関連する実験動画

Updated: Apr 28, 2026

Isolation of Translating Ribosomes Containing Peptidyl-tRNAs for Functional and Structural Analyses
11:19

Isolation of Translating Ribosomes Containing Peptidyl-tRNAs for Functional and Structural Analyses

Published on: February 25, 2011

20.5K

単一のG•Uペアに基づく選択的tRNAアミノアシレーションメカニズム

Masahiro Naganuma1, Shun-ichi Sekine2, Yeeting Esther Chong3

  • 11] RIKEN Systems and Structural Biology Center, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan [2] Department of Biophysics and Biochemistry and Laboratory of Structural Biology, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan [3] RIKEN Structural Biology Laboratory, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan.

Nature
|June 12, 2014
PubMed
まとめ

アミノアシル-tRNA合成酵素 (aaRS) は遺伝子コードを確立する. ある研究では,転送RNA (tRNA) の単一の塩基対 (G3•U70) が,アラニル-tRNA合成酵素 (AlaRS) によってアミノ酸の選択を誘導し,遺伝コードの正確性を確保する方法が明らかにされました.

さらに関連する動画

Residue-specific Incorporation of Noncanonical Amino Acids into Model Proteins Using an Escherichia coli Cell-free Transcription-translation System11:47

Residue-specific Incorporation of Noncanonical Amino Acids into Model Proteins Using an Escherichia coli Cell-free Transcription-translation System

Published on: August 1, 2016

16.5K
Quantification of the Abundance and Charging Levels of Transfer RNAs in Escherichia coli10:34

Quantification of the Abundance and Charging Levels of Transfer RNAs in Escherichia coli

Published on: August 22, 2017

9.2K

関連する概念動画

tRNA Activation02:26

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...
17.9K
tRNA Activation02:26

tRNA Activation

7.5K
Transfer RNA Synthesis02:36

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...
10.2K
Transfer RNA Synthesis02:35

Transfer RNA Synthesis

3.0K
Improving Translational Accuracy02:07

Improving Translational Accuracy

Base complementarity between the three base pairs of mRNA codon and the tRNA anticodon is not a failsafe mechanism. Inaccuracies can range from a single mismatch to no correct base pairing at all. The free energy difference between the correct and nearly correct base pairs can be as small as 3 kcal/ mol. With complementarity being the only proofreading step, the estimated error frequency would be one wrong amino acid in every 100 amino acids incorporated. However, error frequencies observed in...
11.5K
Leaky Scanning02:28

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...
4.5K