まとめ
研究者らは,ヒトの胎盤から細胞質のイニシアター転送RNA (tRNA) を精製した. そのヌクレオチド配列は,他の哺乳類の細胞プラズマで見つかったイニシアターtRNAと同一であった.
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:
- イニシエーターtRNAは,すべての生物体におけるタンパク質合成の開始において重要な役割を果たします.
- 異なる種におけるイニシアターtRNAの特性を理解することで,進化の保存と機能的なニュアンスに関する洞察が得られます.
研究 の 目的:
- ヒトの胎盤からの細胞質イニシアターtRNAの核酸配列を浄化し,決定する.
- 人間の胎盤のイニシアターtRNA配列を他の哺乳類の細胞プラズマのイニシアターtRNAと比較する.
主な方法:
- ヒトの胎盤組織から細胞プラズマのイニシアターtRNAの分離と浄化.
- 精製されたtRNAの完全なヌクレオチド配列を決定するための高通量配列化.
主要な成果:
- 人間の胎盤から機能性サイトプラズマイニシアターtRNAの浄化に成功しました.
- 人間の胎盤のイニシアターtRNAの決定されたヌクレオチド配列は,他の哺乳類の細胞質源からのイニシアターtRNAと同一であることが判明しました.
結論:
- 人間の胎盤細胞プラズマのイニシアターtRNAは,他の哺乳類細胞プラズマのイニシアターtRNAと保存された нуклеотиド配列を共有しています.
- この配列同一性は,タンパク質合成におけるこの重要な分子の進化的保存の高度を示唆する.
関連する概念動画
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...
tRNA Activation
Aminoacyl-tRNA synthetases are present in both eukaryotes and bacteria. Though eukaryotes have 20 different aminoacyl-tRNA synthetases to couple to 20 amino acids, many bacteria do not have genes for all of these aminoacyl-tRNA synthetases. Despite this, they still use all 20 amino acids to synthesize their proteins. For instance, some bacteria do not have the gene encoding the enzyme that couples glutamine with its partner tRNA. In these organisms, one enzyme adds glutamic acid to all of the...
Initiation of Translation
Initiating translation is complex because it involves multiple molecules. Initiator tRNA, ribosomal subunits, and eukaryotic initiation factors (eIFs) are all required to assemble on the initiation codon of mRNA. This process consists of several steps that are mediated by different eIFs.
First, the initiator tRNA must be selected from the pool of elongator tRNAs by eukaryotic initiation factor 2 (eIF2). The initiator tRNA (Met-tRNAi) has conserved sequence elements including modified bases at...
First, the initiator tRNA must be selected from the pool of elongator tRNAs by eukaryotic initiation factor 2 (eIF2). The initiator tRNA (Met-tRNAi) has conserved sequence elements including modified bases at...
Leaky Scanning
During most eukaryotic translation processes, the small 40S ribosome subunit scans an mRNA from its 5' end until it encounters the first start AUG codon. The large 60S ribosomal subunit then joins the smaller one to initiate protein synthesis. The location of the translation initiation is largely determined by the nucleotides near the start codon as there may be multiple translation initiation sites present on the mRNA. Marilyn Kozak discovered that the sequence RCCAUGG (where R stands for...
Transcription Initiation
Initiation is the first step of transcription in eukaryotes. Prokaryotic RNA Polymerase (RNAP) can bind to the template DNA and start transcribing. On the other hand, transcription in eukaryotes requires additional proteins, called transcription factors, to first bind to the promoter region in the DNA template. This binding helps recruit the specific RNAP that can assemble on the DNA and start transcription.
The promoters and enhancers and their accessory proteins allow tight regulation of...
The promoters and enhancers and their accessory proteins allow tight regulation of...
tRNA Activation
Aminoacyl-tRNA synthetases are present in both eukaryotes and bacteria. Though eukaryotes have 20 different aminoacyl-tRNA synthetases to couple to 20 amino acids, many bacteria do not have genes for all of these aminoacyl-tRNA synthetases. Despite this, they still use all 20 amino acids to synthesize their proteins. For instance, some bacteria do not have the gene encoding the enzyme that couples glutamine with its partner tRNA. In these organisms, one enzyme adds glutamic acid to all of the...


