Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.7.6 (RNA polymerase)
 34,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A yeast aspartic acid tRNA with a 5' extension of 14 nucleotides was obtained by in vitro transcription with T7 DNA dependent RNA polymerase. This transcript, called extended tRNA(Asp) transcript, retains its aspartylation capacity with the same Km and only three times reduced kcat values as compared to those measured for canonical tRNA(Asp). This result indicates that the 5' extension of the amino acid acceptor stem of tRNA(Asp) does not interfere with recognition by aspartyl-tRNA synthetase. However, in contrast to the wild-type tRNA(Asp) transcript, the 5' extended molecule presents a reduced capacity to be mischarged by arginyl-tRNA synthetase, suggesting the existence of different structural requirements in aspartyl- and arginyl-tRNA synthetases for tRNA(Asp) recognition.
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PMID:Efficient aminoacylation of a yeast tRNA(Asp) transcript with a 5' extension. 222 85

Unmodified E. coli tRNA(Asp) was obtained by in vitro transcription with T7 RNA polymerase from a plasmid carrying a tRNA(Asp) sequence adjacent to the T7 promoter. The transcript exhibited almost the same level of amino acid acceptor activity as intact tRNA(Asp), and the kinetic parameters were also similar. However, substitution of the discriminator base (the fourth base from the 3'-end) markedly affected the amino acid acceptor activity. These results suggest that the discriminator base in tRNA(Asp) plays an important role in the recognition of aspartyl-tRNA synthetase.
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PMID:Discriminator base of tRNA(Asp) is involved in amino acid acceptor activity. 267 45

A 3.8 Kb DNA fragment, which contains the structural gene of aspartyl-tRNA synthetase (AspRS) and its flanking regions, has been fully sequenced by the combined M13/dideoxy chain terminator method. From the single open reading frame of correct length (1671 bp) we deduced an amino acid sequence consistent with that of several peptides of AspRS. No significant internal sequence repeats were observed in the primary structure of the protein. The AspRS gene (APS) has a codon usage pattern typical of non abundant proteins. S1 nuclease analysis of APS mRNA showed a major start 17 bases downstream from a "TATA box" and stops near an RNA polymerase terminator sequence.
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PMID:Nucleotide sequence of the gene coding for yeast cytoplasmic aspartyl-tRNA synthetase (APS); mapping of the 5' and 3' termini of AspRS mRNA. 351 27

Several classes of small noncoding RNAs are key players in cellular metabolism including mRNA decoding, RNA processing, and mRNA stability. Here we show that a tRNA(Asp) isodecoder, corresponding to a human tRNA-derived sequence, binds to an embedded Alu RNA element contained in the 3' UTR of the human aspartyl-tRNA synthetase mRNA. This interaction between two well-known classes of RNA molecules, tRNA and Alu RNA, is driven by an unexpected structural motif and induces a global rearrangement of the 3' UTR. Besides, this 3' UTR contains two functional polyadenylation signals. We propose a model where the tRNA/Alu interaction would modulate the accessibility of the two alternative polyadenylation sites and regulate the stability of the mRNA. This unique regulation mechanism would link gene expression to RNA polymerase III transcription and may have implications in a primate-specific signal pathway.
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PMID:Misfolded human tRNA isodecoder binds and neutralizes a 3' UTR-embedded Alu element. 2193 58