まとめ
シルクワームの細胞内のリボヌクレアゼP (RNAase P) と3'-5'ヌクレアゼは,tRNA前駆者を処理する. RNAase Pは5'核酸を除去し,3'-5'核酸は2段階の成熟プロセスで3'核酸をトリミングする.
科学分野:
- バイオケミストリー バイオケミストリー
- 分子生物学は分子生物学である.
- RNA 処理 RNA 処理
背景:
- リボヌクレアゼP (RNAase P) と3−5ヌクレアゼは,E. coliのtRNA合成に不可欠である.
- これらの酵素活動は,Bombyx mori.の糸腺細胞にも存在しています.
研究 の 目的:
- Bombyx mori tRNA合成におけるRNAase Pと3−5核酵素の役割と特性を調査する.
- シルクワームの細胞におけるtRNA前成熟のメカニズムを解明する.
主な方法:
- ボムビックス・モリ (Bombyx mori) のシルク腺細胞からの亜細胞抽出物が使用されました.
- クリーバージアッセイは,E. coliとBombyx moriのプレ-tRNAを用いて実施した.
- RNAの指紋と5端フォスファート分析を用いた.
- インビトロ加工中介物のシーケンス分析が行われました.
主要な成果:
- Bombyx mori RNAase Pは,E. coliのプリ-tRNAをE. coli酵素と同じ方法で割った.
- Bombyx mori RNAase Pは,非tRNA基板を裂けなかった.
- ボンビックス・モリ・プレ-tRNAは,余分な5つと3つのヌクレオチドを持っています.
- 原料の抽出物は,余分な2つの核酸を除去するが,精製されたRNAase Pは5つの核酸のみを除去する.
- Bombyx mori RNAase P.の基底は,大きなのプリ-tRNAのみであった.
結論:
- ボンビックス・モリRNAase Pと3−5核酶は,tRNA前成熟に協力する.
- プリ-tRNA処理は2段階で行われます:RNAase Pによって5つのヌクレオチドが除去され,その後3つのヌクレオチドが3〜5のヌクレアゼによってトリミングされます.
関連する概念動画
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...
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...
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...
Pre-mRNA Processing: Modification of pre-mRNA Ends
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...
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...
Pre-mRNA Processing: 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...
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...


