to fine tune the position of the acceptor end in the active site, allowing entry into the transition state of aminoacylation upon anticodon binding. The importance of an L structure for recognition of tRNA(Met) by yeast MetRS was also deduced from mutations of tertiary interactions known to play a general role in tRNA folding.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0022-2836
pubmed:author
pubmed:issnType
Print
pubmed:day
26
pubmed:volume
249
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
45-58
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
The presence of a D-stem but not a T-stem is essential for triggering aminoacylation upon anticodon binding in yeast methionine tRNA.
pubmed:affiliation
CNRS, Institut de Biologie Moléculaire et Cellulaire UPR 9002, Strasbourg, France.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't