RNA

Science (New York, N.Y.)
|July 23, 1971
PubMed
まとめ

成熟型トランスファーRNA (tRNA) の合成には前駆体処理と核酸変異が含まれますが,これらのイベントの正確な配列と機能はほとんど不明です. tRNA修飾酵素に関するさらなる研究は,生物学的プロセスにおけるtRNAの役割を理解するために不可欠です.

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In eukaryotic cells, transcripts made by RNA polymerase are modified and processed before exiting the nucleus. Unprocessed RNA is called precursor mRNA or pre-mRNA to distinguish it from mature mRNA.
Once about 20-40 ribonucleotides have been joined together by RNA polymerase, a group of enzymes adds a cap to the 5' end of the growing transcript. In this process, a 5' phosphate is replaced by modified guanosine that has a methyl group attached (7-methyl guanosine). This 5' cap helps the cell...
Transfer RNA Synthesis02:36

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One of the unique features of tRNA is the presence of modified bases. In some tRNAs, modified bases account for nearly 20% of the total bases in the molecule. Altogether, these unusual bases protect the tRNA from enzymatic degradation by RNases.
Each of these chemical modifications is carried by a specific enzyme, post-transcription. All of these enzymes have unique base and site-specificity. Methylation, the most common chemical modification, is carried by at least nine different enzymes, with...