まとめ
イーストのtRNA遺伝子は,中間配列を持つ前駆分子を生成することができます. 温度に敏感な突然変異体は,マイナーセリン型tRNA (tRNASerUCG) の前駆体を蓄積し,それを示唆する.
科学分野:
- 分子生物学は分子生物学である.
- RNA 処理 RNA 処理
- イースト遺伝学 イースト遺伝学
背景:
- tRNATyr と tRNAPhe のようないくつかの酵母 tRNA は,中間配列を含む前駆体から処理されます.
- 他のtRNAの先駆体は,温度に敏感な変異体の中に,許容できない温度で蓄積される.
研究 の 目的:
- ts136変異体における蓄積されたtRNA前駆体を分析する.
- 特定のtRNA種と,その中間配列の性質を特定するために.
主な方法:
- 温度感受性酵母変異体 (ts136) のtRNA前駆分子解析.
- 二次構造を分析するためにRNAase T1の消化.
- 以前に報告されたセリン型tRNAs (tRNASer) とサプレッサー変異との比較.
主要な成果:
- 19ヌクレオチドの干渉配列を持つ,小種のtRNASerの前駆体が見つかりました.
- 中間配列は,拡張されたベースペアリングと特定の切除/結合部位を持つ二次構造を可能にします.
- 蓄積された前駆体は,SUP-RL1抑制剤と関連した小型のtRNASerUCG種にのみ対応する.
結論:
- 特定された前駆体は,UCG.をデコードするマイナー酵母 tRNASerUCG の前駆体である.
- このマイナーなtRNASerUCGの変異は,SUP-RL1.1のリセシブ致死性を説明する可能性がある.
- これは,干渉配列を含む唯一の酵母tRNASer遺伝子を表している可能性があります.
関連する概念動画
RNA Splicing
Splicing is the process by which eukaryotic RNA is edited before its translation into protein. The RNA strand transcribed from eukaryotic DNA is called the primary transcript. The primary transcripts that become mRNAs are called precursor messenger RNAs (pre-mRNAs). Eukaryotic pre-mRNA contains alternating sequences of exons and introns. Exons are nucleotide sequences that code for proteins, whereas introns are the non-coding regions. In RNA splicing, introns are removed and exons are bonded...
pre-mRNA Processing
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 to it (7-Methyl guanosine). This 5’ cap helps the...
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 to it (7-Methyl guanosine). This 5’ cap helps the...
Non-LTR Retrotransposons
As the name suggests, non-LTR retrotransposons lack the long terminal repeats characteristic of the LTR retrotransposons. Additionally, both LTR and non-LTR retrotransposons use distinct mechanisms of mobilization. Non-LTR retrotransposons are further divided into two classes - Long interspersed nuclear elements (LINEs) and short interspersed nuclear elements (SINEs), both of which occur abundantly in most mammals, including humans. Some of the active non-LTR retrotransposons in humans are L1...
Transfer RNA Synthesis
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...
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...
Transcription Attenuation in Prokaryotes
Transcriptional attenuation occurs when RNA transcription is prematurely terminated due to the formation of a terminator mRNA hairpin structure. Bacteria use these hairpins to regulate the transcription process and control the synthesis of several amino acids including histidine, lysine, threonine, and phenylalanine. Transcription attenuation takes place in the non-coding regions of mRNA.
There are several different mechanisms used to attenuate transcription. In ribosome mediated...
There are several different mechanisms used to attenuate transcription. In ribosome mediated...
Transfer RNA Synthesis
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...
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...


