Rit1は,tRNAの脊髄を修飾する酵素で,イニシアターと延長 tRNAの差別を媒介する
1Department of Microbiology, University of Umeå, Sweden.
Cell
|November 4, 1994
まとめ
RIT1遺伝子の突然変異は,イニシアターtRNAの改変を妨害し,翻訳開始と延長の両方でその使用を可能にします. この2'-O-リボシルフォスファート改変は,イニシアターと延長型tRNAの区別に極めて重要です.
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:
- タンパク質合成は,メチオニン tRNAのイニシアターと延長器の正確な差別に依存しています.
- このtRNA差別を制御する細胞因子は完全に理解されていません.
研究 の 目的:
- 翻訳中のメチオニンtRNA差別に関与する遺伝子を識別する.
- イニシエーターtRNA認識のメカニズムを解明する.
主な方法:
- 酵母における遺伝子スクリーニングは,tRNAの差別に影響を与える突然変異を特定するために行われます.
- 遺伝子の特徴づけと酵素活性分析.
- tRNAの改変パターンの分析.
主要な成果:
- RIT1遺伝子の突然変異が特定され,長引メチオニン tRNA.RNAの必要性を廃止しました.
- RIT1は,2 -O-リボシルリン酸塩移転酶をコードし,64位のイニシアターtRNAを修正する.
- RIT1の改変により,イニシアターtRNAは翻訳開始と延長の両方に参加することができます.
結論:
- RIT1によって触媒化された2 -O-リボシルフォスファート変異は,タンパク質合成において,イニシアターとエロゲーターtRNAを区別するために不可欠である.
- RIT1酵素は,ユカリオット細胞質イニシアターtRNAsのユニークな幹ループIV領域を認識します.
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...
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...


