Format

Send to

Choose Destination
See comment in PubMed Commons below
Science. 1991 Jun 21;252(5013):1696-9.

Identity elements for specific aminoacylation of yeast tRNA(Asp) by cognate aspartyl-tRNA synthetase.

Author information

1
Laboratoire de Biochimie, Institut de Biologie Moléculaire et Cellulaire du CNRS, Strasbourg, France.

Abstract

The nucleotides crucial for the specific aminoacylation of yeast tRNA(Asp) by its cognate synthetase have been identified. Steady-state aminoacylation kinetics of unmodified tRNA transcripts indicate that G34, U35, C36, and G73 are important determinants of tRNA(Asp) identity. Mutations at these positions result in a large decrease (19- to 530-fold) of the kinetic specificity constant (ratio of the catalytic rate constant kcat and the Michaelis constant Km) for aspartylation relative to wild-type tRNA(Asp). Mutation to G10-C25 within the D-stem reduced kcat/Km eightfold. This fifth mutation probably indirectly affects the presentation of the highly conserved G10 nucleotide to the synthetase. A yeast tRNA(Phe) was converted into an efficient substrate for aspartyl-tRNA synthetase through introduction of the five identity elements. The identity nucleotides are located in regions of tight interaction between tRNA and synthetase as shown in the crystal structure of the complex and suggest sites of base-specific contacts.

PMID:
2047878
[Indexed for MEDLINE]
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire
    Loading ...
    Support Center