Linked Life Data

9657697

Source:http://linkedlifedata.com/resource/pubmed/id/9657697

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
27
pubmed:dateCreated
1998-7-30
pubmed:abstractText
Sequence-specific interactions between Escherichia coli glutaminyl-tRNA synthetase and tRNA(Gln) have been shown to determine the apparent affinity of the enzyme for its cognate amino acid glutamine during aminoacylation. Specifically, structural and biochemical studies suggested that residues Asp66, Tyr211, and Phe233 in glutaminyl-tRNA synthetase could potentially facilitate cognate amino recognition through their specific interactions with both A76 of tRNA(Gln)++ and glutamine. These residues were randomly mutated and the resulting glutaminyl-tRNA synthetase variants were screened in vivo for changes in their ability to recognize noncognate tRNAs and retention of tRNA-glutaminylation activity. When the variants selected in this way were characterized in vitro, they all showed dramatic decreases in apparent affinity (KM) for glutamine but little or no change in cognate tRNA affinity. Conservative replacements such as Y211F, F233L, and D66E resulted in 60-, 19-, and 18-fold increases compared to wild-type in the KM for glutamine, respectively, but had little effect on the turnover number (kcat). Nonconservative replacements affected both KM for glutamine and kcat; Y211S, F233D, and D66F displayed 1700, 3700, and 1200-fold decreases in kcat/KM for glutamine compared to wild-type. Double mutant cycle analysis indicated that Tyr211, and Phe233 interact strongly to enhance glutamine binding. These data now show that Asp66, Tyr211 and Phe233 mediate tRNA-dependent cognate amino acid recognition via the invariant 3'-terminal adenosine of tRNA(Gln).
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
7
pubmed:volume
37
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
9836-42
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
The terminal adenosine of tRNA(Gln) mediates tRNA-dependent amino acid recognition by glutaminyl-tRNA synthetase.
pubmed:affiliation
Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520-8114, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.