High impact information on Dars

• Expression of rat aspartyl-tRNA synthetase in Saccharomyces cerevisiae. Role of the NH2-terminal polypeptide extension on enzyme activity and stability [1].
• They behave as alpha2 dimers and display catalytic parameters in the tRNA aminoacylation reaction identical to those determined for the native, complex-associated form of aspartyl-tRNA synthetase isolated from rat liver [1].
• Molecular cloning and primary structure of cDNA encoding the catalytic domain of rat liver aspartyl-tRNA synthetase [2].
• The deduced amino acid sequence shows extensive homologies with that of yeast cytoplasmic aspartyl-tRNA synthetase, more than 50% of the residues being identical [2].
• In rat liver, aspartyl-tRNA synthetase occurs in two distinct forms: a dimeric enzyme and a component of a multienzyme complex comprising the nine aminoacyl-tRNA synthetases specific for arginine, aspartic acid, glutamic acid, glutamine, isoleucine, leucine, lysine, methionine, and proline [2].

Biological context of Dars

• The availability of the gene structure of AspRS could help to clarify molecular evolution of class II aaRS [3].
• The active DRS1 gene encoding the rat AspRS spans approximately 60 kb and is divided into 16 exons [3].
• One of the pseudogenes, psi DRS1, has a nt sequence 93% identical to that of the complete cDNA sequence of rat AspRS but several stop codons interrupt the coding sequence, thus identifying psi DRS1 to an inactive processed pseudogene [3].
• A phosphorylation site was introduced at the N-terminus of rat aspartyl-tRNA synthetase [4].

Anatomical context of Dars

• A wild-type rat liver aspartyl-tRNA synthetase, expressed in Chinese hamster ovary (CHO) cells, associates within the complex from CHO cells, whereas a mutant enzyme with a deletion of 34 amino acids from its amino-terminal extremity does not [5].

Other interactions of Dars

• A chimeric enzyme, made of the amino-terminal moiety of rat liver aspartyl-tRNA synthetase fused to the catalytic domain of yeast lysyl-tRNA synthetase, has been expressed in Lys-101 cells, a CHO cell line with a temperature-sensitive lysyl-tRNA synthetase [5].

References