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Influence of tRNA tertiary structure and stability on aminoacylation by yeast aspartyl-tRNA synthetase
- Publication Year :
- 1993
-
Abstract
- Mutations have been designed that disrupt the tertiary structure of yeast tRNA(Asp). The effects of these mutations on both tRNA structure and specific aspartylation by yeast aspartyl-tRNA synthetase were assayed. Mutations that disrupt tertiary interactions involving the D-stem or D-loop result in destabilization of the base-pairing in the D-stem, as monitored by nuclease digestion and chemical modification studies. These mutations also decrease the specificity constant (kcat/Km) for aspartylation by aspartyl-tRNA synthetase up to 10(3)-10(4) fold. The size of the T-loop also influences tRNA(Asp) structure and function; change of its T-loop to a tetraloop (-UUCG-) sequence results in a denatured D-stem and an almost 10(4) fold decrease of kcat/Km for aspartylation. The negative effects of these mutations on aspartylation activity are significantly alleviated by additional mutations that stabilize the D-stem. These results indicate that a critical role of tertiary structure in tRNA(Asp) for aspartylation is the maintenance of a base-paired D-stem.
- Subjects :
- Base pair
Acylation
Aspartate—tRNA ligase
Saccharomyces cerevisiae
Aspartate-tRNA Ligase
Molecular Sequence Data
Aminoacylation
Biology
medicine.disease_cause
Tetraloop
stomatognathic system
RNA, Transfer
parasitic diseases
Genetics
medicine
Mutation
Base Sequence
Temperature
biology.organism_classification
Molecular biology
Protein tertiary structure
enzymes and coenzymes (carbohydrates)
Kinetics
Biochemistry
Transfer RNA
biology.protein
Nucleic Acid Conformation
Subjects
Details
- Language :
- English
- Database :
- OpenAIRE
- Accession number :
- edsair.doi.dedup.....1da76860238564193f7765a01022f4c9