Kinetics of homologous and heterologous aminoacylation with yeast phenylalanyl transfer ribonucleic acid synthetase

Roe, Bruce A.; Sirover, Michael A.; Dudock, Bernard S.

doi:10.1021/bi00745a018

Cited by 98 publications

(67 citation statements)

References 43 publications

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“…Under all these experimental conditions we did not find any significant difference between the K , values measured in cognate or non-cognate systems. This observation is similar to studies with other synthetases [l, 3,26,28,31] and suggests that strong interactions do occur between the wrong tRNAs and the valyl-tRNA synthetase from B. stearothermophilus.…”

Section: Characteristics Of the Misaminoacylation Reactionssupporting

confidence: 89%

Incorrect Aminoacylations Involving tRNAs or Valyl-tRNA Synthetase from BacilIus stearothermophilus

et al. 1974

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Numerous misacylations occur on heterologous systems containing unfractionated tRNAs from yeast or from Bacillus stearothermophilus and pure valyl-tRNA synthetase from B. stearothermophilus or from yeast, when special aminoacylation conditions are used. I n the homologous system and in heterologous systems where the unfractionated tRNAs and the enzyme originate from prokaryotic organisms (B. stearothermophilus and Escherichia coli), the errors are seldom. This phenomenon is explained by competition effects between the cognate tRNAVa1 and noncognate tRNAs for the valyl-tRNA synthetase. But using pure tRNA species, errors can be observed in such systems, even under classical assay conditions; in particular it was shown that the valyl-tRNA synthetase from B. stearothermophilus catalyses the misacylation of E. coli tRNAIle and tRNA,Met and of yeast tRNA,Met and tRNAPhe. These reactions are characterized by K , values slightly increased as compared to the value obtained in the cognate system and by V values decreased by a factor of about 40 to 3000 compared to the cognate tRNA species. I n the presence of dimethylsulfoxide, the rate and the extent of those misacylation reactions are enhanced. I n the case of E . coli tRNAPhe, the misacylation occurs only in the presence of the organic solvent. I n no case however, new aminoacylation errors are induced a t high temperature (50-75 "C) in the presence of the thermostable valyl-tRNA synthetase from B. stearothermophilus ; only an increase of the rates of the aminoacylation reactions which already occur a t 30 "C has been observed a t higher temperature. Thus organic solvent and heat must have distinct effects on the essential parameters determining the specificity of the tRNA aminoacylation reactions.Also it has been observed that the most easily misacylated tRNA species by valyl-tRNA synthetase from B. stearothermophilus are the same as those which are misacylated by the valyltRNA synthetases from E . coli and from yeast. This observation suggests the existence of a family of tRNAs containing besides of tRNAVB', other tRNAs such as tRNATle, tRNAyet and tRNAPhe, and which are likely to be related from a phylogenic point of view. Moreover these tRNA species have also been found to be easily misacylated by other aminoacyl-tRNA synthetases namely the enzymes specific for isoleucine and phenylalanine, thus suggesting more generally the existence of interacting tRNA-aminoacyl-tRNA synthetase families.The possibility of the tRNAs to be enzymatically mischarged with a wrong amino acid seems to be a rather general feature as numerous incorrect aminoacylation systems have now been described [i -31 (and references therein). These mischarging reactions have especially been detected in vitro, under various experimental conditions, either in heterologous systems where the enzyme and the tRNA came from different sources, but also in homologous systems, where one pure tRNA species interacts Enzyme. Valyl-tRNA synthetase (EC 6.1.1.9). Eur. J. Biochem. 45 (1974)with one non-cognate pure ...

