まとめ
ミトコンドリアDNA (mtDNA) の重鎖RNA配列のrRNA,ポリ(A) 含有RNA,tRNAは連続したトランスクリプトを形成する. これは,単一のポリシストロニックRNA分子に転写され,成熟した種に処理されることを示唆しています.
科学分野:
- 分子生物学は分子生物学である.
- 遺伝学 遺伝学とは
- バイオケミストリー バイオケミストリー
背景:
- ミトコンドリアDNA (mtDNA) は,細胞呼吸に必要な要素をコードする.
- ミトコンドリアの遺伝子発現を理解するには,mtDNAの転写と処理を理解することが重要です.
研究 の 目的:
- HeLa細胞 mtDNAの重 (H) 鎖のメッセンジャーRNA (mRNA) 前駆体の組織と処理を調査する.
- コード配列と,H鎖mRNAの3'-endにあるtRNA遺伝子の関係を決定する.
主な方法:
- HeLa細胞のmtDNAから推定mRNAの3'-end近接セグメントの部分シーケンシング.
- 配列化されたmRNAセグメントと対応するDNA配列の並び合わせ.
主要な成果:
- 個々のmRNAコード配列の3'-endヌクレオチドは,tRNA遺伝子または他のmRNAコード配列のすぐ隣にあることが判明しました.
- これらの発見は,以前のデータと組み合わせて,H鎖のrRNA,ポリ(A) 含有RNA,tRNAのコード配列の連続性を示しています.
結論:
- mtDNAの重鎖は,単一のポリシストロニックRNA分子として転写される可能性が高い.
- この前駆体RNAは,その後,精密な内核分解分裂によって成熟したrRNA,ポリ(A) 含有RNA,tRNA種に処理され,しばしばtRNA遺伝子と関連付けられます.
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...
Mitochondrial Precursor Proteins
Mitochondrial precursors are partially unfolded or loosely folded polypeptide chains. Newly synthesized precursors are inhibited from spontaneously folding into their native conformation by the cytosolic chaperones, heat shock proteins 70 (Hsp70), and mitochondrial import stimulation factors (MSFs). Precursors bound to MSFs are guided to the TOM70-TOM37 receptors, while precursors bound to Hsp70 chaperones are targetted to TOM20-TOM22 receptor complexes.
Most of the mitochondrial precursors...
Most of the mitochondrial precursors...
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...
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...