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Section: Characteristics Of the Misaminoacylation Reactionssupporting

confidence: 89%

Incorrect Aminoacylations Involving tRNAs or Valyl-tRNA Synthetase from BacilIus stearothermophilus

et al. 1974

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“…The mixture was stirred at 4°C for 20-30 minutes, and centrifuged at l5,OOOg for 30 minutes. DEAE-cellulose (Sigma) was prepared as described by Roe et al (23). and was added to the supernatant to make a 25% (volumeivolume) suspension.…”

Section: Methodsmentioning

confidence: 99%

Evidence for impaired t cell dna methylation in systemic lupus erythematosus and rheumatoid arthritis

Richardson

Scheinbart

Strahler

et al. 1990

Arthritis & Rheumatism

522

338

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Procainamide and hydralazine inhibit T cell DNA methylation and induce autoreactivity in cloned CD4+ T cells. These drugs also induce an autoimmune syndrome, suggesting a possible relationship between DNA hypomethylation, T cell autoreactivity, and certain autoimmune diseases. To test this relationship, DNA methylation was studied in T cells from patients with rheumatoid arthritis and patients with systemic lupus erythematosus, and was found to be impaired. These results support a relationship between DNA hypomethylation and some forms of autoimmune disease.Cytosine methylation in regulatory sequences of some genes is associated with transcriptional inactivation, while hypomethylation of these sequences is associated with active transcription (1-4). DNA methyltransferase inhibitors such as 5-azacytidine inhibit methylation of newly synthesized DNA and allow From the

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“…Roe et al [16] have proposed that the yeast phenylalanyl-tRNA synthetase recognizes the stem of the dihydrouridine arm and nucleotide 4 in the 3'-terminal amino acid arm. This group has also found [17] that the rate of heterologous charging of tRNAs with the phenylalanyl-tRNA synthetase is greatly influenced by the site of the dihydrouridine loop and by the modification of a base in the stem of the dihydrouridine arm.…”

Section: Reconstruction Of a Partial Sequence For Serine Trnamentioning

confidence: 99%

Nucleotide Sequences of Rat-Liver Serine tRNA. Structure of Serine tRNA3 and Partial Nucleotide Sequences of Serine tRNA2a

1975

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The purification of serine tRNA, from rat liver and the identification of the products of digestion with pancreatic and T, ribonucleases are described.The following primary sequence was determined by nucleotide overlaps and by analysis of a partial T,-ribonuclease digest: The analysis of a TI-ribonuclease digest of a further serine tRNA fraction, designated serine tRNA,, is also described. This fraction consists mainly of a species coding for UCG. From these data we can tentatively derive part of the structure of this molecule.The sequences reported here are compared to those of known serine tRNAs from Escherichia coli, yeast and rat liver. The possible site of synthetase recognition of the isoacceptor serine tRNAs is discussed.Comparison of the sequences of isoacceptor tRNAs give us useful information about the relationship between structure and function of these molecules. The serine-specific tRNAs are especially suitable for this purpose since serine is the only amino acid having six codons showing different bases in all three positions. Up to now the sequences of Escherichia coli tRNAgGA, UCG, ucu and E. coli tRNAS6;,,, AGU as well as those of the yeast-and rat liver tRNA&,, ucc, UCA are known [l-41. Since the coding properties of E. coli serine tRNAs differ from those originating from eukaryotic organisms [ 5 ] , it is of interest to Abbreviations. Abbreviations for polynucleotides follow CBN rules, see Eur. J. Biochem. 15 (1970) Definition. AZe0 unit, the amount of material contained in 1 ml of solution which gives an absorbance of 1 at 260 nm when measured in a I-cm path length cell.

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Kinetics of homologous and heterologous aminoacylation with yeast phenylalanyl transfer ribonucleic acid synthetase

Cited by 98 publications

References 43 publications

Incorrect Aminoacylations Involving tRNAs or Valyl-tRNA Synthetase from BacilIus stearothermophilus

Incorrect Aminoacylations Involving tRNAs or Valyl-tRNA Synthetase from BacilIus stearothermophilus

Evidence for impaired t cell dna methylation in systemic lupus erythematosus and rheumatoid arthritis

Nucleotide Sequences of Rat-Liver Serine tRNA. Structure of Serine tRNA3 and Partial Nucleotide Sequences of Serine tRNA2a

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